MadModder
Gallery, Projects and General => Project Logs => Topic started by: arnoldb on June 13, 2011, 02:58:53 PM
-
Shop time has been limited and slow the last couple of weeks, and I suffer from an overload of projects as well...
A while ago, I finished the basic layout for my "garden railway" - well, to give it a better name, it is a stoep (porch) track. Absolutely MASSIVE :lol::
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2401.JPG)
When I got the tracks last year, there were no joiners; the supplier in South Africa I ordered the track from excluded the joiners even though I specifically asked for them :bang:, and I ended up making a crude handful using M2 screws:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_2424.jpg)
For now I have the track loop loosely laid and joined together - except for the points and siding which I will make at a later date.
I gave Fred the loco (http://www.homemodelenginemachinist.com/index.php?topic=6644.0) a run around the track, and soon learnt that plastic track ties and his spirit fired pot boiler does not mix well :doh:
So I started on a Cracker locomotive that is a simple build - normally - and have been making a tiny bit of inroads on it.
First up were the gears. I used the rack "hob" method, and was going to do a full how-to write-up, but things didn't quite work as planned, so for now the how-to is on hold. I know where the problems raised their heads, and the next time around making gears should be a lot better - and then I can hopefully do a write-up. I did end with a serviceable set of gears though. The toolbit to cut the hob, the hob and the gears:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2658.JPG)
Yesterday I started off on the frames and footplate for the loco - just bits of steel plate sawn from an old UPS cover that I had to introduce to the blowtorch to get rid of the powder coating, then a wire wheel in the drill press to remove the gunk that was left, and finally drilled and filed to size. I could have used the mill to trim them to size, but setting up and holding thinnish plate (1.6mm) takes a lot of effort and time, so the files were quicker, and besides, it is terribly cold here and there's nothing like a stint of filing to warm one up :lol: So this is where things stand for now:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2662.JPG)
The plates are nice and straight; it's camera lens aberration that makes them look curved :med:
This build might be a bit slow; some work projects look like interfering with my hobby time - and I can't stand the cold in the shop...
:beer:, Arnold
-
What gauge is the track, Arnold?
And how cold is it, really? If no ice on the inside of the windows, it's just a bit on the cool side of temperate.
Andy
-
Andy,
It's not really cold, wuzies in Namibia :lol: :lol: :lol: :lol:
( Don't tell Arnold) :)
:beer:
DaveH
-
It's not really cold, wuzies in Namibia
DaveH
:lol: :lol: :lol: :lol: :lol: Tart,, is the word i would use Dave :lol: :lol: :lol: :)
Nice going Arnold ,,,,,,,,,,, i have never tried cutting gears that way :med: :clap: :clap: :clap: :clap:
Rob
-
:lol: :lol: :lol: - aye; us Namibians are scared of the cold; must be partly cold-blooded, as I can't work at 10C or less :doh:
Seriously though, last week for a couple of days it dropped down to -3C by 5pm and one night down to -13C - Really not used to that!
Andy, it's 0 gauge (32mm) track. I wish I could have 2.5" so I could build a real loco to drive, but my yard is too sloped for that.
Rob, cheers mate; I need to refine a few things for the gearcutting still.
:beer:, Arnold
-
Good morning Arnold,
sure remember it being very cold in Windhoek. When developing Van Eck Power station and Tsumeb & Okahanja depots there were some nights down to -12. But always followed by glorious days.
by the way do you also make Kudo biltong?
have fun with your loco
Bernard
-
Hi Bernard
:lol: I have fond memories of Van Eck from my apprentice days at SWAWEK - had to crawl in amongst the generator control circuits to get at circuit boards quite a bit. We used to joke you could walk through the plant with your hands in your pockets and still come out with them dirty.
And yes, I do make a bit of biltong; though I'm partial to Gemsbok. In fact, weekend before last I lost shop time to a bit of butchering, but now the freezer is stocked for months to come.
:beer:, Arnold
-
Well, finally a bit of an update...
Today was a nice and mild day, so I decided I didn't need warming up by filing and milled the cut-outs in the footplate:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2669.JPG)
The buffer beams and axle bushes followed. The axle bushes was just a simple turning job in brass. I made the buffer beams from some 60x10mm aluminium bar; unfortunately it was rather soft extruded bar, so it was a bit of a challenge tapping all the M2 threads in them, especially the ones on the ends, as I could not even use the tapping guide for those...:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2670.JPG)
My one concern up to this point was whether the pinion gear spacing would work; I couldn't resist checking:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2671.JPG)
:D Works a treat; just a hint of free play but that's fine.
I cut the axles as well and assembled the frame. All the bits done so far:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2673.JPG)
I started looking at the engine, and realised I have a wee bit of a problem... The only pipe I have to make the boiler from is 42mm in diameter rather than the plans' 35mm - which leaves no room for the engine sticky-outy-bits :palm: - So I have to re-think the engine mounting a bit; might have to offset it from the frames by about 5mm to get the necessary clearance...
:beer:, Arnold
-
Arnold,
Looking good :thumbup:
I am a bit concerned about that banana shapped steel rule you have there :lol: :lol: :lol:
:beer:
DaveH
-
:D Cheers Dave :beer: - I use the curved steel rule to check that things are straight and in-line... If I used a normal straight-edged one, nothing I make would ever work :lol:
I'm still pondering the engine... I assigned one brain cell to that problem, and forced my other one to multi-task between all the other day-to-day life issues.
Like turning wheels...
Turning up these small loco wheels is actually a tricky little chore, so I tried a different method to what I've used in the past.
First I turned a bit of cruddy HRS down to the outer diameter needed, and put some parting grooves in it to a mm or two below the tire diameter - using convenient readings on the leadscrew dial to index them across:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2674.JPG)
Then I removed most of the excess stock off the rim sections, leaving them about 0.2mm over-size:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2675.JPG)
A couple of minutes at the bench grinder with a new 8mm HSS square tool blank, and I had a good form tool to turn the wheel profiles in one go. Using the same indexing from the leadscrew, I used the top slide combined with the cross slide to get the first wheel done to size, noted the reading on the cross slide, locked the top slide and just repeated to the same infeed depth on the cross slide at each index point off the leadscrew. Easy-peasy :D :
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2676.JPG)
After a quick 9.8mm drill and 10mm reamer through the whole lot, I faced and parted off each wheel in turn. Then I turned up and parted sections off some 12mm hex brass for a light press fit for the wheel hubs (just 0.01mm/0.0005" over size), drilled and tapped for m3 grub screws, and ended up with this lot:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2677.JPG)
Pressed each wheel and hub together with a dab of green retainer for a little extra security, and the wheels were done. A trial fit in the frames:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2679.JPG)
The gears mesh beautifully; much better than I expected from this home-brew lot, so I'm a happy chappy :ddb: :ddb:
I do need to replenish my stock of short M3 grub screws though; had to use some long ones here...
It's always gratifying to see it up on rails :D:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2680.JPG)
:beer:, Arnold
-
Looking good, Arnold. So, here's a question... How come the tires on the wheels are tapered? I would think they should be flat???
Chuck
-
Arnold,
Coming along nicely, must be warm in Namibia :D
You got two brain cells, have you had a sneaky brain cell transplant. :lol: :lol: :lol:
There again I would think unused brain cells in Namibia are quite common. :lol: :lol: :lol:
Looking good Arnold. :thumbup:
:beer:
DaveH
-
Looking good, Arnold. So, here's a question... How come the tires on the wheels are tapered? I would think they should be flat???
Chuck
I cant remember all the reasons why, but it is something to do with helping stability when encountering any sort of non-straight tracks, the camber on the wheels really help staying on the rails in the corners.
Tim
-
Reason for the taper is that a solid axle on a locomotive has no differential like a car for going around corners. When going around a curve the outer wheel will ride higher on the taper giving it a faster speed than the inner wheel. I hope this makes sense.
Bernd
-
It's looking great, Arnold. They are a neat little loco.
Dean
-
Arnold.
I don't do locos/ railways. Don't know what a Cracker is........ ::)
What you've done so far, is looking good. :clap:
Quietly watching it develop. I'm sure it will be a "cracker", when finished...... :thumbup:
Bernd.
That makes sense to me! :smart:
(I thought it was for the centralising, diabolo effect)..... :palm:
David D
-
Nice build Arnold - any chance of a pic of what it will look like when finished?? Drawings perhaps?
BTW - introduced my wife to Africa last December, and after a sot introduction in Cape Town and Stellenbosch, next trip was a tour around Namibia. I'd experienced your beautiful country on numerous visits about 10 years ago when resurfacing Hardap Dam, and promised her a visit. had a fantastic time, and enjoyed the very high standard of some of the game lodges, but driving around Windhoek, Swakop, Uis, and Etosha was incredible. I can categorically state that it was a vacation of a lifetime. People are fantastic, warm, welcoming, and distinctly practical (try getting a 'bakkie' tire on a Corolla - successful), and everyone seems to know one another - let me guess to see if you know Dudley Biggs....
best, Allan
-
Chuck, Thanks for checking in :beer: - Like Bernd said, it's mostly used for the speed differential in cornering. On real trains, in a straight line, it also helps to keep the engine and rail cars from snaking around thus saving wear on the wheel flanges and track insides, as well as providing a more comfortable ride for passengers (think "horizontal" sea-sickness). In the model world, we don't care about the passengers, but it does help to eliminate some running friction - something my first loco with flat wheels suffers from quite a bit.
:lol: Dave, it is a bit warmer :). Life was generous with me; I actually received 3 brain cells - but I didn't receive good looks, good luck or any of that stuff :lol: 2 Brain cells are used for day-to-day living; the third is reserved for matters related to the fairer sex; that one's not allowed in the shop at all :lol: - it causes havoc and nothing gets done! Besides, without the looks, luck and all of that, the 3'rd cell is permanently in overdrive on it's own mission :lol: :lol:
:beer: Thanks Dean. I just hope it will work with my modifications...
David, thanks :thumbup: - when this one's done I'll take a note from your book and build a Stirling - well after making some tooling and possibly attempting a fairly unique engine build...
Thanks Allan :beer: - There's quite a lot of Crackers on HMEM - Shred's is particularly nice and Tony Bird has built some very well-running variants of the Cracker. The plans are available from John-Tom (http://www.john-tom.com/html/SteamPlans2.html). The basic Cracker plans are extremely simple and lends itself to the builder's imagination, but I wouldn't recommend the Cracker as a very first project - exactly because of that, as well as some construction and assembly details that are not clear from the plans.
