Elmer's Fancy II

[EricB]

I'm working my way through Elmer's turned body wobbler engines and this is the last and the largest (I think). The body is 4 1/2" long and 1" in diameter.

Yesterday I cut the stock and commenced to rough out the shape of the body, then realized I'd cut the piece too short. Measure twice right? Rather than start again I moved the stock out of the chuck enough to give me room to work. So far, so good, but it could be interesting later.

Today was day two of turning the body. Most of the time was spent trying to make the round ball section look like a sphere. Large cuts with the compound and finishing with files. The best I could do was the elongated ball shown. After I quit for the day I figured out what I was doing wrong. I kept thinking I needed to see a full 1" wide curve of the ball, but part of that is taken up by the 1/2" circle where the sphere meets the cylinder of the body on each side. More forgotten math.

Eric

[EricB]

Sort of quit for the day anyway. Did the math, narrowed the visible portion of the sphere and reshaped the rest. Still a little bit wide but looks much better. 1" rod for reference.

Eric

[EricB]

Still trying to make scrap.

Yesterday I finished the shape of the engine body, even thought I got most of the dimensions right. So I moved it over to the mill for the next phase.

Making the flats went well. I like using this kind of setup because it eliminates the residual error in the table along the "Y" axis, and lets me reposition the part.

Next I had to drill some holes. I laid them out according to the dimensions and drilled/bored/reamed them. Hit all the targets too. Then I looked at their locations relative to the features they were going though. Oops! Two out of three were off center. When I shaped the ball I marked the center off of what was not a finished surface. When I finished the surface it changed the dimension but I didn't think of it at the time. For the hole at the left end I just made the feature too wide.

To fix them I found the centers of the features and enlarged the holes to bring them on center. The crank bearing (left) and the mounting post (ball) will need to be oversize now but I can hide the mistakes. I'll need to adjust the length of the connecting rod too.

Eric

[EricB]

Only a couple of little parts today.

I made the bearing bushing for the crankshaft and found a piece of unknown origin steel to use as the shaft itself.

I also made the center post for the base. It's necked down to 3/8" at the bottom so that I can make the other base part according to the plan. It's tapped 10-32 from the bottom. Once I have the base complete the center post will be held into the body with some adhesive. I'll make a similar knob to fill the hole used by the dead center.

With most of the engine made from aluminum, I had to spend a good amount of time removing a bird's nest from the hose of my shop vac.

Eric

[EricB]

Made the base using form tools, files and gravers. I copied the plan design for the most part. It's about 1/8" taller where the center part meets the foot. Then I made the foot so that the center part will nest into it. That way I didn't have to worry about trying to make two flat surfaces sit flush and everything stays concentric.

The plan has two mounting holes at the edge of the foot. I omitted those. I'll use the single screw under the base for that.

Eric

[crueby]

Wow - looking fantastic!!   

[Krypto]

It's tough to get all the fancy curves look good in metal.  Great job!

[RReid]

That looks really perty, Eric. Nice work!

[EricB]

Thanks for the comments. I spent a couple of hours making and blending the curves on the center part of the base. This is my largest freehand turning to date. If the lighting is right it does look good.

Today I made the jig for the steam passages and drilled those. After that the body was parted from the stock, leaving about a 5/16" slug which was just barely enough.

I still want to make some decorative features on each end of the body. For the crank end it's just make and fit, for the cylinder end I'll need to turn it down first.

I don't have the tools to make the cylinder as the plan shows. It shows a blind 1/2" bore that's 2" deep. I'm not sure I can do that with my Sherline lathe even if I had the drill and reamer, and the boring head is out of the question. My current plan is the drill and ream through the rough stock on my drill press and solder a cap on the end of the cylinder, then finish the outside to size and shape.

Eric

[cnr6400]

  Great work! 

[EricB]

Fresh supplies arrived today so I got the flywheel turned. I just happened to have a mandrel from a previous build that worked without alterations.

I don't have the right size brass or the tools to make the cylinder yet. Waiting on the mail. Everything I buy online seems to get lost in St Louis.

Eric

[Admiral_dk]

Beautiful work and parts     

Per         

[EricB]

Thanks for the comment. I need to work on making my flywheels more interesting.

Today I made the crankshaft. Most of the time was on the disk of course. The radius beween the throw and the counterweight is an endmill size I don't own, so I had to get creative to make it come out close to the plan. It amazes me how much work can go into a part so small. At least it's visible when the engine gets finished.

I can make the connecting rod and finish the decorative parts of the body, but everything else will have to wait for the cylinder.

Eric

[EricB]

I found I had a piece of brass I could use for the cylinder. The piece was 1" square and 3/4" is called for so I had to cut it down.

