Elmers #25, my first engine project

[spuddevans]

Well after being advised to try a simple wobbler engine as my 1st project I've decided on Elmers #25. The fun part has been converting the imperial to metric measurements       

So I dug up a little slab of 6mm ali plate and hacked off a piece approx the size I needed. Then came the 1st issue to overcome, as the biggest milling cutter I have at present is 6mm I felt it was unwise to size the frame piece in one pass. So I took off my milling vice and decided to clamp the frame to the top of a 3-2-1 block that was squared up to the table, and use the side of my 4 flute mill to size.


Once sized up I then marked up for drilling,


After boring all the holes I tapped the intake M4, I ment to tap it M3 but messed up the drilling  so I had to enlarge to M4 as I dont have a M3.5 tap.


So after drilling and tapping all the relevent holes the frame was done, or at least it was machined, I have to clean it up and polish it up a bit.

I then moved on to the cylinder. I had a piece of 19mm square brass bar. This presented a new challenge, I dont have a fly cutter or a milling cutter over 6mm. So how can I machine this 19mm square bar to 17mm x 15mm, and get a reasonable finish?

Up steps the 4 jaw chuck.


I remember reading somewhere about how to turn a cube using a lathe, and I just stole borrowed the idea, and what do you know, it worked!!

So I now have the cylinder blank sized and ready to bore, and that's as far as I got.


However, in the process of sizing on the lathe I found out that getting a nice finish relies on smooth advancement of the cross-slide. ( yea, I know that you all know this, but it was new to me ) I found a bit of a cheats way of taking the monotony out of winding it back and forth, and getting a better finish. I just attached my cordless drill to the capscrew holding the handle on the cross-slide and just ran it on a low speed. Got a far better finish than I could've got otherwise. You just have to be careful to keep the drill in line as best as poss.


Anyway, that's the 1st part of my little adventure into building a wobbler, stay tuned for irregular updates   

Tim

[spuddevans]

Oops, forgot to post a pic of the completed (but desperately needing cleaning up) frame and the prepared cylinder blank.





Tim

ps, if you want to see larger versions of the pics click www.velvet-art.co.uk/elmers

[sbwhart]

Well done Tim

 

Great use of the old 1*2*3 blocks and like the drill power feed.

I can tell already this engine will be a runner.

Stew

[spuddevans]

Thanks Stew, I have to say that I'm barely started on this and I am completely hooked 

I can tell already this engine will be a runner.

(Strokes white cat in a very Bond-bad-guy-esque style) "It will run, oh yes, it will run". Even if I have to make and then re-make every single part several times, I'm determined to make it run.

The plans say it should run on 5-10psi, so I should be ok as my compressor will put out 115 psi  "Oh yes, it wiill run!!"


Tim

[bogstandard]

Tim,

I thought you were an absolute beginner.

Methinks you are telling a few porkies. Some of the techniques and clamping procedures you used are usually the sign of someone with some experience behind them.

Very nicely done, using techniques on a lathe, to obtain what really should have been done on a mill for ease of making.

Bogs

[sbwhart]

The plans say it should run on 5-10psi, so I should be ok as my compressor will put out 115 psi  "Oh yes, it wiill run!!"


Tim

At 115 psi it'll take off 

Stew

[spuddevans]

Tim,

I thought you were an absolute beginner.

Methinks you are telling a few porkies. Some of the techniques and clamping procedures you used are usually the sign of someone with some experience behind them.

I'm not far off being a total newbie, my sum total metalworking experience is made up of making a very crude version of a ball turner, and then making this,



for my better half's mobility scooter to give better illumination. ( i figured on some browney points for doing my first project for my better half )That took me about 2-3 months and was mostly lathe-work and just finished it this week.

As to the clamping methods and any other techniques I use, I must confess to stealing borrowing them from others such as yourself who do so many wonderful writeups. I have been avidly studying this and the other forum and every other machining website for at least 12 months before I got a workshop set up. I like to read how others do things and try to emulate them.

My only other experience is with woodturning, I've been turning wood for about 7-8 years, but as I've found out, wood is a completely different kettle of fish.