:D Glad you like Namibia; I go to Hardap once or twice a year for a weekend fishing trip; nice big carp and really big catfish in there. If you did Swakop/Uis/Etosha, did you go through Damaraland - Stunning over there. Around Swakop a trip to the Moon Landscape and welwitchias is always a winner. The Namib desert really gets under one's skin.
And :lol: - I'm not surprised the people could make a bakkie tire fit a Corolla - over here bakkies and Corollas are pretty much the bread-and-butter transport... :scratch: Nope I don't know Dudley... Though I might have met him somewhere along the line in the local watering holes; I'm TERRIBLE at names!
Well, this morning my engine-building brain cell farted... After waiting for the stink to clear, and using Charlie Docstader's Valve Gear program (http://www.jf2.com/bcwrr/Dockstader-Valve-Gear.html) for checking things and running simulations with new dimensions, things looked to be on the up-and-up and good to go.
For the port block, the steam and exhaust ports needed to be moved lower to use available space around the boiler. Seeing as I'd have to do some fairly deep-drilling in the port block to, I decided to make the engine a double-acting rather than the single acting oscillator the plans show. The new design needs a thicker port block than the plans - preferably about 4m thick. I don't have 4mm thick brass plate, but a while ago I bought a ~4mm thick and ~200mm diameter phosphor bronze "washer" from my local supplier at a whim (and good discount!). A bit sawn from it:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2681.JPG)
After more sawing, I had about a third of that section cut out - which was then milled to the engine port-block size and laid out. Then I started drilling some port holes:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2682.JPG)
2mm drill for 3mm deep, then 1.6mm drill 20mm deep
All the port holes were drilled to intercept the steam passages; I made an oops on one and drilled right through the port block :doh: - fortunately where a bit have to be soldered on. The back of the port block, showing a lot of scars from over-vigorous de-burring (I forgot that PB will "grab" a drill bit - even if twirled manually - hence the scars around the big hole) - but more importantly the broken through port hole, a line to mark the center through it, and two groups of four punch-marks around the line:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2683.JPG)
:palm: Not up to my normal standard - I'm actually feeling bad showing such a bad-looking part. Mister's Moderator, can we please get an "Embarrassed" Smiley ?
I needed a steam and exhaust connector to the port block, and all this faffing around was to get those down to a level where there would be space around the boiler to make those connections. The original plans call for a connection soldered behind the top port faces - I don't have that space - so I moved it down. A bit of 5mm hex brass was turned down and threaded M5 on each end, with a nice 90 degree countersink in the "steam" side (more on that later) and centre drilled at 2mm for about 12mm deep each end while on the lathe. Now the reason for those punch marks... The mentioned hex brass is to be soldered to the port block. Ordinary soft solder (electronics lead based type) could work, but I prefer silver solder (or hard solder or silver brazing) around steam bits. The silver solder (and flux) needs a gap to wick through, and the punch marks raises some high spots to allow just for this. A bit of soldering with a plumber's torch later:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2684.JPG)
After a quick pickle in warm citric acid (~10 minutes) and a rub-down with scotch-brite and another rub of the port face over some 800 emery, the block looked better and I could drill the bottom port holes through into the connector - this time without breaking through the back side ::):
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2685.JPG) (http://www.nam-engineering.com/cm/displayimage.php?pid=3173&fullsize=1)
I love my camera; it shows all the bad detail - even on a reduced photo :lol:
And a final drill through from the port connector sides using a "wiggly wire" to feel when the drill bit comes through:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2686.JPG)
Finished port block - back side:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2688.JPG)
And piston side - dings and all; fortunately there are no dings where things matter :) :
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2687.JPG)
:beer:, Arnold
-
Arnold,
Looks really good, comming along nicely. :thumbup:
Nicely posted as well, a real pleasure to read your posts Arnold :clap: :clap: :clap:
:beer:
DaveH
-
Looking good Arnold :thumbup: nice bit of soldering :clap:
Stew
-
Nicely done Arnold. :clap:
Like the idea of centre pops, to hold off for silver solder penetration...... :thumbup:
David D
-
Dave, Stew & David - Thanks chaps :beer:. Today's soldering wasn't quite as neat though...
David - the centre pops trick I picked up from other modellers - but it's good to show little bits like that for those that have not seen it or are newer members.
A bout of 'flu has kept me from being my normal self for the past week - so I spent yesterday in bed and slept most of it off.
This morning I felt quite a bit better, so started on the cylinder from a bit of 10mm hex brass stock:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2695.JPG)
I wasn't in the mood to make up a reamer to ream the cylinder, and the hand reamers I have are no good for a blind cylinder, so I used an 8mm end mill to run in to final depth - with a very fine feed both in and out this makes a pretty good finish in the cylinder - as long as the lathe's tailstock is very well aligned with the headstock; which mine fortunately (well, after a lot of work adjusting in the past!) is:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2696.JPG)
For the cylinder port face I used a bit of the same 4mm bronze the port block is made from - just poked some holes in the correct places and gave it a shallow counter bore with an 8mm slot mill:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2697.JPG)
Flipped it end-over end, and ran a 10mm ball nose mill over the back side to match the cylinder outside diameter:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2698.JPG)
And made a flange from 1mm brass plate for a light press fit over the step I left on the cylinder end. This will be used to bolt the cross head and piston gland to the cylinder. I also milled a small corner off the port face block to accommodate the flange:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2699.JPG)
Then I fluxed things up and used bits 'n bobs to hold it in place on a fire brick:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2700.JPG)
With a snipped-off bit of 1.6mm silver solder embedded in the flux on the "other side as shown in the last photo" along the cylinder, I heated things with the blow torch from the viewpoint of the photo; not ideal, as the flux closest in view would get direct flame and burn off a bit (hence the reason for the large amount of flux applied!) I also added a dab of solder to the top behind the flange when things were hot; unfortunately a bit too much ::):
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2701.JPG)
Not the neatest job I've done; but that's OK - my defence is "I'm still learning" :D - this was the most complex job I've tried in such a relatively small size.
After a bit of clean-up it looks better; not good; but OK for now:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2702.JPG)
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2704.JPG)
I forgot to include scale; the screw in the last picture is an M2 and the holes in the port face is 1.2mm (0.01")
This might seem like a lot of faffing around... There's several reasons though. I want the cylinder block to have as little metal as possible on it - with a small live steam engine, it's crucial to keep the amount of metal down to a minimum, so that it can heat up quickly, especially with a small boiler. In fact, I'll be removing even more metal off both the cylinder and port block.
As to silver soldering the lot - ordinary electronics soft solder would have done for this job, but some of my future projects will require accurate and neat silver soldering on small complex parts, so I'm just practising!
I wanted to do a bit more today, but it started getting chilly again, so I went inside; hopefully I'll feel better during the week or next weekend.
Regards, Arnold
-
Hang in there Arnold, Hope you feel better soon.
Cracker's coming along nicely. :thumbup: :thumbup:
Ron
-
Arnold,
Looks good to me, :thumbup: a bit of a clean and polish - perfect :clap:
Look after yourself mate, hope you feel better soon :D
:beer:
DaveH
-
Arnold,
I love to see the adaptation of milling cutters. I do it a lot, when necessary. :thumbup:
Don't be too hard on yourself with the outcome. Looks very good to me! :clap: :clap:
Hope you are soon feeling 100% again...
David D
-
Looks good to me to Arnold :thumbup:
Hope you soon start picking up. :headbang:
Stew
-
Ron, Dave, David & Stew; Thanks gents :beer:
:ddb: Feeling better, but had some social commitments that detracted from my shop time - but had a load of good fun with some mates.
This engine is taking on a life of it's own :palm: - I've started to deviate so far from the original plans that I'm pretty much making things up as I'm going along now :dremel:
Yesterday I turned up the crank-side cylinder head. There is enough space to add a pack nut if needed, but I decided to first try without one:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2706.JPG)
The piston followed next. On all the engines I've built so far, I seem to have made the pistons slightly too large, and they all needed a LOT of running to loosen up, so this time I went for 0.01mm under-size rather than my usual 0.005mm as a test; a new piston is easy enough to make. Threaded M2 through the centre and then drilled 2mm to half-depth to guide the connecting rod before parting off:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2707.JPG)
Also made a start on the connecting rod - just some 2mm brazing rod threaded M2 on the end with the tailstock die holder - and a small retaining plate. I was originally going for a full-blown cross-head, but with the cylinder head being fairly thick, I decided to try the engine as-is. The bits I ended up with yesterday:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2708.JPG)
And assembled on the cylinder:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2709.JPG)
Today I started by drilling the right-hand frame for mounting the cylinder block, and also increased the "bearing" hole for the engine in size; I want to add a bit of packing between the engine and the frame to minimise heat transfer from the engine to the frame, and I don't want the bearing part of the engine in contact with the frame:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2710.JPG)
Then I started off on the crank - just a bit of phosphor bronze turned down and parted through a bit to thickness with the 3mm centre hole drilled:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2711.JPG)
On to the rotary table on the mill, and a hole drilled for a press-fit crank pin and whittled away to leave a (to me) pleasing looking web; the original plans don't have a crank web, but it should help to balance the engine a bit as well:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2712.JPG)
Parted off, and it looks fairly presentable:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2713.JPG)
The crank is 4mm thick, so I drilled and tapped it for an M3 grub screw through the web - rather than using threads or retaining compound to fit it to the axle.
I was still busting my head on how to retain the cylinder to the block, and had all kinds of weird and wonderful and complicated schemes floating around my noggin... The block still had to have two holes plugged and that gave me an idea for a simple solution; plug the holes in the block, but leave the plugs sticking out to retain a spring... I couldn't find suitable spring wire, so I used some more brazing rod; it is actually quite springy - and after a flurry of activity pressing in the crank pin, turning up and pressing in the main bearing and a temporary assembly, I had the ugly duckling together - with the idler shaft and gear acting as an impromptu main shaft/flywheel:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2717.JPG)
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2718.JPG)
:palm: Looks horrible :lol:, but I had to give it a test :dremel:
:ddb: Started right up and runs like a champ - without a decent flywheel and at a pressure below what my compressor's gauge can measure :ddb:
Please take a Dramamine before watching the video :coffee:
:D Gave it a blow on breath power, and it runs easily; so after a bit of cosmetic work, I think the engine will do :ddb:
:beer:, Arnold
-
Arnold,
Well that is damn good, :clap: :clap: :clap:
(me thinks your pressure gauge is duff !!) :lol: :lol: :lol:
Really great Arnold, fair zips along, :thumbup: :thumbup: :thumbup:
:beer:
DaveH
-
Give that man a coconut
:clap: :clap: :clap: :clap: :clap: :clap:
I like that retaining spring, neat idea. :thumbup:
Well done
Stew
-
:D :D Yeee HAarrrr! :D :D
Nice one Arnold! Well done...... :clap: :clap:
I can see that grin from here ! :thumbup:
David D
-
Nice going Arnold :clap: :clap: :clap: :clap: :clap: :clap: :thumbup:
Rob
-
Nicely done. :clap: :clap: :clap: :clap: :clap: Like the idea of designing/adapting on the fly.
