Elmer's #24 Beam Engine

[EricB]

I started working on this engine a couple of weeks ago. Actually I was just wanting to try turning a taper on my Sherline lathe by rotating the headstock. Since the Elmer's engine has a tapered center column, I was using that plan as a guide. I figured if I didn't make scrap, I'd go ahead and finish the engine.

The plans don't give dimensions for the taper or decorative features of the column. Elmer advised to make it "as fancy as you wish." I was was just looking to get close to his drawings. I figured the top of the column should be about 5/16" and the bottom about 3/8" so that's what I aimed for.

Here are the results of the initial work. There were a number of steps and material removal before getting to the taper, but eventually I had grooves cut down to the top and bottom diameters between the rings. From there I rotated the headstock what I thought was a good amount (I did not bother doing any math) and started making light cuts toward the tailstock. After a few more changes to the headstock angle I decided to touch off on the small end, note the handwheel setting, and transfer that position to the large end. Then I made one heavy cut toward the headstock. What I didn't realize at the time was by moving the large end I also changed the handwheel setting at the small end. The top came out a bit smaller than I wanted but I'm still happy with the results.

[EricB]

For the next week I thought about remaking the part. My concern was that there might not be enough material where the mounting hole for the piston support is drilled (AA in the diagram). I decided that if I could make the hole to its full depth then I'd press on. Success!

Starting with square stock gives you a built in index block, so the rest of the column top went very quick. I still need to shape the tops of the bearings and some light filing between them.

[crueby]

Looks like it came out great! I've run into the same thing on my Sherline, when tramming it back to parallel again, sometimes I also forget that rotating the headstock changes things at both ends of the part. When going back to parallel again, don't just assume that the key under the headstock will get it straight, it will be at least close but may need a minor tweak again. Taking a light cut down a couple inch length of bar, then checking both ends with a micrometer, will show how parallel it is.
 

[EricB]

Thanks Chris!

I try not to rotate the headstock (or remove it) if I can avoid it, but I have no other choice for this part. I'm sure that had I gone back and rechecked I would have noted the problem before I made the cut. I just didn't consider it at the time. Another lesson learned.

[EricB]

Yesterday I made a blank for the flywheel. It started as a 3" x 3 1/2" x 1/4" piece of aluminum plate. Rather than resort to using a hacksaw, I decided to cut away everything that didn't look like a flywheel using a slitting saw on the mill. The first time I tried using a slitting saw with aluminum I used a .020" blade thinking the narrower blade would work best. It didn't. In fact, it went so poorly that I vowed never to do that again. That was several years ago, and since then I would cut off aluminum with an endmill (or hacksaw). Still not the best idea. I should get one of those portable band saws some day. This time I used the thickest blade I have, which is .050". The wider blade made all the cuts without any problems other than getting oily "glitter" everywhere.

So far so good.

I held the now octagon shaped blank in the reversed jaws of my 4-jaw scroll chuck to first face one side, and then drill and ream the center hole for the eccentric and crankshaft. Flipped the blank over and faced the other side. I left it about .040" oversize so I can correct any mistakes when I cross out the spokes for the wheel (another process I have yet to try). Then it was onto a center mandrel to finish the OD to size.

Funny, but when I went to buy the 4-jaw scroll chuck I was advised that I would probably never use it. That has not been the case.

[EricB]

Today I've reduced the thickness of the center web of the flywheel and also reduced the overall width to size. My setup was not very rigid for this, so the more material that was removed the more it chattered.

[EricB]

My first attempt at crossing out a flywheel on a rotary table. I didn't do the math for the spokes, just eyeballed the angles and table offsets. I bit of filing and it's done.

[crueby]

Good eye! Came out great.

[Grateful Ted]

Eric your parts turned out very good, i like ‘em.
A few years ago i finally bought a portable band saw, i find i use it a lot, although i still use the hacksaw on tiny parts.

[EricB]

Thanks for the comments!

Today I made the eccentric hub. Twice. Took all afternoon too. I was thinking about going for three but I managed to salvage this one. That's enough about that.

[EricB]

After some mental recovery time from the eccentric(s), I made the crank throw. I don't have any material the correct size for the pin so that will come later. No more steel for a bit.

Sometimes it's the little bits that cause me the most trouble.

[EricB]

Started on the base today. I do not have anything near the correct size flat stock, so I knocked the curves off of a length of round using my new Sherline insert fly cutter. I have to say I like it, but I'm convinced that the real purpose of a fly cutter is to throw chips into the future.

[crueby]

If it threw the chips into the past, you would have already cleaned them up...   




 

[Grateful Ted]

Of course, that explains it.
You purchased the Sherline milling/time machine fly cutting attachment.

[samc88]

Nice work on the flywheel, making good progress