Another Paddleducks build log

[spuddevans]

Thanks Darren, but I can't claim any credit for the split bush idea, it was straight out of Bog's plans. I do admit that out of not having a vice stop that is small enough for the job I did decide to use the split collet for holding the flanges in the mill, and it worked out ok.

Tim

[Rob.Wilson]

Hi Tim

Great thread   , I like your spilt collet , are you going to mill the flats on the flanges ?   you could turn  them oval with a quick jig

Cheers Rob

Edit  done some quick pic's

[spuddevans]

are you going to mill the flats on the flanges ?   you could turn  them oval with a quick jig

Thanks Rob, yes the plans do call for milling flats on the flanges, the method shown in the plans is to put 2 2mm rods thru the 2mm holes and use them resting on the top of the vice to get the flats in line with the screw holes.

I like the idea of making them oval, but I dont think it would suit this engine so I will file that idea away for future reference 


Tim

[spuddevans]

 

I forgot to post up some pics of my pipe bender.

John (Bogs) kindly sent me some plans for this bender when I mentioned that I would like to try using bent pipes instead of using a machined stand-off, and for the last few weeks I've been working on and off ( more off than on ) on building it.

I have stuck loosely to the plans in some areas, and not at all in others due to not having hardly any raw stock that was called for in the plans. I didnt take any "in-progress" pics, sorry.

Here's some pics for your enjoyment,









One handy hint I can pass on is with regard to turning the brass forming wheels. I ground up a form tool to a rough outline of a 4mm half circle, but slightly smaller. Now here's the handy hint, it only works for 4mm tubing/pipe, but to finish off the round grooves in the forming wheels to a perfect finish, get a hold of a chainsaw sharpening file, they are round and are 4mm in diameter. Stick one in a file handle and then it just takes a few strokes while the lathe is running slow to finish off the grooves. I also made 2 slightly different diameter sections on each wheel to give a slightly smaller radius of bend to choose from. ( if I was to make it again I would make the difference greater )

I also fabricated up the main handle from 2 pieces of 3mm steel and a lump of cast iron. I tried to silver solder it all together, but not having made a hearth for silver soldering it took about 10 mins, blasting it with the torch. I wasnt sure that the silver solder had taken, so I drilled and tapped M5 to re-enforce it ( so far it has held without putting in the M5 bolts ).

I also did not bother making the rest of the clamp as the plans called for. They call for taking a 2" length of 1" square steel bar and machining and turning most of it away. Not having any steel square bar, nor was I looking forward to machining all that away too. Standing looking at the plans for a while it dawned on me that there is no real requirement to make a clamp for it, a standard engineers clamp will do the job just as well, and I didnt have to spend any time making it.

I dont anticipate having to use this bending tool too often so I think just using an engineers clamp will do me just fine.


Tim

[spuddevans]

So I got a little more progress made today. I milled the flats on the flanges using 2 2mm drillbits to position them in the vice.

That done I got started on bending some tubing. At this point I realised that the radius that I was getting with my bender was not tight enough, so I decided to reduce the diameter of the smaller section of the bending wheels by 1.5mm depth ( 3mm total reduction ), this proved to be just right so it was on to making the bent pipes and silver soldering them on to the flanges.

The silver soldering went ok, there was a 2 flanges that I had to redo, I dont think that I got the joint clean enough on those 2. I did find it amazing just how soft the copper tubing gets just after soldering, it's very easy to make the straight sections wavy by just handling it

Then after dropping all the flanges into the pickle for about 20 mins I fished them out and gave them all a gentle clean with a grubby cloth to get rid of the remaining flux, I finished off by trimming the tubing sticking through the flanges with a hacksaw, filed them, and finally a quick rub on some 360grit w&d on a flat surface to polish the faces of the flanges flat.

Anyhoo, here's the obligatory pic of the finished flanges with tubes,



Next will be onto the steam-control valve, that's bound to test me as it seems that you have to be very accurate with making the spool. I'm pretty good at making one part to an accurate size, but getting both the valve-control-block and the spool accurately made will test me a bit more.


Tim

[spuddevans]

Today I realised that I have been a bit skimpy on the pictures, so when I went out to the workshop I was determined to take more pics, cos   


A few days ago I had a few mins and so dug through my little pile of materials and found a bit of brass bar, round bar as I didnt have any square brass bar of the right size.