Abraham
-
Thanks Gents :beer:
Work life keeps interfering with this build :palm: - the week and Saturday was gone before I knew it.
This morning I made the flywheel. Decided to try out my new small lathe even though it still needs a proper bench made for it and bolting down, so I expected some problems.
The first one was the darn "safety" spring-loaded chuck key; it's a royal pain in the butt, and I stopped and gave it a serious look-at with a big hammer and it fell apart:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2720.JPG)
Then I assembled just the shaft with the square drive and handle again; left the rest of the crud off.
I'd already cleaned up the outside of a bit of 32mm cast iron on the Myford, but I faced it and made an undercut on the small lathe:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2721.JPG)
Had quite a bit of bother with chatter; if you look carefully at the sides of the undercut, you'll see. So definitely no more work on the small lathe till I can get it mounted properly and bolted down...
Finished flywheel with a hole drilled and tapped M3 for a grub screw:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2722.JPG)
I previously mentioned that I want to make a spacer to insulate the engine from the chassis, so that was next up - from a bit of plastic sawn from an old printer cover:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2723.JPG)
Then I spent some time making up bits 'n bobs needed to get the chassis to a running condition. Some "tubing" from brass stock to keep the centre gear shaft in position, soldered all the axle bearings to the frames with electronics solder (I learnt from my other loco attempts that bearing retainer comes loose if it gets a bit hot on the frame, and a press fit for the bushes shrinks the inner diameter requiring a lot of manual effort with a reamer to open up back to size), a small spacer for the flywheel to prevent interference with the slightly protruding axles, and finally I silver soldered the pinion gear to the main drive shaft and assembled the lot. View from below:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2727.JPG)
And standing on a bit of track:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2729.JPG)
:) It runs as well - couldn't test it on a full track, but it does (with the "duff" pressure gauge on zero :lol:):
::) Guess I have to work with some copper next:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2730.JPG)
I have to think a bit on the boiler; the plans as-is does not use a regulator or safety valve; it relies on the wobbler cylinder getting blown off the port face if the pressure gets too high in the boiler. The chassis as-is seems extremely lively, so I think I will add a regulator; I like to see slow-running engines. That means adding a safety valve as well - which is a good idea in any case. So I have some calculations and a bit of design to do before getting around to the boiler... Hopefully next weekend.
:beer:, Arnold
-
Arnold,
"I stopped and gave it a serious look-at with a big hammer and it fell apart:" Oh Arnold hang thou head in shame :lol: :lol: :lol:
Really coming along very nicely. :clap: :clap: :clap: What a little runner. :clap: :clap: :clap:
Although looking at the video again, I'm not sure if you are not pushing with that flexible tube. :lol: :lol: :lol:
As usual a great bit of posting, nicely photographed. :thumbup: :thumbup: :thumbup:
Great stuff Arnold.
:beer:
DaveH
-
Cheers Dave :lol: - Must have had a Jeremy Clarkson moment with that hammer :palm:. You got it wrong; I'm _pulling_ it with the tube :lol:
Had a bit 'o time in the shop today :ddb: :ddb:
First off: This is the start of construction of a boiler for the Cracker. Boiler making can and has been a very contentious matter.
I'm by no means an expert on boiler making; this is only my third boiler I'm building, but I have put a lot of effort into researching and trying to understand the subject and the acceptable methods of calculation, construction and testing that goes along with it.
My local government does not have any detailed regulations regarding model boilers, but what I have been able to find mimics the "Three Bar-Litre" rule as used in the UK. This boiler falls well below those limits, and will receive a complete hydraulic test when done; the results of which I'll show.
If any of the MadModder moderators would rather not have me post this, please do remove the posting.
On to the build then...
Some copper work; and at the risk of being classified as a complete lunatic, I actually enjoy machining copper. It has a personality of it's own, so takes a bit of care to work with - and therein lies the challenge and the fun for me. It does not want to be rushed - but dawdle at peril as it will work harden. If it comes off in little curls, things will come out just dandy.
First off, the boiler shell from some 42mm OD/39mm ID copper tube; sawn to near-length, and set up to trim the ends in the lathe. I just lightly chucked the pipe on the outside of the 3-jaw chucks inner jaws, and set up the fixed steady close to the jaws to get it on centre; you can see the ring left on the copper tube from that. Then I moved the steady closer to the tailstock - leaving just enough room to get the carriage in there to clean up the pipe end:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2731.JPG)
Light cuts with a sharp tool, and it was done - for both sides of the pipe:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2732.JPG)
Next, the end plates. The ideal thickness for this boiler would have been 1.4mm - I have 1mm and 2mm thick copper plate, so the thicker one it is. Two bits of copper plate, marked out with circles 10mm in diameter larger than the ID of the copper tube:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2734.JPG)
Off to the band saw, and bits sawn off. When sawing plate, there is always the risk of the sawn-off bits dropping in between the slit on the table and the blade - a sure-fire way to have the excess bit land between blade and bearing or between blade and drive pulley, ending with a snapped blade. ::) Guess how I figured that out sometime ago. So for sawing around roundy bits, I've adapted a method of sawing in at a couple of tangents, but stopping just before breaking through the end on each cut. The blade will push/bend the nearly-sawn off bit away, and the curve can be followed quite closely. With copper it's easy, as it's quite malleable. Before breaking through on the last cut, just stop, wiggle the excess around, and it will snap off, leaving a little tooth that's easy to file off. This shows the excess bits and how things come out:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2735.JPG)
Once completed for both "circles" I just filed off to the line; 5 minutes of well-spent exercise:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2736.JPG)
Completed end-cap discs and a relation to the boiler tube:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2737.JPG)
Some fairly deeply scored rings on the end plates - one on the ID of the boiler tube, the other smaller by the thickness of the plate itself. These are for reference only, but - they need to be well-scored, as the plates will go through several annealing steps:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2738.JPG)
My fire bricks are in an appalling state - I wanted to nip off from work and get some new ones for a change during the week, but just didn't have a chance... Getting ready for the first annealing - with the scribed lines on the bottom, as they are less likely to "disappear" this way:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2739.JPG)
Showed them the Sievert torch with a 20mm nozzle - 20 seconds, and they glowed dull red - here cooling down and black from the heat:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2740.JPG)
A quick dip in water (copper does not need the quick cooling for softening- I was just in a hurry) and much to DaveH's chagrin, the hammer needed to come out again :ddb:
To form the end caps, one needs a former about 0.25mm to 0.5mm smaller than the "ID of the boiler tube less double the thickness of the end plate". I was loathe to turn a good piece of available stock down to size, and in no mind to faff around with turning wood to make a former, so I scratched around my bits 'n bobs and found a CCC (Cheap & Cheerful Chinese) socket that was just on size at 39mm OD. What was nice about it, was that it's corners were nicely rounded over.
I aligned the back of the plate along the earlier scribed rings as best as I could visually with the socket, and using another slightly bigger CCC socket clamped the lot in the vise:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2741.JPG)
Then started hammering the lot down with an ~1kg hammer:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2742.JPG)
Just a couple of whacks at 45 degrees along the circle, turn, more whacks and repeat. No force needed - just a small bend to start off with. This is was actually the hardest part - with each turn here, the alignment has to be checked on the scribed lines after each turn. Super precision is not needed - close will do. With each whack, the copper work hardens, so trying to go all out and just flattening the sides is not even an option.
Once around, the plates are work hardened, so anneal again and repeat - next three photos shows the progress before annealing and repeating each time (Well, You DO like pictures don't you :D):
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2743.JPG)
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2744.JPG)
::) (there was one hammer blow completely out of order on the left-hand plate)
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2745.JPG)
With the final round of hammering, I offset the front socket downward so that I could get close to the edges to really get things tight:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2746.JPG)
Turn everything a bit, more hammering and repeat. Takes a while, but it's a great stress relief!
The end cap on the barrel; it's nearly a fit, and if I could be bothered earlier to turn a proper former to size, it would have just slipped in. In fact, a good whack with a hammer would make it stick in the boiler barrel, but that's not good enough - it needs to be a bit under size to allow for proper silver solder penetration later on:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2747.JPG)
After minimal work on the lathe - just a skim over the edge and turning the ragged end down to size, I ended up with the completed end caps:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2750.JPG)
Back to the boiler tube, and some near Arnoldidiot proof layout and marking:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2751.JPG)
A while ago I bought a step drill, as other boiler builders were singing and dancing it's virtues for making nice round holes in copper. Well, I'm now singing and dancing along :ddb: - none of the "rounded triangular" holes from normal drills here; just a nice and round hole :) :):
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2752.JPG)
The step drill goes up in 2mm increments, but I needed a 15mm hole in the barrel, so I used the step drill to go to 14mm, and then the boring head to open up the hole to 15mm:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2753.JPG)
The end caps needed some holes poked in them; one of them just a 15mm hole for the flue tube, and the other another 8mm hole for the steam take-off/regulator mounting.
I used the tooling plate in the mill for drilling the holes, but that precluded the use of the step drill as it could not drill deep enough (well, at least not without poking a hole into the tooling plate ::))
Seeing as I had two end caps to machine, I used two cap screws as locators, clamped the first end cap down and drilled it 6mm:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2754.JPG)
Then opened the hole successively to 10mm and 14mm with end mills:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2755.JPG)
And bored it out to 15mm with the boring head. A completely boring post by now...:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2756.JPG)
The second end cap received the exact same treatment, except that it had an additional 8mm hole poked in it:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2757.JPG)
After cutting some 15mm pipe to length,I ended up with a few coppery bits for today:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2758.JPG)
Some Scotch Brite cleaned the bits up nicely, so I decided against pickling over night. I still need to make the needed bushes anyway.
:beer:, Arnold
-
Lovely clean copper work Arnold :clap: :clap: :clap: :clap: :clap: :clap:
And well shown to boot :thumbup: :thumbup: :thumbup: :thumbup: :thumbup: :thumbup:
Stew
-
Thanks Stew :beer:
Not a lot done today ::) - just made the bushes and filler cap from phosphor bronze.
The safety and steam take-off bushes are threaded M6x0.5. The filler bush is threaded M10x1.25; M10x1 would have been better, but I have not found taps and dies for this yet.