The first setup looks kind of dicey but it was quite rigid and was so much easier than the hacksaw method. I did need to reposition the stock in the vise for last cut. The first cuts left a wedge shapped section at the bottom where the saw could not reach. All that was left was a tiny bit in the center which broke with a slight twist.

Trimming the first side was a little more difficult. The saw left a strip down the center that I could not break and I had to use a hand saw to get it free. The second side cut off without intervention.

The good part is I didn't convert all the brass to chips like I have with the aluminum parts, and the off cuts are still useable.

Now I'll see if I can bore the cylinder...

Eric

[EricB]

Not wanting to wait, I decided to bore the cylinder with whatever tools I have on hand. The goal was 1/2" dia and 2" depth.

I started with a 3/8" drill. Not the best choice for a MT0 taper tailstock but I made certain it was braced so that it could not spin. That worked but the lathe motor couldn't handle the load.

Take two, I drilled to depth with a 1/4" drill. No problem. Then went to my longest Sherline boring tool which could only reach to 1.25".

From there I went to my cheap import carbide boring bars. No joy, just chatter. Even chipped one of them. Trash.

Back to the drills, I had 3/4" more to bore so I used larger drills in steps up to the 3/8" I started with.

The last tool on my list was a 1/4" endmill. I had to make a split sleave for it to fit my boring bar holder. After that it still took a bit of trial but I finished the bore the 2.008" depth and 0.496" dia. I can live with that.

Eric

[paul gough]

A method I find very convenient with my Sherline is to turn the barrel of the cylinder then transfer the chuck to the mill by using the chuck adapter, mine is in the rotary table, then spot drill (120 degree), drill and ream the bore. I get satisfactory results in brass without the need for lapping. This ability of swapping chucks from lathe to mill or vice versa is a very useful feature. With the 4 jaw on the rotary table I still have a bit over 150 mm (160 with 3jaw), of distance between the top of the chuck jaw and the face of the ER 16 collet nut. Plenty for my 9.5/10 mm cylinder bores. Probably enough room, just, for 12/13 mm if you shortened the shank on the drill, which I do, as the 10 mm ER collet can cope with a 12mm drill in brass without any issues. The Extra height with the 15 inch column is a boon, suggested by the Sherline master Chris Rueby. I find the ER 16 spindle lathe and mill excelllent and accurate. Regards, Paul Gough.

[EricB]

Paul, Thanks for the insights. I considered drilling and reaming on the mill or drill press, and though I could get the bore to size, I could not figure out how to get it to depth and achieve the geometry needed at the blind end. If I drilled to depth at the point of the drill I'm left with a 120 degree cone shape and no clearance for the end of the reamer or the top of the piston. I would still need to somehow shape the blind end of the bore. If I drilled to depth at the diameter of the flutes the drill point breaks through the end of the cylinder.

The diagram makes it look simple enough, and I have made other Elmer engines using similar paterns, also blind only smaller. For those I drilled and bored to depth and then reamed to size. The clearance drill for the boring bar was easily handled by my lathe, and I could flatten the blind end and make the relief "groove" for the reamer with the tip of the boring bar.

For this one the diameter and depth of the bore was the issue for me. I have a long insert boring bar, but the clearance hole is about the size of the final bore I needed. I think in the future I'l knock the carbides off the tips on my cheap inport bars and grind the remaining material to suit the task.

Eric

[paul gough]

Hi Eric, Sometimes my old brain gets lost, I forgot you are doing blind bores and my method applies to through bores. Hope I did not waste your time reading my irrelevancies. I am following your build for insights as I want to make the slide valve oscillator from Elmer, maybe try to incorporate a Penn link and reverse. Regards, Paul Gough.

[EricB]

Paul, No worries! I appreciate the input. My first Elmer engine was a slide valve oscillator, #42 in his book. I'm thinking of making another or a derivative of it. I've looked at several engines of that type and I can't figure out how you would reverse one.

Today I made another expanding mandrel so I could shape the outside of the cylinder after I finished with the other work on it. The plan has the outer curve centered on the 3/4" stock. I left the stock a little oversize so I could center the curve on the bore. The final dimensions I'm aiming for are 3/4" across the port face as per the plan, but 13/16" to the top of the curve. I may bevel the top edge too. We'll see.

Eric

[paul gough]

I too tried to come up with some sort of reverse, but failed to accomplish anything workable. Then stumbled on a Penn stationary engine with a curved link with further searching found Penn made a reversing marine engine, a working example is in a German paddle wheeler named the “Diesbar”. A low pressure, low rev, twin cylinder with slip eccentric reversal. Quite a mind stretcher to comprehend all the gear movement, at least for my rather feeble faculties, but as luck would have it a German model maker has built a replica of the engine. He authored a booklet (presumably still available as I only got mine some months ago). MichaelS And Crueby gave details to me. It is in German, but I fumbled my way through doing a rough translation. The drawings make most things understandable. It will be some time before I can get onto this project though. The details of the booklet are: Author is Josef Reineck; DAMPF 44, Die Diesbar Schiffsdampfmaschine, Neckar-Verlag, 2016. From memory I got a copy from a British supplier. Will try to find who and post it later. Regards, Paul Gough.