Tim

[Darren]

In that case I feel you are going to become a very competent metal basher cos that's some good work you are turning out there 

[Divided he ad]

Nice start Tim 
So how do you turn a kettle of fish with out losing the water and the fish?   


Wood turning... Now there's a missing section in the postings..... When you're ready      


There is a little secwet about some of those engines.... Look at many of the plans and you will see that some of them share parts, frames, cylinders etc.... Good thing to bear in mind if you think about making some as gifts etc?

My #16  uses the same frame and cylinder ... Just the holes differ 


Those lights look interesting.... A couple of pictures in the relevant section of the forum "Gallery" perhaps?

As to the clamping methods and any other techniques I use, I must confess to stealing borrowing them from others such as yourself who do so many wonderful writeups. I have been avidly studying this and the other forum and every other machining website for at least 12 months before I got a workshop set up. I like to read how others do things and try to emulate them.

That's why most of us are here Tim    I've picked up loads of info over the last year.... Forums that are nice to be a part of really help you get things made 




Looking forward to the running vid'     (I like the Bond ref' too  )






Ralph.

[spuddevans]

So how do you turn a kettle of fish with out losing the water and the fish?

The problem is not the turning, once the kettle's turning centrifugal force holds the fish in.  The challenge comes in trying to get it started. You have to turn your lathe 90degrees to be in the upright postion, start it and then carefully return it to the normal position to turn. 


I'll have to take a few more pics of the lights, I didn't take any "in progress" pics, but I'll take some "after progress" pics and make a post in the right section.



Tim

[Bernd]

Tim,

Have to agree with Bogs. I won't have believed you were a total newbie at metalworking. 

I like the idea of using the 1-2-3 blocks as an angle plate.

Once you get her runin' at 115pis for a few hours of run in you'll be able to get down to 5-10psi. 

Nice work with what you got. Keep it up and you'll have your first running engine in no time. 

Bernd

[spuddevans]

Have to agree with Bogs. I won't have believed you were a total newbie at metalworking. 

Well I'll take that as a compliment, I guess.    I really do think of myself as a newbie.

This was the 1st time of machining brass, I kinda felt the need to hold my breath while turning it as it seems to produce a lot of fine dust/shavings, it looks like there's been a shower of gold on my little lathe 

I like the idea of using the 1-2-3 blocks as an angle plate.

I was limited by my lack of equipment for holding the frame reliably in any other way, so the 1-2-3 block seemed to be the only choice for me, once I got one squared up to the table and clamped I was able to use the other one to make sure the workpiece was also square by using it standing up and just holding it with my fingers to the clamped block and at the same time ( and amazingly with the same fingers ) holding the workpiece to the upright 1-2-3 block. It probably was not square to the 0.001mm, but I figured it was square enough for me.



Tim

[bogstandard]

Tim,

once I got one squared up to the table

When you have a bit of spare time, turn yourself up a couple of short rods that are a very good fit in the t-slots in the mill. Then all you have to do is put the bars sticking up in the slots, push whatever you want to square up against them, and clamp up, job done in seconds. They are the first bits of machine tooling you need to make when you get your mill.

I actually made mine square, so that they can sit very low in the slots for thin work, or stood up for taller jobs, I suppose you could just angle the round ones in the slot.




John

[spuddevans]

When you have a bit of spare time, turn yourself up a couple of short rods that are a very good fit in the t-slots in the mill. Then all you have to do is put the bars sticking up in the slots, push whatever you want to square up against them, and clamp up, job done in seconds. They are the first bits of machine tooling you need to make when you get your mill.

Ahh!!! ( lightbulb goes on above head ) That is a great idea. What a timesaver, saves doing like me and trying to juggle an engineers square, 3-2-1 block, clamps and little adjustable-height-stand-off-thingys and a spanner to tighten the whole contraption up. 

Thanks for that tip Bogs, I'll turn a couple up asap.


Tim

[Brass_Machine]

Tim,

Very nice. I will second everyone's statement... you sure you are a newbie??

The 1st thing I ever milled was a part to fix SWMBO's sewing machine. Good idea on doing something for her first. That right there should justify the cost of your 'toys'.

Eric

[spuddevans]

Very nice. I will second everyone's statement... you sure you are a newbie??

Well, the last time I checked I was a newbie  and my progress report may just bare this out.