I also hollowed out the filler cap as far as I could to get rid of excess mass that would need heating up and made it look approximately like a steam dome. In fact, I'm seriously contemplating using the filler cap as an actual steam dome; the regulator bush on the backhead is not far above the maximum water line, and if the loco lurches a bit, water is bound to get into the main steam line. It's a fairly simple job to add a dry pipe that will extend part-way up the steam dome, and it won't hamper filling too much...
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2759.JPG)
I still have to decide what I want the chimney to look like...:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2760.JPG)
:beer:, Arnold
-
Arnold,
Don’t worry about the boiler. In the UK all they say is go and see “your boiler inspector”. You ain’t got one Arnold.
Nicely documented and made. As usual well photographed, I see you made good use of your tooling jig. :thumbup:
This is a very nice posting, makes me want to make one. :clap: :clap: :clap: We could have a race!
It’s coming on, looking good. :D :D :D
DaveH
-
Fantastic I just love it. :clap: :clap:
-
Dave, Benny, :beer: - thanks gents.
Dave, I might not have a boiler inspector, but knowing the "system" here in Namibia, one might be "invented" at any time :lol: - besides, I'd rather have things up to standard, especially since I'm showing it publicly and I do value my own and other people's body parts :thumbup:.
I love that tooling plate; I can kick myself for not making it earlier in my short machining "career" - and there will definitely be more of them made :ddb:
Do you have tracks - or are you going to fit rubber wheels to yours ? :poke: - :D - we can definitely have a race :ddb:
Well, a coolish day here in Windhoek today, and nothing heats up a cold shop like a big torch :) - so I started soldering things together.
First off, some flux around the bushings, and left the flux to dry out a bit while I bent some rings out of some 40% silver solder. I have two types of silver solder - this 40% cadmium free, and some 40% that contains cadmium. The non-cadmium needs a higher temperature to melt and flows less easily into joints. It is also good to note that if solder containing cadmium is used, there are potential health risks associated with it - so I tend to use those very sparingly - only if I need to fix up an already-soldered joint or if I really need the slightly lower melting point:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2763.JPG)
I also brushed some flux around the holes on the inside of the barrel - I just use a small paintbrush for this:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2762.JPG)
Then I used a permanent marker to draw "rings" around the holes - this is just some intentional contamination to prevent solder from flowing all over the show. One can use a soft lead pencil or error correction fluid ("Tippex") for this as well. I pushed the bushes into their holes. The rings of solder will actually go on the inside of the barrel:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2764.JPG)
The assembly was then put down on a fire brick resting on the bushes, and I added the silver solder rings on the inside, with a bit more flux on the rings. Then I closed up the one side and one end with fire bricks standing vertically. The front side was left open, as that's where I would be applying the heat (right at the very bottom), and the left side so that I could look into the barrel and check on the progress:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2765.JPG)
I heated that lot up playing the flame along the bottom - it needs to get dull red for this solder to flow.
The first couple of times two years ago that I tried silver soldering, I had a lot of problems. The biggest one was thinking the job was a bad 'un when the flux turned black and stopping the heat at that point. Once I discovered that the flux I have turns black, and with a bit more heat goes crystal clear and the work needs to glow dull red, things suddenly came together.
Once I could see from the open end that the solder had flowed, I left it to cool down a bit, then turned it around to check the result:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2767.JPG)
While it might look like a dog's breakfast, it is actually a good 'un; the yellowish coloured rings are where the flux did it's job of cleaning and protecting the metal from the flame, and the pinkish-orangey shiny stuff is actually flux that floated to the surface. There is a nice fillet of silver solder all round the base of the bushes that was wicked through.
Into a bit of pickle it went; I use Citric Acid which is available in the cake baking supplies section of the grocer just down the road. It's relatively cheap, non-toxic (in fact, I mix the powder with water and just have a quick taste now-and-then till it tastes sour enough) and can safely and environmentally friendly be disposed of down the drain:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2768.JPG)
While that lot was pickling, I turned up a new bush for the backhead. In the last post I said I'll add a dry-pipe, so I needed a longer bush tapped M6x0.5 with a short section in the back just drilled out to 3.2mm for the thin copper pipe I have:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2769.JPG)
Ready to solder the bit of copper pipe on it:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2770.JPG)
The pipe still needs to be bent to fit up into the middle of the steam dome and trimmed to length.
The end caps are a loose fit in the barrel to allow flux and solder to wick in, but that presents a couple of problems when trying to solder things together, as nothing wants to stay put, and one have to resort to jigs or something to keep things in place.
I chose to resort to the "or something" bit :ddb:
I used an automatic centre punch at a slight angle to pop some evenly spaced dimples around the circumference of each end cap - the slight angle causes the soft malleable copper to raise a nice burr on one side of each punch mark:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2771.JPG)
Now it doesn't just fall down the barrel any more - it has to be lightly tapped into place, and it will leave an even gap right around for the flux and solder to wick in:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2772.JPG)
More rings of solder; one to fit the barrel and one to fit the flue, and a slight flare added to the flue by tapping it on the end with an old lathe centre I have lying around:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2773.JPG)
A bit of fluxing later - flux brushed around the inside the barrel where the end cap will go, around the end of the flue (with it's ring of solder already in place) and around the outside and inside the flue hole of the end cap:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2774.JPG)
Then I tapped the end cap gently into place in the barrel, added the flue, and ring of solder. I used the other end cap partly pushed in on the bottom (leaving it sticking out so I could get a grip to remove it again) to keep the flue in it's correct position, and supported the bottom end cap in a bit of excess copper tube sawn off the barrel initially. Some fire bricks were stood on end to help retain and localise heat:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2775.JPG)
I carefully brushed some more flux over the ring of solder, and heated the lot slowly at first; the flux I brushed on the ring in the barrel was quite wet, and I wanted it to dry out without bubbling all over the show. Once it dried out and stopped bubbling, I turned open the tap on the torch and played the flame just below the bottom of the end cap, moving it around the outside of the barrel. The fire bricks really help here by deflecting the flame around the back of the barrel and heating it there as well. Once the solder around the barrel flowed, I kept the heat on a bit longer and the solder around the flue followed suit.
Once again, the top of the job looks a bit unimpressive - I would have liked a nice even fillet of solder around the barrel rim, but there's a couple of bits that look like there's not enough solder in there. The fillet around the flue is quite satisfactory:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2777.JPG)
The back side is a different story though :ddb: - There's a nice even fillet of solder around both the flue and the barrel rim, indicating that the solder flowed between the bits as I had intended, and the joints are good 'uns :D.:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2778.JPG)
Apologies for the crappy photo; it's a bit difficult to get the light to catch the inside of the barrel and get the camera at an appropriate angle and focus "down there" :doh:
I'll use a bit of the other silver solder I have to fill in the top rim fillet - if it is really needed.
I put that lot back in the pickle to overnight and called it a day; hopefully I'll get some more done tomorrow.
:beer:, Arnold
-
Nice bit of boiler smithing their Arnold :thumbup: :headbang:
Stew
-
Very nicely done Arnold! :clap: :clap: :thumbup:
David D
-
Way to go Arnold :clap: :clap: :clap:
-
Stew, David & Benni - thanks gents :beer:
Well, a mixed bag of results for today...
After leaving the lot in the pickle overnight, I started fluxing up the last bits for assembly:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2784.JPG)
Once again, rings of solder and some extra flux:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2785.JPG)
Showed it the torch, and got a horrible result. Some flux had run off the side and some silver solder followed that. Flux had also flown across nearly the entire end cap, so solder everywhere :bang: :bang:
And worst of all, if you look carefully at the bit where the flue comes through the end cap, there's no fillet - in fact it looks like there's no solder in the joint :bang: :bang::
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2786.JPG)
:doh: That'll teach me to remember to draw on anti-flux lines and not to use so much flux...
I plonked the boiler back in the pickle for a couple of minutes to get the top cleaned up, and used another ring of solder and a more conservative amount of flux, and ended up with a good clean fillet around the flue.
The boiler was then put back in the pickle to clean up properly.
I made a quick T-piece to fit the boiler back head bush and my pressure gauge and hydraulic pump:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2787.JPG)
Then collected together all the bits needed for the pressure test - pump, gauge, some ptfe tape, a bung for the safety bush, the T-piece, and of course the boiler which cleaned up nicely:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2788.JPG)
Some ptfe tape on the bung and T-piece:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2789.JPG)
All connected up and the boiler filled to the brim with water, before screwing in the bung:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2790.JPG)
An overview of the layout - ready for pressure:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2791.JPG)
The boiler maximum pressure as I calculated it would be 40 psi. This means the hydraulic test must be done to 80 psi - which is 551 kPa.
The first test is to take it up to pressure, and then release it. The second test is to take it to pressure and make sure that it will retain pressure for at least 20 minutes.
The pump is very quick - just two and a half strokes on the first test, and I'd overshot the pressure already, but that's ok:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2792.JPG)
I released the pressure by unscrewing the filler cap - you can see how little water came out - just a tiny puddle:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2793.JPG)
Back up to pressure again, and once again I overshot the needed pressure:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2794.JPG)
I left it and spent some "office" time to remotely start the month-end run at the company I work for. Took about 30 minutes, and this is what I found when I got back to the boiler:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2795.JPG)
:ddb: :ddb: I'ts a good 'un - it's just a pity I ruined the last bit of soldering.
:beer:, Arnold
-
Well done that man
:clap: :clap: :clap: :clap: :clap: :clap: :clap:
Stew
-
Arnold,
Fabulous tutorial on making a boiler, - you made it look easy. :bow: :bow: :bow: (But I don’t think it is)
The boiler is very nicely made – looks great. :thumbup: :thumbup: :thumbup:
Really good informative post, and well photographed. :clap: :clap: :clap:
Thanks Arnold for taking the time to show it.
:beer:
DaveH
-
I really need to practice silver soldering....... :wack:
Very nicely done, and shown Arnold! :clap: :clap: :thumbup:
David D
-
Thanks Stew :beer: I still have a lot to learn about boiler making though. There are hopefully some more complex ones in my future; this one is just practising the basics.
Cheers Dave :beer: - I hope I didn't show too much, but rather too much including the little mishaps than too little. It's not really difficult, but it does take a bit of thinking through and planning.
David, Thank you :beer:. I'm enjoying the silver soldering; it does seem to take a bit of practice. Not with heating things, but in the preparation. The hardest part for me is figuring out just how much flux to use...
This weekend I'm having to divide time between the shop and my day job... Just part of the fun of working in IT I guess; some things need to be done when other people are sleeping and having weekends :lol:
Did manage to steal a bit of time in the shop though, and started on the steam regulator - another deviation from the original Cracker plans as it's not included there.