Then today I stuck the cut-off piece in the mill and started to turn ( he he he ) it into a square.





After a little while I ended up with this.





But as you see, the end mill left a rather rough finish, so I left a little extra "meat" on the brass block and then switched over to the mini-flycutter.





Once all edges were silky-smooth and sized to requirement I set the block on it's smoothest face and flycut the opposite face, then flipped it and repeated the process to size the block to thickness.







Once the block was sized I set out to mark up the edges for drilling all the various steam holes. Then I set up a vice-stop.

One thing I have discovered when using a vice stop ( that you guys probably already knew ) is that it seems to be better to set up the vice stop before putting the workpiece in the vice, otherwise it is very easy to not get the vice stop right up against the workpiece. Whereas when you put the stop in first you slide the workpiece up against it just like you would do it on subsequent operations, the results ( for me anyway ) turn out more consistant ( making sure to clean the vice area when re-positioning workpieces )

Anyway, back on topic, I set up the vice-stop and then put the block into the vice against the stop. Then using an edge finder I set up for drilling the centre holes and then centre drilled all 4 edges.



And then drilled



and then drilled the outer steam holes by positioning the drill over one outer site and then switched the block around to drill the other outer steam hole on that edge.





Then finally I drilled the 1.6mm holes for tapping M2 for attaching the flanges for intake and exhaust using the same method.

Then I started to tap the M2 holes.




And wouldn't you know it, on the last hole the tap broke off while backing it out 


Now I have to source some alum and then dissolve it out.


Anyway, at that point I called it a day and came back inside.

Tim

[Brass_Machine]

Wow Tim... those are some pictures! Very very clear and crisp.


Nice work too! 

Eric

[spuddevans]

Wow Tim... those are some pictures! Very very clear and crisp.


Nice work too! 

Eric

Thanks Eric 

I sometimes wonder why I take so many photos as they really do highlight all the machining marks and scratches on every surface, but then I think to myself "how cool would it be if I became some sort of bling-meister and was able to polish up all these pieces at the end of the build to contrast with these pics" and then I come back to reality

I do hope to really clean up all the parts when I get this running, I even have this crazy notion of getting some sort of electro-plating setup to plate some of the parts.


Tim

[Rob.Wilson]

Hi Tim

Have you seen some of those home plating kits you can get ?  ,,,,,,,,,cracking photos , sorry to here about the snapped tap .

Regards Rob

[spuddevans]

Thanks Rob 

Have you seen some of those home plating kits you can get ? 

Yea, I've seen a few but the Caswell system seems to be very popular and probably the route I will try. Because most of the parts on my build are brass it means that I can plate nearly all the different kinds of electro-plate directly onto the parts without having to 1st of all plate with a base coat of copper ( or at least that is my poorly-educated understanding of it )


Tim

[Rob.Wilson]

Hi Tim

The Caswell system ? please tell more 

Regards Rob

[spuddevans]

The Caswell system ? please tell more

Caswell's UK dealer

Caswell's USA site that has loads of info and examples.


Theres' loads of info especially on the USA site.


Tim

[SAM in LA]

Sure is expensive.

[Rob.Wilson]

Cheers for the link Tim .

Looks good , i will  have to look into it .

Thanks Rob

[CrewCab]

Rob, I'm pretty sure Caswell's will be at the Harrogate show in May, are you going this year.

CC

[spuddevans]

So I got an afternoon in the 'shop today, I started on drilling the larger hole for the actual spool valve. ( sorry no pics of this as I got a little carried away after finally getting back into the workshop )

So this is all the machining processes on the main valve block done, I blocked up the 2 little holes that transfer the steam to the ports on the engine and silver soldered them, then filed and sanded smooth.

The valve block,






Then it was on to setting up for soldering the four flanged pipes that I bent earlier, into the valve block. After a little shortening on a couple of pieces of pipe I bolted the whole to-be-soldered assembly to the main cylinder-block assembly




The eagle-eyed of you will notice that on that pic there are only 2 joints with rings of silver solder on, the reason is that I ended up re-soldering a couple of times. The 1st time two joints must not have been clean enough, and so that picture is the setup for the 1st redo.


And this is how I actually heated this 1st redo





To keep some heat off the 2 good joints I put a 1/4" piece of Ali' to deflect some heat. However, I proved to be too cautious about not re-melting the 2 good joints as when I quenched this I discovered one of the freshly soldered joints had not taken.