This afternoon I spent a total of 3 hours to mark out and bore just 1 hole 

The marking out went easy enough, and I even managed to center punch on the "x"    I even got it mounted in the 4 jaw and centered up within a gnats whisker.



The center drilling went well, and even the drilling with progressively larger drills until the bore was 3/8" ( this time I had an imperial drill set, so no metric convertion needed )

It was at this point I realised that the 9.5mm and 10mm reamers I thought I had as a part of a set were not there, the set only went up to 8mm and all are hand reamers, not machine reamers, and so even if the set went up to the needed size they would be useless as the bore is blind and only just over 1" deep.

So this is where the newbie-ness gets a little more obvious, instead of thinking that I could get a correctly sized and type (machine) reamer in a few days time, this numpty decided to spend 2.5 hrs trying to make one.

Sense has finally prevailed after making the bore look rather rougher than when I had just drilled it, and so I called it a day before I totally wrecked the cylinder blank.

So a total of 3hrs to bore one hole, and even that's gonna need reaming out. 

This is what it looks like,



So, that's as far as I've got.


Tim

[Bernd]

Tim,

Well you tried something and it didn't work. That's fine at least you tried.

Here's what I would have done and actually had to do on one of the two I had built. I bored it out with a boring tool. It didn't quite come to size so I made the piston to fit. The bore doesn't have to be the exact size to work, you make the piston to fit the bore. If you feel you messed it up you could try and put it back in the chuck, true it up and bore it out with a boring bar tool.

Bernd

[spuddevans]

The bore doesn't have to be the exact size to work, you make the piston to fit the bore. If you feel you messed it up you could try and put it back in the chuck, true it up and bore it out with a boring bar tool.

Thanks Bernd,
I would've bored it with a boring bar but both my boring bar tools are too big  I need to get a smaller boring bar.

Fortunately there seems to be enough meat left on the blank to bore it out a bit more.

Oh well, one to chalk up to experience 


Tim

[bogstandard]

In all honesty Tim, I have all the reamers, but I still prefer to bore cylinders. They turn out much more parallel and round. Plus unless you have a floating tailstock holder, you are almost guaranteed to get an oversized hole with a machine reamer.

Never say you haven't got a boring bar the right size if you have an old drill that is smaller than the hole you are boring. You can just grind a flat face across the end, mount it into your toolpost with one of the ground flutes sitting level, then put a couple of degrees on your toolpost so that the ground tip hits the wall of the bore before the rest of the drill, and away you go.

This is a get you out of the s**t method, not a permanent replacement for a boring bar.

You can try grinding a bit of front rake if you feel up to it. It is really a bit of trial and error, but once you get the hang of it, you will never get stuck again

With regards to making mistakes, it is all in the learning process, they get fewer the more you learn, that is of course, unless you can walk on water.

Bogs

[spuddevans]

Thanks Bogs, that will help me out a big load. I've just looked at the prices of machine reamers 

I was thinking that using a reamer would give me a good parallel bore, but if boring the "bore"  results in a better "bore" I'll stick with that method.

Do you know where I could get a reasonably priced boring bar from that would be usable in say 8mm and upward holes? I have one that works from 12mm and up, but I now can see the need to get something smaller.


On the subject of making mistakes, I truely believe that the man who hasn't made any mistakes hasn't made anything.


Thanks again for your help with this, truely 

Tim

[sbwhart]

Tim

We all have bad days if you've read my loco build thread you'll see I scraped off a cylinder casting that cost £80 when boring it, a new one cost me another £50:-  ouch   

Setting it up again and taking a light cut with a boring tool as John suggested will sort you out, it,s easyer to do the bore first and not worry too much about the size then make the cylinder to fit, most people do it that way. One little tip when boring:- boring tools have a tendancy to spring it will cut as you wind it back if you don't take the cut off, zero the dial and run the finishing cut through a couple of times until all the spring gone out of the bar.

Don't throw away any bits of broken tool steel:- centre drills, drill, mills cutters etc: as you can always grind them up for other uses.

Have fun

Stew

PS Just read your question on boring bars, if you have any HSS square steel you can grind this up into a boring bar, if it would help I'll post some pics tomorrow night of some bars I've made.