I simply "stole" Dave Watkins's design for Idris's (http://www.davewatkins.pwp.blueyonder.co.uk/16mm%20railway/steam.htm) regulator and adapted it on the go. Not many photos, as it was all just basic lathe work with 8mm hex brass rod. One exception is the spindle, which was turned from some 4mm stainless steel rod. That was just turned down to 2mm for about 16mm, then to 3mm for another 10mm and threaded M3 with a tailstock die holder, and a taper turned toward the collet chuck to _just_ before it would part off:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2803.JPG)
That left a nice concentric spindle. The taper was then polished up slightly with some emery, and the very last bit turned off to part the spindle from the stock.
A very out-of-focus photo of the bits made today:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2804.JPG)
From left to right: 1) Regulator body with M6x0.5 nose and drilled through 2.5mm and then opened up and threaded M6x0.5, 2) the spindle, 3) M6x0.5 lock nut, 4) bush threaded M6x0.5 right through on the outside and drilled 2.1mm through on the inside and the tapped M3 for the spindle part-way through, and 5) pack nut for the spindle. The bottom 2 pieces are the steam take-off and nut - both threaded m6x0.5, with the take-off an nut designed to clamp down some 3.2mm copper pipe with a silver-soldered on ferrule.
After taking the last photo, I silver soldered the take-off to the regulator body, and dumped it in the pickle to clean up overnight. Hopefully I'll find a couple of minutes tomorrow to finish the regulator.
As an aside... I don't like gardening very much, but I do like plants and animals. The plants in my garden are mostly drought-resistant cacti and aloe species; they don't need much attention and like our weather. In fact, they are MUCH better at predicting weather than the Met office. On the way to the shop this afternoon, I spotted a welcome sight; one aloe had started pushing it's flowers, and that means we only have another one or two cold spells before our short spring and then summer is on us :D - that's good for shop time:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2797.JPG)
:beer:, Arnold
-
Arnold,
Nicely done, ideal size for your new lathe. :poke:
The photo makes them appear to float :bugeye:
Coming on, won't be long now. :clap:
:beer:
DaveH
-
:beer:, Thanks Dave
:doh: I really must get that small lathe sorted ::) - it's just standing there doing nothing.
:lol: Hoptical disillusion; the parts are lying on my "ultra-high-precision surface plate" - aka thick sheet of safety glass... If the focus is out, things "float".
And no progress to report on the cracker; I finally got some shop time today and squandered it on this lot :doh: :
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2817.JPG)
:beer:, Arnold
-
Arnold,
I missed you, thought you had left us :(
Nice to see you're back :D
Well it does look nice, what is it for. :scratch:
:beer:
DaveH
-
And no progress to report on the cracker; I finally got some shop time today and squandered it on this lot :doh: :
:beer:, Arnold
Well squandered Arnold! :clap: :thumbup:
But..... Worrisit? :scratch:
David D
-
Arnold,
I missed you, thought you had left us :(
Nice to see you're back :D
Well it does look nice, what is it for. :scratch:
:beer:
DaveH
Same her
What is it for :scratch: :scratch: :scratch: :scratch:
Stew
-
:beer: Cheers Gents
Dave, I'm like weed (no, NOT the Dutch/Hippie type! - the unwanted stuff you get in the garden :lol:) - You'll have one hell of a time trying to get rid of me as :nrocks: :D :D :D
:doh: Been working like a dog at my office job for the last 3 weeks; sometimes up to 16 hours a day, so shop was a tad out - nothing like a tired mind in the shop to sacrifice body parts to the machines...
:lol: :lol: As to the mystery pieces, it's an "Executive Toy" for my decidedly non-executive office desk :lol: :lol: - it's a finger engine in progress with a clutch system to allow it to free wheel. Just working from odds 'n ends I have lying around, and already the clutch mechanism needs to be redone as it's not as reliable as I'd like it. Not really up to my personal standard of appearance, but it's for some quick gratification, so I'll call it a bit "rustic" and carry on. Friday's a public holiday here in Namibia and I bluntly told my bosses I'm taking my long weekend, so I'll try and finish it on Friday, and use the rest of the weekend on the Cracker again.
:beer:, Arnold
-
Well, squandered more time on the finger engine, and it resulted in this:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2837.JPG)
On to the Cracker then :D - not much but some done...
Used a bit of bronze to start the smokebox "door" from:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2840.JPG)
A bit of a waste of this bronze, but it's easier to find locally than brass is - and approximately the same price!
Turned it down for a light push fit in the boiler smokebox, and hollowed it out quite a bit. Then flipped it and started turning the outside detail for the smokebox. First just some free-hand turning, juggling the apron and cross slide; my ball turner can't get that close to the chuck:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2841.JPG)
Followed by a file (VERY carefully, as those chuck jaws were close!) and some emery:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2843.JPG)
Then a hole in the centre - tapped M4 to fit a handle; I must still decide whether I want a lever or a wheel style. Also milled out clearance for the chimney on the back side:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2844.JPG)
It looks OK on the boiler :D :
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2845.JPG)
And that's it for now. I'll see if I can get small bits done during the week; next weekend I have to work at the office :doh:
:beer:, Arnold
(Edited for some gross spelling mistakes!)
-
Arnold, that's a cracking looking little cracker there. :D :D :D :D
Very nice
Ron
-
Good work :thumbup:
-
Arnold,
Quite a little violent finger engine, like the 'free wheel'. :thumbup: :thumbup: :thumbup:
Cracker is coming along very good, the dome looks good. :thumbup: :clap:
:beer:
DaveH
-
Ron, Benni, Dave - thanks Gents :beer:
:D Sometimes a work week that's gone badly makes for a great weekend... I had some crises thrown at me during the week at the office, with a result that I could not get around to do the prep that was needed for this weekend's work, so I got shop time :ddb:
First order of the day was to start on the safety valve. I turned a bit of 8mm hex brass down to 6mm and threaded it M6x0.5 to fit the treads in the boiler bushes. I still have not been able to find a decent M6x0.5 die nut, so I just used the "thread cleaning" nut I have supported by one of my tailstock die holders to thread the workpiece:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2848.JPG)
Parted off to a suitable length, I chucked it up in reverse, and started drilling... First 2mm right through, then 5.5mm to a suitable depth for threading M6x0.5 - which was duly threaded. Then I used a 5mm end mill to flatten out the bottom of the hole:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2849.JPG)
A bit more drilling, this time 3mm diameter and about 3mm below the bottom of the flat section. This is a lot of faffing around - I'm out of 3mm stainless steel balls to use in the valve, so now it's on to a pop-style with O-ring. That'll teach me to run out of balls :lol: The (nearly) finished safety valve body on the boiler, with the 5mm flat barely visible around the 3mm centre hole:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2850.JPG)
Next the adjusting nut; a bit of brass round turned down to 6mm, and a 1mm hole poked through the centre:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2851.JPG)
Then threaded M6x0.5 on the outside and parted part-way, and off to the rotary table on the mill to add some 1.5mm slots around the outside; these will allow steam past the adjusting nut:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2853.JPG)
After some more lathe work to turn the valve itself I had all the bits together for the safety valve; the O ring from a kit, the "brass" pin (actually coated soft steel) from a packet of Cheap 'n Cheerful Chinese design-your-own jewellery stuff, and the spring from a cheap disposable lighter:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2854.JPG)
A stainless or bronze spring would be better, but I couldn't find any; older style tire valves had some nice springs, but the new ones are not suitable... Fortunately, if the spring corrodes from steam vapour, it will reduce the safety valve's operating pressure.
Then I soldered the pin to the valve and assembled the lot after trimming a section of spring off. A quick check with the compressor showed that the valve works nicely, which I hadn't expected on my first try with this type of valve; it was easy to adjust to open at 35 psi and repeatedly re-sealed properly without leaking. Assembled it looks like this; it still needs final setting while on steam, but the adjustment range is good so I added a little loop to the top of the valve spindle to make it easier to test manually that it's not sticking:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2855.JPG)
The hex valve body was definitely not pleasing on the eye, so I made up a quick mandrel and turned down the body a bit:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2856.JPG)
On to a bit of planning... It was high time I sorted out what I wanted to do about the smokestack and cab. This engine will be used quite often to "play" with and show off, and while it is roughly based on a real model, it's more of a fun toy than a model, and it should look the part. I scrounged around a bit and found the extra pipe reducer I bought "in case" when I built the burner for the Little Blazer; it looks quite pleasing as a smoke stack... Some recycled ciggy packs to mock up a cab - I'm not quite happy with that yet, but to get a rough idea. I'll only finish the design of the cab once I finished the rest and have the loco running, as I don't want the gas tank and regulator difficult to get to; this engine must be easy to run:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2857.JPG)
At least, having decided on the smokestack, I set up the boring head in the mill and faced off the end of the copper fitting to conform to the boiler outside diameter - clamped down using a tightish-fitting bit of bar in the bore to prevent the milling vice from flattening it:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2858.JPG)
While I had the boring head set up and to the correct dimension, I messed around with some hardwood - that will become the boiler mountings:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2859.JPG)
Utter laziness - milling down wood on the mill :doh: :lol: :lol: :lol: :
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2860.JPG)
How about a reprieve then? - I used my mitre saw to saw off the needed bits:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2861.JPG)
Ended up with these - there's a bit of wood that splintered out on the one, and I hadn't noticed until too late :doh: :
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2862.JPG)
With the stack soldered on (I used electronics solder for that), things are starting to look up:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2863.JPG)
Time to start messing (albeit very carefully and safely!) with the gas supply system... I haven't been able to find jets as specified locally, and the only gas filler valves I can find comes from these cheap pencil torches:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2865.JPG)
If only the body where the filler screws into were brass! - Alas, it is aluminium and useless. The filler uses a thread for which I don't have taps - measured across the thread it's 5.4mm. The pitch appears to be 0.5mm which is fine. This leads me to believe this is M5.5x0.5 ??? - so I'll have to make a tap. I'll play around with the torch first; maybe it's jet will work as well, which will save me the bother of having to make my own or wait for months for delivery from overseas.
:beer:, Arnold
-
Nice I just love this project :drool:
-
Looking real well Arnold
You've given me some inspiration to get to work on my loco, I've stripped it down and bin correcting some of the faults that I know its got.
Stew
-
Arnold,
Great stuff, looking really good, coming along nicely. :clap: :clap: :clap:
Nicely photographed and posted again. :thumbup:
:beer:
DaveH
-
Benni, Stew & Dave - Thanks Gents :beer:
Stew, I'd love to see you continuing with your loco :thumbup:
Sunday I spent fixing things around the house, but this weekend we changed to Summer time, and that always leave me feeling like spending time in the shop after work, so this afternoon I did some testing with the pencil torch and bits 'n bobs, not expecting much success.