 

So, once again I cleaned up and fluxed and soldered the one remaining joint, and thank goodness it worked.


Then it was on to the actual spool valve, I chucked up some 12mm brass rod in the ER32 chuck in the lathe


and had at it until it looked a bit like this




Parted off and lapped to the bore of the valve block with T-cut



And here's both items ( the valve block assembly has only been pickling for 20 mins here, still a fair bit of cleaning up to do )




And that's all I got done today, next will be making the front and back covers for the valve block, then it will be milling the slots in the valve spool, and then it'll be getting really close to getting it running 


Tim

[madjackghengis]

I have finally got round to making a start on my next ( Yep, I've caught it...  ) project, and while tempted to do a Rocking engine, I had to stick with with my initial plan of building Bog's Paddleducks engine.

So I had previously got some materials gathered for this build, and not having any cast iron at all, but having a brass block that was itching to be reduced to a nice cylinder-shaped block, I decided to use brass for the cylinder.

Here is the raw brass block, the other dimensions are 25mm thick and 50mm high.



I then used my very expensive marking dye system and used my vernier caliper to mark out a rough shape to then transfer to my very expensive bandsaw (my right arm  )



So I next ground up a tiny toolsteel for my tiny flycutter as per the Bogstandard curved profile that I read about on a thread here somewhere. This is my second attempt at grinding the curved shaped flycutter, I have a larger flycutter that doesnt cut as well as this latest attempt, practice I guess 


So with this newly ground up tool I am totally impressed with it. The finish on brass is soo silky smooth!!! Compare it to using a end-mill and there is just no contest. I also learnt that my X2's Z axis is made out of a very tough but flexible form of spagetti. I am intending on re-inforcing the upright column, but in the meantime I have to be mindful of taking lighter cuts.



I have an even smaller flycutter, they're so dinky.

By the way, is there an accepted method of working out what speed to set the mill at for flycutting? ( the smaller flycutter seemed happy to run faster)

So after squaring and sizing the 4 sides I then squared off the 2 ends with a 4-flute mill.



It's amazing how the little brass chippings/shavings get everywhere (especially down the neck of my teeshirt, and they are pretty hot too  ) My workbench was (and still is) covered with a golden snowstorm.



I then had to smooth the 2 ends with some 360grit wet+dry placed on a granite plate to try and get them to match the smooth flycutter-ed surfaces.

And here it is, the first part made to size (well within 0.02mm on 2 dimensions and dead on the 3rd )



That's all I got done today, not much to see so far, but it's good to be back on an engine project and I cant wait to get back into the workshop to crack on with it.


Tim


Edit: If you want to see larger versions of the pictures of this build click here

Hi Tim,  with regards to speed and flycutters, it's all about surface feet per minute, or the metric equivalent.  Just look up the diameter of the cut, at the edge, the material you are cutting, and the appropriate cutting speed in your Machinery's Handbook or equivalent shop data to get the feeds and speeds appropriate, and the best finish.  Nice start on another interesting engine, brass always looks good.  Mad Jack

[spuddevans]

Thanks for the info regarding speeds for flycutting Mad Jack


I got a bit more done today on the flanges for the valve body. I started up by cutting off a chunk of 22mm brass bar,



then I turned down a 10mm spigot 7mm long,



Then reversed it in the ER32 collet chuck



And turned a 1mm deep spigot sized to match the bore of the Valve body.



Then, leaving 3mm thickness on the flange I was parting off, I parted it off. Then it was on to the top flange. I turned another 1mm deep spigot to fit the bore, drilled a 4mm hole all the way through, then bored a 6mm wide by 0.9mm ( ok, mine turned out to be 0.88mm but lets not split hairs ) recess which is for a sealing O-ring.


Here are the pair of flanges ready to have the mounting holes transferred from the main valve block, then drilled and the back flange tapped, that will be the next job.



the other side showing the recess



That's all for today,

Tim

[Ray]

Tim, I notice you and others use a radial surface on your flycutter tool.  Does it have any angles (rake) or both sides and top just flat?  I tried tosharpen my cutter like that, all flat sides and top.  It just thuds over the surface leaving  big dents.  Any tips or advise will be appreciated.   Very nice build.  Ray

[spuddevans]

Hi Ray, I sharpen my flycutter using the method that Bog's showed in This thread

It does seem that the rake is important to getting a good finish and having a reasonably durable edge for the tool. My 1st attempts at grinding a flycutter did not work too good, but by sticking at it and taking note of what others said, and especially that post of Bog's, I managed to get going ok. Now I just wipe the face of the tool on an oilstone a few times before using it and that seems to keep it sharp.