Cheers

Stew

[spuddevans]

PS Just read your question on boring bars, if you have any HSS square steel you can grind this up into a boring bar, if it would help I'll post some pics tomorrow night of some bars I've made.

Thanks Stew, I'd love to see those pics. I do have a couple of spare HSS square blanks, but I think they're too large for the bore. ( I think the smallest HSS is 3/8 square, and I dont fancy grinding down the whole length to make it fit. ) I'll half to get some 1/4" Hss blanks.


Tim

[bogstandard]

Tim,

As Stew says, You can grind up boring bars out of tool steel, it all depends how good you are on the offhand grinder.

For commercial ones, go down the page on here a bit and you will find some.

http://www.arceurotrade.co.uk/Catalogue/Cutting-Tools/Lathe-Tools

Bear in mind, the smaller they go, the shorter they are, due to the forces acting on them, small ones are very easy to break. The smallest I have made using the drill method was 1mm, and it did the job, just.

You can also use the carbide tipped ones they sell in sets for mounting in boring heads. In fact if you look at the heads on those, they should be roughly the same shape as I am showing here.

Proper boring bars are in fact very easy to make yourself. But you do need to be fairly confident on the offhand grinder.

As shown on the C-o-C, turn up the shape required from silver steel. Try to keep the turned down bit as large as possible, this will reduce the  danger of breakage and keep vibrations down.

Then grind the end bit to the shapes shown

When you are happy with the cutting head shape, heat up the cutting head only to cherry red, and hold it at that for a minute or so, then plunge it into water, but don't swizzle it about, that should keep stresses to a minimum and prevent fracture. I like to leave the centre turned down section unhardened and use its natural toughness to prevent breakage. Also, because I have only hardened the head, I don't temper it.
Touch up with a stone the front and side cutting faces.

Mount the cutting tip exactly on centreline, and remember, you should NOT be removing large wedges of metal with a small boring tool, drill out the hole to about 1/2mm under, and use the bar to bring the hole up to the right size.
 
Once you get used to it, you can easily knock one up in 15 to 20 mins.


Bogs

[NickG]

Nice instructions on the boring bar John. I've got 1 just like that , I assume my grandfather must have made it at some point as the back end of it is relatively soft, it came with a load of bits and bobs I inherited from him. I could do with a few in various sizes.

Nick

[spuddevans]

You can also use the carbide tipped ones they sell in sets for mounting in boring heads. In fact if you look at the heads on those, they should be roughly the same shape as I am showing here.

 

You wouldn't believe how much of a numpty I feel. When I read your post Bogs it hit me like a ton of bricks, "I have a boring bar set for my mill"  ( looks around for the hole in the ground to appear ) But I will file your C-o-C for future reference thankyou very much 

Anyway, when I finally got over my numptyness this is what I got done today. I mounted the cylinder blank into the 4jaw, centered it and then took a couple of light skimming cuts and then about 4 repeated cuts to eliminate any springing of the boring bar.


I then remounted the cylinder the other way and bored out the pivot pin socket being careful not to break through into the piston bore.


Onto making the pivot pin. I didn't have any small diameter brass bar and I didnt fancy wasting some 3/4" square bar. I thought I'd try and be clever and use a little piece of 19mm x 3.5mm flat stock and turn it down. So I cut some off and chucked it in the 4 jaw.


Then to turn down the other end I wanted to chuck it in a ER32 collet to not leave markings on the pin, but I dont yet have a ER32 chuck for my lathe, but I do have a MT3 ER32 chuck for the mill, and the headstock on the lathe is also MT3. Not having a long enough drawbar I brought up the tailstock to ensure that I wasn't chased around the workshop.


Once the pivot pin was turned down to the right size to be tapped M3, I then cut the M3 thread. You probably noticed that the tailstock is removed for this, I ran the lathe at the lowest speed ( I thread at the lowest speed so I dont run into the chuck ) and as I found out when trying to remove the ER32 chuck it was well stuck in there.


Once that was done, I removed the pin and then loctited it into the cylinder. (it was a pretty good press fit)



And that's as far as I got today. Thanks to Bog's for reminding me of what I actually had sitting in the corner of the workshop.


Tim