This is the jet end of the pencil torch, with the burner removed:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2870.JPG)
It looks like there's a tiny bit of aluminium foil stuck in there with the jet hole punched in it. The end fits nicely in a bit of 8mm copper pipe though.
I cut a bit of 8mm copper pipe, made an aluminium ring for it to fit in the boiler flue, and crimped the end shut with the vise. Then I used a junior hacksaw to saw some grooves in it, and drilled a 2mm air hole right through both sides of the pipe at a point just deep enough to allow the jet end of the torch to be pressed in. I also used a bit of the same copper tube I made the boiler flue from and cut that to the same length as the flue. Having read up on other people's attempts at making these poker burners, I fully expected to have to spend a lot of time getting it going, so instead of starting outside of the "flue", I decided to start right from the beginning with the burner in the flue (or simulated flue in this case). These are the bits I started off with; very crude, but I didn't expect too much for a start:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2874.JPG)
And all assembled:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2873.JPG)
then I clamped the "flue" in the vice and started trying to light up... The first couple of attempts resulted in some big whooshes out the end of the flue, so I decided the gas/air mix was a bit rich, and I started drilling out the air holes in front of the jet - 0.5mm each time. When the holes were 3mm, the flame flashed back into the tube and started burning at the burner inside the tube. I even had a bit of control over it by regulating the torch, though the flames were a bit "off-colour". So I drilled it out to 3.5mm, and ended up with this with the torch set to a very low setting:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2872.JPG)
A nice bright blue flame with barely a hiss of gas, that I could regulate nicely with the torch valve to full-open and a blue flame licking out of the end of the flue tube - indicating a nice gas/air mixture; I wasn't about to poke my camera in front of that though!
In fact, I'm pleasantly surprised at how well it works and how quickly I got a satisfactory result - so I guess I'll have to go and grab a handful of these torches for their jets and filler valves while the getting's good...
It remains to be seen how it will operate in the boiler with the smokebox and smokestack though; I might have to open the air hole a bit more - or make a ring (like on gas lanterns) to restrict the airflow slightly to adjust the mixture.
:beer:, Arnold
-
Arnold,
You really do come up with some ingenious ideas, I would have never thought of using a pencil torch. :scratch:
Everything is coming together nicely. :D
Nicely posted Arnold - a real pleasure looking and reading your posts. :D
:beer:
DaveH
-
:beer: - Thanks Dave. That pencil torch was driving me up the wall anyway, so it's good to find a better use for it.
Some days are just a pleasure in the shop; today was one of those golden days, with everything just going right :ddb:
First thing up was the tap needed for threading for the filler valve... I could have single-point turned the thread, but a tap would be convenient, as I have two other boilers that I want to build gas tanks for, and some future projects will also require it. From other posts and documentation, I know the "standard" Ronson style filler valve uses an M4.5x0.5 thread, but the one in the donor pencil torches is definitely M5.5x0.5. No matter; I don't have a tap for either anyway.
I chucked up a bit of 6mm oil hardening silver steel, and turned it down to 5.5mm for a length, added a run-out groove with the parting tool, a step on the front that's exactly 5mm diameter, and a gentle taper just by eye using the topslide. The tap will be used on through-holes, so there's no need to make it in the shape of a plug tap:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2877.JPG)
Then I set about carefully honing my "small" 60 degree threading toolbit to a really nice sharp tip on an oilstone - using a "fishtail" gauge to make sure I didn't go out of kilter on the angle. A 0.5mm pitch is a relatively fine thread; the total infeed needed is only 0.25mm / just under 10 thou, and the tool must be really sharp to cut accurately:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2878.JPG)
I used a rod chucked in the tailstock to set the tool squarely, once again using the fishtail to check:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2879.JPG)
Then I spent a good half an hour setting up the ML7's change wheels for 0.5mm pitch, and thoroughly cleaned each and every gear tooth and the lathe's leadscrew with a toothbrush before giving it all an even coat of oil. Fine threads don't like gunk in the drivetrain. My lathe does not have zero-able dials on it; so I found the total depth of thread reference reading by feeding in till the tool _just_ touched the 5mm section. I wound the cross slide out and dialled in an ~2 thou cut for the first pass:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2880.JPG)
Three more passes at 2 thou infeed each followed - with a good amount of cutting fluid applied for each pass. This sounds like very little, but with the extremely sharp tip needed on the tool, anything more might easily chip off the tip. On a coarser thread this would not matter much, but on a fine thread, that would mean re-doing everything; it's difficult to pick up a thread properly if one have to re-grind the cutting tool, and all dial readings go out as well. Fine successive cuts also helps to make a really smooth thread in my limited experience, and that's exactly what I want from a tap. My original depth reading was between 45 and 46 thou on the handwheel - and as close as I could judge it at about 45.75 thou - but that already left a scratch, so for the last two passes I went to 45.5 thou; one to cut and one to finish. This is what the result looked like:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2881.JPG)
It's always nice to have a reference to check with; in this case the body of the donor pencil torch, and it screwed on smoothly right away - but more importantly with no free play in the thread at all - just what I wanted:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2882.JPG)
:lol: Can anybody tell I love doing single point threading on the lathe ? :lol: - I'll stop boring you now and get on with things.
I used this setup to mill the tap flutes - it's nice to have a dividing head that can plonk into the mill vise in just seconds:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2883.JPG)
A bad photo follows; focus was on the chuck and not on the face of the workpiece :doh: - I milled in the flutes - with the milling cutter cutting about 0.1 mm below the centre line. This provides some relief on the tap's flutes for cutting, and also allows a bit of sharpening after it's been hardened:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2884.JPG)
After milling out the flutes, I coated the workpiece liberally in some semi-dried-out dishwashing liquid, and shoved it on a dirty and well-used bit of firebrick that I don't care much about:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2885.JPG)
The soap makes it easier to get a bit of shine back on the workpiece after hardening it - and more importantly, it provides a bit of protection to the delicate threads by forming a kind of coating when heating things up.
I took that lot, a bucket of used motor oil I have hanging around, a pair of pliers, a fire extinguisher, a leather welding glove and a small blowtorch outside to the driveway leading to my shop. There I set up things so that I would be up-wind of any fumes, with the fire extinguisher behind me - ready to grab on-the-run.
Why all this boo-hah ? - well, I can't get my hands on water hardening silver steel (drill rod) - so I have to use oil hardening. I do have some air hardening silver steel, but that always warps, so is pretty much useless for a job like this. Hardening the workpiece means heating it till it's bright red, and then dunking it in the oil to cool rapidly. That produces a good bit of potentially highly flammable/explosive smoke - so safety is paramount. It's not nice getting burnt; I know very well from some non-shop but first-hand (well, both of them in fact ::) ) experience.
No photos of the process; that's a distraction that I'm not comfortable with, and besides, things get a bit hectic; there's simply no time to take a piccie :). It goes like this (I'm right-handed):
* Welding glove on right hand, and make sure there are no open or smouldering flames about; not even a pipe/cigarette; this is a no-smoking zone...
* Start torch and with left hand blow flame length-wise across workpiece, moving torch around to get as even heating as possible. Uneven heating will cause warping.
* With pliers in gloved right hand, rotate workpiece around a bit while heating.
* Next lot must be done very quickly...
* Once workpiece is bright red hot, turn off torch - make sure it's turned off, pick up workpiece with pliers, take a deep breath and hold, then dunk workpiece vertically into the oil at arm's length (with gloved hand). Once it's submerged, swirl it around a bit. There will be a lot of smoke coming off for a couple of seconds. When the smoke stops, keep the workpiece swirling under the oil for another 20 second or so - it is still very hot when the smoke stops. Oh, and it's safe to start breathing when you're sure you're not going to breathe in any of the oil fumes. If anything lights up and start burning, drop everything, make a dash away, grab the fire extinguisher "en passant" (that's why it must be behind you when you start), then at a safe distance turn back and decide what needs to be done.
* Wipe excess oil of workpiece, and use a file you're not particularly fond of and try to file a bit off the workpiece in a place where it does not matter; I tested with the edge of a half-round file in the thread run-out section of the tap. If the file just skids over without actually filing out a bit, you've got success. If it files a bit out, you get to re-do the whole process and you have to be a bit quicker and/or heat the workpiece a bit more than on the first try. The file skidding off (and actually getting blunted in the process) is an indication that the workpiece hardened correctly.
::) If you have access to water hardening silver steel/drill rod - you can fairly safely skip a lot of the previous write-up; just heat it bright red, vertically dunk in water (careful: the steam coming off can scald you) and swirl. A fire extinguisher behind you is still a good idea though; one never knows :thumbup:
Now came the hard bit; tempering the tap. As-hardened previously, it is like glass; it will easily shatter or break if dropped or bent. The tempering process adds a bit of toughness back to it, at the sacrifice of some of it's hardness. Tempering means bringing it back up to a certain temperature and quenching again - there's a lot of references available that mentions different temperatures and their associated colours. There's fancy ways with precision equipment to do all of this, but I don't have any of those, so I went by the book according to older engineering books. I don't foresee this tap getting used in anything but brass, or maybe bronze, so it does not need to be all that tough - in other words, just lightly tempered. If its hard, it'll stay sharper for longer. So I used a bit of Scotch-Brite to shine up as much of the tap tip and shank as I could do easily (this is where that soap I put on earlier really helps). Then, by just heating the shank with a small flame (NOT on the tapping teeth itself) I could let the heat run through for what I think is the so-called "light straw" colour. I still used too big a flame, so the heat transferred a bit rapidly, and I was in a near panic to quench it again - this time in water; it does not seem to make too much of a difference if the tempering is done in water compared to oil, as long as the heat is stopped. In this photo you can see where I stopped it; the tip of the tap and the teeth are yellowish compared to the paper in the background. The rest is dark blue to black - meaning tough but not hard. You can click on the photo for a larger image:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2886.JPG) (http://www.nam-engineering.com/cm/displayimage.php?pid=3400&fullsize=1)
I used a diamond needle file to clean up the flute's cutting faces, and ended up with this:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2888.JPG)
Not pretty, but hopefully effective.