I find that I can get a lovely silky smooth finish on both brass and Ali', I've had some mixed experiences with cast iron, but I think I was trying to run the spindle speed far too fast. That's what I love about flycutting brass, it accepts a higher speed.


Hope this helps,


Tim

[Ray]

Thank you very much Tim.  I read the thread and looked at the pics and drawings very carefully.Appreciate your assistance and Bogs for his thread.  Ray

[spuddevans]

I got a couple more hours in the workshop today. I started by finishing off the holes in the flanges that I had spot-drilled last time, and tapping the rear flange. Then it came onto sizing the valve itself. I started by just fitting the valve into the valve body and fitting both front and rear flanges to see how much was to be removed from the valve spool. Notice the little gap between the body and the front flange.





Then it was over to the lathe to skim off a shallow cut ( about half the size of the above gap ), then re-assemble. Still not there, so back onto the lathe, another skim, assemble, getting closer. This went on for about 8 times before it got very close. The reason for doing this in tiny stages is that if you cut too much off you have to re-make the spool, and I thought that taking small cuts and trying to fit, then taking another small cut, etc etc, would be quicker than having to remake the spool valve from scratch.

Anyway, as the plans suggest, when the valve got very close I switched from cutting with a hss tool to using a piece of 360 grit W&D backed by a flat piece of metal, to just sneak closer to the right size. The right size was when the spool could just rotate with the flanges bolted tight together.

Once that was done it was time to mill the slots in the spool valve, 3mm wide and 3mm deep slots.





Then the only part left to make is a little handle for the spool valve. I drilled a 4mm hole in some Hex and then I chucked it in the 3jaw, rounded a section and then filed the end round ( this was a lot quicker using files than setting up my ball turner ), then I set a 5-10 degree on the compound and turned a tapered section.




Then I cross drilled a 2.1mm hole for the tightening screw, cut a slot through to the 4mm hole and then counter bored a 12mm bore in one side of the 4mm hole to allow the handle to fit closer to the valve body. Then tapped the 2.1mm hole M2.5 and bored out the opposite side to 2.5mm.





Everything put together.





And I think that is all of the parts made for this engine 

Next I will be assembling it all together and hopefully seeing if it works ( then we'll see how many parts have to be remade  )


Tim

[NickG]

Looks lovely that valve and handle, very authentic.

 

Nick

[Brass_Machine]

Tim,

Looks good! 

Eric

[spuddevans]

Well I have spent a slightly frustrating afternoon on this engine. I built up the engine into 2 sections, top and bottom, the bottom holding the crankshaft assembly and the top that had everything else. Then I timed the eccentrics with the crankwebs as per the plans and then assembled the top and bottom sections together.

Feeling very excited I hooked up the little air compressor and fired it up.....




FFFFFFFFFFFFFSssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss



Lots of air escaping around the spool valve straight out the exhaust pipe. The only thing I can cling some hope on is that I havent put the O-ring in yet, but I think that is just vain hope. I reckon I will have to remake the spool valve.

Undeterred I decided to press on and just hook up the air to one cylinder at a time just to see if I could get it to kick over. I then found that all those parts that I made that fitted together firmly add up to an engine that is nigh on impossible to turn over by hand, let alone by air

I had to remove one of the piston valves and ream the packing nut, and also polish the shaft of the piston valve, then put it back together. Then I tried again but no joy. Again broke various parts down to free them and adjust, re-assemble and try again.

This cycle repeated itself for about 1.5hrs until I started to get close to finding out how many times it would bounce so I gave up for today. At the last go it did give a good kick and tried to go, but it was binding up so it wouldnt give a full turn. I finished by removing the top from the bottom in order to make sure that the crankshaft assembly will spin freely by itself, then I'll work on getting the valves and cylinders working free as well, then re-assemble the 2 parts and see if it'll run.

Oh, and I've got to sort out the reversing valve, as I mentioned before, in almost all positions it was leaking ( more like gushing ) air straight out of the exhaust, so the remake looks like it is on the cards.


So, no video of it running yet, but give me some time and hopfully I will get something up for you to see, either an engine running or an engine flying. ( through the air towards a wall-shaped object )

Tim