I had to try the tap out, so I turned up a brass bush to silver solder in the gas tank - drilled through at 5mm (tapping size), and 6.5mm to a depth of 2mm to mimic the original pocket on the donor torch. Then I tried the tap; just chucked up in the tailstock chuck:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2890.JPG)
:ddb: :ddb: It works a treat; it actually tapped easier than my shop bought M6x0.5mm taps; no squeaks from the brass, and barely any effort needed to turn the collet chuck - I'm right chuffed with the result :D :D
And the proof of the pudding; the filler valve screws into the bush easily and accurately:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2892.JPG)
I ended up making a couple of more bits, and ended with this lot for today:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2895.JPG)
It will go together like so:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2896.JPG)
The copper fitting is an ACR grade pipe coupler; rated at a much higher pressure than the original plans call for. I'll have to do a bit more single-point turning to make an adapter to match up with my pressure gauge to pressure-test the gas tank once soldered up. I need to make the regulator first as well,as it's body must be silver soldered to the tank as well.
:beer:, Arnold
-
Looking good Arnold that tap looks very well done.
:clap: :clap: :clap: :clap: :clap:
Stew
-
...... "I'm right chuffed with the result" ........ :D :D
So yer should be! What a good day's work. With a satisfying, accurate outcome. :)
Well done Arnold! I'm really enjoying this gently developing saga...... :clap: :clap: :thumbup:
David D
-
Thanks for a very thourough expination on treadcutting and making a tap, it is filed for future refferance. :bow: :bow: :bow:
:beer:
Abraham
-
Well done Arnold. Very nice write up also.
It seems I learn some thing new each time I check in. :D :D
Ron
-
:beer: Many thanks Gents.
Today was a bit quiet in the shop... Not much to show as the bit I did was pretty straight forward lathe work.
I started off on the gas regulator body; it needed a couple of different holes drilled into it, with the very last one a very deep 1mm hole - here I have only about 4mm of the drill bit clamped up in the tailstock drill chuck, and the chuck was run in till the jaws very nearly touched the workpiece:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2899.JPG)
Then I started on the regulator needle; it's supposed to be made from 3mm rod, but I only had some 4mm stainless kicking around, so I turned it down in stages moving the work further out of the chuck between each stage. First the needle tip, then moved out and turned down and threaded M3:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2900.JPG)
After this photo, there were two more stages of turning down to 3mm to get the correct length.
Then I made the pack nut, and called it a day for today; just 2 hours in the shop, but I had some other things to do. The finished lot:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2901.JPG)
:beer:, Arnold
-
Very cool work as usual Arnold!!!
Will be following this build to the end!
Is the stoep track ready yet??
Andrew
-
Arnold,
Well you certainly took off this weekend, started with that nicely made tap, finished with an equally nice gas regulator. :thumbup: :clap:
A real pleasure as always Arnold – thanks :clap: :clap: :clap:
:beer:
DaveH
-
Nice going Arnold :bow: :bow: :bow: :bow: :bow:
Looks like you had a cracking couple of shifts in the shop :dremel: ,,,,,,,,,,,,, must be the warmer weather :lol: :lol: :lol:
Rob
-
Thanks Andrew :beer: - the Stoep Track is laid and ready to use; just needs some final fixings and a bit of scenery... I left the track laying loose through the winter to see what happened at the rail joiners; I expected that the big temperature differences we get here (from 0C in the night to as high as 25C that same day) might wreak havoc with the track shrinking and expanding, and it did. So there's no way I can actually fix the track down; it'll have to stay loose to allow for the temperature expansions, so I'll most likely just dump some fine gravel down over it as ballast to limit movement while running trains.
:beer: Thanks Dave. Like I said, one of those golden shop sessions :ddb:
Rob, cheers mate :beer: - :lol: - We're back to high 20s and low 30s, so I've started to thaw a bit :lol: - Definitely nicer in the shop now :thumbup:
Today's little bit...
The gas tank body had to have a hole drilled through for the regulator body - so I clamped it up in the mill using the end caps to prevent the copper tube from collapsing, and a nice thick bit of cardboard to soak up the tiny differences in size between the caps and the pipe. Then I just plunged an 8mm end mill trough; no need to struggle with drill bits wandering all over the show:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2905.JPG)
On to a bit of silver soldering... I fluxed the bits where needed while assembling, and used a fire brick to hold things down. I set the job slightly over the edge of the bottom fire brick on purpose - using the broken indent on the brick to good effect. A small ring of silver solder was used around the filler bush right in the bottom; for the rest I decided to stick-feed the solder rather than use rings, as it would have been a complex job trying to make up rings for that lot:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2906.JPG)
I left the overhang at the bottom to use the fact that silver solder follows the flame's heat; as there was only a partial ring of solder around the bush, it would melt and follow the flame, thus coating and filling the entire joint. For the cap itself, and the regulator body, I used the flame around the outside and fed the silver solder in on the inside - also using the flame to draw solder into the joints. Around the regulator body, the solder flowed out nicely to the outside, as the brass bits sticking out into the flame got really nice and hot.
As I was in a bit of a hurry, I gave the workpiece just a very quick pickle, and used a scouring pad to clean up a ring on the inside where the bottom end cap needed to get soldered in. For the bottom cap, I used a ring of solder - bent so that it was a spring fit in the body, and that the cap would push it into the body when assembling:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2908.JPG)
Then I fluxed up the ring of solder, and around the outside of the end cap, assembled, turned upside down from the photo, and soldered the lot together. This was a bit more difficult; I couldn't see what the solder was doing and when it melted, so I had to keep a careful eye out for when the solder flowed trough to the outside - and then had to use the flame to make it follow around the joint.
Gas tank all assembled after more pickle and a bit of rubbing with Scotch-brite:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2909.JPG)
It's not pressure tested yet... I had to dig and scratch to find the recommended pressure to test it to; eventually I had a look at the different LP gas cylinders I have around, and nearly all of them was tested to 3000kpa (around 435psi). :palm: The highest-reading pressure gauge I have is only 1000kpa - so I'll have to invest in another pressure gauge; can only get that on Monday. Oh well, there's still many bits left to make, and then there's the little matter of a breath-powered Elmer's #46 Coomber Rotary that I have to make before middle October...
:beer:, Arnold
-
Some more little bits out of the way... When an engine nears the running stage there's always a lot of tiny time-consuming bits to make :lol:
First up was the smokebox door handle. I went for a round one - just shaped a bit of brass by eye and threaded it to fit the threads I made in the smokebox door:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2912.JPG)
Then milled some 2mm cut-outs in it on the RT on the mill:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2913.JPG)
These were followed with a 2mm drill trough each cut-out.
Then I parted it off on the lathe; half-way down first, then used a small file to round the corners, then finished the parting. As I needed to work on the parted face a bit, I located one of those short bits of off-cut that never seems to be useful as it's too short to really use...:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2914.JPG)
I chucked the off-cut in the lathe and drilled and tapped it to match the handle-in-making:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2915.JPG)
Just screwed the handle into it for further work:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2916.JPG)
Then I hollowed out the front a bit with drills and used a riffler file to try and get a curve in there; not too successful, and not quite what I had in mind, but it'll do for now:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2917.JPG)
Next up, a bit of 4.7mm thick brass flat marked out and drilled 1.6mm through the width, two 1.6mm holes furthest away through the flat side, and a 2mm and 2.5mm hole respectively nearer in view through the flat side:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2918.JPG)
All the 1.6mm holes will be tapped 2mm.
A couple of cuts with a 0.5mm slitting saw:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2919.JPG)
And some tapping, 2mm clearance drill through one side of the top of each bit, and a bit of filing later, I had the bodies of the regulator handles:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2920.JPG)
Both needed, well, "handles" - so I fashioned some up in the lathe; just by eye; removing most of the material with the toolbits and using a small file to finish off the contours:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2921.JPG)
To the left, you can see that I used the file to nearly part off the handle; after this photo I just snapped it off by hand and filed the pointy left-over end down.
Then I had a look-see how things fit together so far:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2922.JPG)
:bang: The "Cab" is extremely busy, and everything is in something else's way... I Guess that's what happens when you don't follow plans strictly :lol:
I mulled things over a bit... I want both the steam and gas regulator controls easily accessible, and it must be easy to get to the gas filler valve for a refill; this loco will be run often, so ease-of-use and ease-of maintenance gets priority over aesthetics. I worked out that if I extended the steam regulator handle to the back of the engine, and turned the gas tank 90 degrees from the previous photo so that its regulator handle is at the side of the loco, all controls including the gas filler would be easy to reach, and the pipe work would be minimalist, making things easy to take apart for maintenance.
Extending the steam regulator left me two choices; I could make a complete new needle valve with a longer shaft, or make an extension piece. I'm lazy, so I opted for the extension piece :lol:
The easiest and cleanest-looking way to fit it to the existing is by using a steel pin through both; that can then be removed easily if needed, so I turned up the extension from some brass rod, stuck the valve in the end I drilled to fit it, and cross-drilled the lot for a 1mm pin:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2923.JPG)
A final check, and things look OK - the piping should be fairly easy to do now - both for gas and steam:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2924.JPG)
:beer:, Arnold
-
This is so very intressting project, I just love it. :) :clap: :clap:
-
Arnold,
Some very nice silver soldering on that gas tank - very nice gas tank. :clap:
Coming along very nicely, nicely posted as usual. :thumbup:
It is really going to look something special this cracker :clap: :clap: :clap:
:beer:
DaveH
-
I love the way you think through, and develop ways around problems Arnold! :thumbup:
Love how this is developing...... :clap: :clap: :D
David D
-
Benni, Dave, David - Many thanks Gents :beer:
I had two days of leave from work; unfortunately not for shop, but to attend to some matters relating to government red tape...
At least I bought a good quality pressure gauge yesterday - at very good discount from one of my regular suppliers. I'm finding that a lot of the suppliers that up to a year or so ago treated me a bit reservedly has nicely thawed; where initially discount and a bit of natter was taboo, that's run of the mill now. Got the gauge for less than half the shelf price!
This afternoon I got a bit of shop time.
Started by turning down and single-point threading a bit of 8mm hex brass to the same dimensions and thread as the gas filler valve:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2925.JPG)
Then parted off a section, flipped it in the chuck, drilled through at 2mm and then drilled and tapped it M6x0.5 to fit existing adapters for my pressure testing kit. Ended up with this:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2928.JPG)
It needed an O ring - so I added that:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2929.JPG)
Then I set up for testing - replacing my 1000kpa gauge with the new 4000kpa gauge. The gas tank was filled with water - though not completely. It is so small that a bit of air in it is needed to allow at least some form of control from the pump; if there is a leak it won't be too much:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2930.JPG)
On the first pressure-up I took it to 3000kpa, but the pressure dropped rapidly. On checking, I found water leaking around the valve spindle packing, so I just snuck up the packing nut a bit more.
Next pressure up:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2931.JPG)
I left it sitting for 20 minutes, and came back to find the pressure had dropped slightly:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2932.JPG)
The gas tank was bone dry, so I looked around to find the leak; i eventually found it on the regulator adapter where a droplet of water had formed on the connection - but all-in-all, I think it's safe to say the gas tank is up to scratch :ddb: :ddb:
As a final test, I screwed in the gas filler and filled the tank with gas, then plonked it in the water to see if there was any gas escaping by looking for bubbles:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2933.JPG)
No bubbles appeared... I also tested the regulator while under water; it is easy to control and get varying amounts of gas escaping.
Having done that lot, I treated myself :D :D :
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2934.JPG)
:beer:, Arnold
-
Good going with the pressure test Arnold I reckon you'll have this beauty in steam before long.
Stew
-
Arnold,
Well everything seem good there, I do like that pump you have. :thumbup: :thumbup: :thumbup:
It's not going to be long now before it is full steam ahead. :D :D :D
:beer:
DaveH
-
:bow: :bow: :bow: :bow: :bow: nice one Arnold :thumbup:
Rob
-
I just discovered your thread and it is great! As a beginner I really appreciate your time and trouble to show how you have done things. This will definetly be book marked for future reference.
-
Stew, thanks :beer:, I hope to have it at least running by the end of the weekend; all the little nitty gritty things left to do :lol:
Cheers Dave :beer: - though the pump was a bit over-sized for this job... I need to make one with a smaller piston for future gas tank tests; both for better control and to use less force; I recon 3000kpa is about max for this one.
:beer: Rob, thanks mate. Will be a little slow for the next couple of days though.
Thanks danstir4 :beer: - it's a pleasure and I'm pleased you find it useful. Just be open-minded though; I'm also pretty much a beginner, and some of the things I show might not necessarily be the best way to go about things - and definitely not the only way of doing it :thumbup:. And welcome to MadModder !
I have a visitor for the rest of the week, so I doubt if much more will get done before the weekend, but I did manage to sneak in a couple of minutes after work today.
Started on some of the steam pipe work; the first thing I need are some "olives" that will get soldered to 1/8" pipe. Here I'm turning up the first one - just some 5mm hex brass turned down to 4.2mm OD to fit inside a normal M5 thread, then parted off part-way to just below 3.3mm diameter, center drilled with a 2mm center drill, and ready to be drilled through with a 3.3mm drill:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2936.JPG)
Doing it this way leaves the olive sitting on the drill bit when drilling through with a minimum of burrs.
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2937.JPG)
I have some 6mm hex brass on order, but for now just made up some on the end of an 8mm hex bar:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2938.JPG)
Then followed the same procedure as with the olive to turn up a nut after drilling and tapping it for M5 - with a final drill-through at 3.3mm:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2939.JPG)
The results of today's bit - thebigger nut on the left was already made along with the steam regulator - the nut on the right and the two olives was made today. Cutting thin copper pipe is a problem, but a small rotary cutter like the one shown works a heck of a lot better than a hacksaw:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2941.JPG)
That's it for now; I think the next update will have to wait for the weekend.
:beer:, Arnold
-
Hi Arnold, that is looking good, and I like the idea of the center pops, I've left dog hair in a joint with the expectation of it burning out as the solder fills up the gap, but that sounds more positive and cleaner. I've also had the issue of wanting a reamed hole and not having the reamer, taking the on size drill bit, and stoning a radius on the cutting edge corner of each flute, perhaps half a mm or so, will let the bit go in the next size smaller hole, and if the radius is clean and has clearance, it will give as good a finish as a reamer will.
It's nice to see the respective parts put together even if only trial fit, it gives me a chance to get an idea of what it will look like in the end. I'm really looking forward to seeing it steam. :jaw: :beer: Cheers, mad jack
-
Arnold,
Nicely done, :thumbup: getting close now to steam :clap: :clap: :clap:
:beer:
DaveH
-
Jack, Dave, Thanks Gents :beer:
Yesterday was a dud; I had to spend the entire day at the office, so no work done...
This morning I started assembling things...
Some PTFE plumbers' tape rolled into a string:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2942.JPG)
Then wrapped around the needle of the steam regulator to form packing under the pack nut:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2943.JPG)
I used a bit of thin wire to determine the length and shape for the main steam line; it's easier to bend and cut a bit of wire to shape than a piece of copper pipe:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2944.JPG)
Main steam pipe bent to shape and the ferrules soldered on - I used electronics solder as it is soft enough to give a good seal, and there would not be a way for the pipe to come loose in the position it is installed:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2945.JPG)
A bit untidy - I used a file afterward to remove some of the excess solder.
The completed main steam line:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2946.JPG)
Next I cut the jet end off the donor pencil torch using the small pipe cutter shown earlier:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2947.JPG)
And turned up and soldered on a suitable pipe fitting:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2948.JPG)
Then did the final assembly to get the loco to a ready-to-run state:
(http://www.nam-engineering.com/cm/albums/userpics/10004/normal_IMG_2950.JPG)
I moved needed bits to the stoep track, oiled the engine and bearings, and filled the gas tank and boiler. The first fire-up didn't go too well. The green pipe really didn't like the heat at the jet side of the pipe, so I shut everything down, beat a hasty retreat back to the shop and made a copper gas pipe as well.
The next fire up went well, and I got this result:
There were still a couple of steam leaks - around the regulator valve and at the engine which I fixed up, and then settled back for some more running:
With the leaks fixed the regulator works nicely - and the gas system also works well; it raises steam in 4 minutes from a cold boiler & water and then with the burner turned down a bit it does lap after lap - after about 10 laps the gas tank runs empty - a refill, and both water and gas runs out together later. I spent a couple of hours just refilling it and letting it run - until eventually all my refill gas ran out :ddb: :ddb: :ddb:
Now it just needs a cab, a good tidy-up and a paint job :D :D
:beer:, Arnold
-
Wow very nice. You have done an exellent work here. :clap: :clap: :clap:
I have to ask "I used electronics solder" I don't understand that, what do you mean or what it is? :doh:
-
Hi saw
Usual resin cored solder used for electronic stuff.
Often 60/40 or thereabouts ..
BC
-
That's great Arnold!! :D
What a lovely little runner! :clap: :clap:
I'm sitting here with a big grin. Very pleased for you...... :thumbup:
David D
-
Great stuff, Arnold. Congratulations on a job well done and beautifully presented.
-
Thanks for answering me "Usual resin cored solder used for electronic stuff.
Often 60/40 or thereabouts " I am propebly dum but is not the plomming silver looded (sorry for misspelling) :scratch:
-
Well done :clap: :clap: on a great runner.
:beer:
Abraham
-
That's a good'un!!
Just love it!!
Saw; lödtenn för elektronik, finns på Clas Olsson eller Kjell & Co! Vanlig j-a lödtenn... Antagligen tunnaste varianten. Och det är inte alltid så lätt med främmande språk... :scratch:
Kjelle
-
Kjelle:Tack nej fackutrycken är svåra trots att jag försöker med Google Översätt.
Is there a reason why you are not using silver looding? :bang:
-
:bow: :bow: :bow: :bow: :bow: Your the man :headbang: :headbang: :headbang: :headbang:
Great job Arnold ,,,,,,,,,,,,,,,,, just love the desert track layout :lol: :lol: :lol: :lol: needs a camel or two :D
Rob
-
YAHOOO
ITS A RUNNER
Great job Arnold wonderful bit of work
:clap: :clap: :clap: :clap: :clap: :clap:
Stew
-
An other runner Arnold!!! :thumbup: :thumbup: :thumbup: Well done.
Ron
-
Many thanks Benni, David, Marv, Abraham & Kjelle- :beer: - I'm right happy with the loco, though it still needs a way to go to complete it.
Benni, like BC said, I used 60/40 "electronics" solder - 60% lead 40% tin with a resin core. I have a couple of rolls of lead-based solder like this, newer electronics solder appears to use something to substitute the lead for health reasons, and my rolls of solder is about 20 years old, so still have the real lead in it. I'm definitely not conversant in Swedish, but I think I catch the drift from Kjelle and yourself. As far as I know, there is solder available with just a bit of silver in it (4% I think) with a low melting temperature - somewhere between the electronics solder and what is normally called "silver solder" which I used to make the boiler with. I think this is what you are referring to as "plomming silver looded" which I interpret as "plumbing silver leaded". That would work just fine in this application as well. :thumbup: Don't worry about spelling - as long as you can get the idea across, it's fine. If I've not interpreted correctly, please do say so :thumbup:
Rob, Cheers mate; - the track needs a bit of sand though :lol: - looks too much like a concrete jungle right now :lol: I'll be sure to buy a packet of "ship of the desert" Tabs to get some camels for the scenery :lol: :lol:
Thanks very much Stew :beer: much appreciated. Now I have to build a Coomber before I finish this one...
:beer:, Arnold
-
Thanks Arnold of course it should be "plumbing silver leaded" sorry :(
Your'e locomotiv is outstanding, beutifull build and you have an teknik to build that I enver you.
You are the master. :bow: :bow: :bow:
-
Arnold - that's a beaut of a runner you've got there! I was worried that she might fly off the track at the first corner, she was up to such a good clip, and sounds spot-on. She's really living up to the name "Cracker" :thumbup:
A quick side-note about solder:
- Olde Worlde electronics & plumbing solder were 60% tin, 40% lead, or very close to. This mixture melts readily, and re-melts readily too. You can still buy it (in the UK at least), e.g from Farnell.
- New electronics (and maybe plumbing?) solder is a mixture of tin & copper - 99.3% tin, 0.7% copper according to the reel I have here. I believe some lead-free solders also contain silver. Lead-free generally melts at a higher temperature than the old lead/tin mix, and needs different fluxes.
The old stuff (& rosin flux, which is also pretty much considered to be evil these days) smells much better than the new stuff, and is easier to use IMHO.
-
Good job!
-
Ron, Thanks very much :beer: - I missed your post!
Thanks once again Benni :beer: - Don't worry about your spelling :thumbup: - I really don't think I'm a master though; anybody can do the same; it just requires a bit of effort and persistence :thumbup:
Cheers Ade :beer: - :palm: I got the tin/lead wrong way around... :lol: - I don't know what the new solder and flux smells like, but I do know the old solder well; repaired and built many a circuit in years gone by. The smell does get to one after an all-nighter re-soldering about 140 RS232 connectors to change them from 25 pin to 9 pin though :lol:
Thanks kvom :beer:
:beer:, Arnold
-
Arnold,
Smashing :thumbup: :clap:
Runs very nice, great post Arnold :bow: :bow: :bow:
:beer:
DaveH