[paul gough]

Can’t find the seller I got it from for sure. But I used AbeBooks and they have it listed with Revaluation Books UK. US $27. Quite possibly my source, but there are many other offerings if you search the title and author. Regards, Paul Gough.

[crueby]

I think I  got my copy of the Diesbar book from AbeBooks too. I scanned the pages and ran it through OCR then a German to English translator, to get the text. I've  taken the plans in the book and made a CAD version, on my list to build someday too. The valve motion is quite interesting with a slip eccentric to do the reversing. The engineer has to disconnect the link and manually move the control rods for the start of the first revolution in the new  direction. There are a number of videos online showing it.

[EricB]

The engineer has to disconnect the link and manually move the control rods for the start of the first revolution in the new  direction. There are a number of videos online showing it.

So I guess there's no changing directions on the fly, huh? Interesting.

I spent too much of my wife's time talking about steam engines this morning so she banished me to my workshop. Oh darn.

Eric

[EricB]

I found a listing for the book on Amazon.

And this:
https://www.asme.org/wwwasmeorg/media/resourcefiles/aboutasme/who%20we%20are/engineering%20history/landmarks/245-john-penn-sons-oscillating-steam-engine-18.pdf

Eric

[crueby]

The engineer has to disconnect the link and manually move the control rods for the start of the first revolution in the new  direction. There are a number of videos online showing it.

So I guess there's no changing directions on the fly, huh? Interesting.

I spent too much of my wife's time talking about steam engines this morning so she banished me to my workshop. Oh darn.

Eric

In the videos online, it only takes the a couple seconds to change direction, at least for their experienced engineers!

[EricB]

In the videos online, it only takes the a couple seconds to change direction, at least for their experienced engineers!

I haven't found the videos yet. The engine has an interesting history!

Eric

[crueby]

In the videos online, it only takes the a couple seconds to change direction, at least for their experienced engineers!

I haven't found the videos yet. The engine has an interesting history!

Eric

Here is one. Shows the engine running in a couple places


<a href="https://www.youtube.com/watch?v=t4DiXpf2Zaw" target="_blank">http://www.youtube.com/watch?v=t4DiXpf2Zaw</a>


and another
<a href="https://www.youtube.com/watch?v=bDp8T91iIKE" target="_blank">http://www.youtube.com/watch?v=bDp8T91iIKE</a>
one more
<a href="https://www.youtube.com/watch?v=9G2WD09HtCc" target="_blank">http://www.youtube.com/watch?v=9G2WD09HtCc</a>
Oh, and if you turn on subtitles, then go into settings and pick auto-translate and English, it will give you the subtitles in english (tested on the third video, didn't try it on the others)

[EricB]

Back to my engine, I finished the major work on the cylinder. The final cuts were at 2.5 degrees per pass, that's 72 plus a few extra. I didn't keep track of the number of passes before that but it was lots of handwheel turning. I kind of like the finsh though.

I somehow did not get the cylinder pivot aligned with the body pivot. I laid them out and spot drilled both on the mill so I probably didn't get the backlash in the table leadscrew going in the same direction both times. I'll leave it.

Eric

[crueby]

Looking great! The rounding over came out fantastic.

[EricB]

Thanks Chris.

Once I got the corners knocked off the rest went fairly smooth. Tedious, but smooth.

Eric

[EricB]

Only three small parts today, the cylinder pivot pin, piston, and connecting rod.

Earlier the cylinder was drilled and tapped 10-32 to accept the pivot pin. Doing so raised a burr on the inside which I discovered when I made the piston. Since I didn't ream the bore to a standard size (no reamer on hand) I had to knock down the burr with a small half round file. It's not a critical area as it's completely covered by the piston except at bottom dead center.

The piston is to size (length anyway) to the plan.

The connecting rod is shortened to compensate for the change in distance between the cylinder pivot and the new crankshaft position.

This completes all the major components. I still need to drill the steam passage into the cylinder, make the spring and nut for the cylinder, get or make a set screw for the flywheel, and finish the decorative features of the main body. The permanent installation of the crank bearing and drilling the oil hole will be last.

Eric

[paul gough]

The name ‘fancy’ is not sufficient for this work. Classy at least! but my preference would be elegance. Either way, a simple engine made into a delightful object. Complex engines are a marvel, but sometime ‘less is more’ and this is a classic demonstration of it in my opinion. Hope everything will run smoothly and slowly. Regards, Paul Gough.

[EricB]

The name ‘fancy’ is not sufficient for this work. Classy at least! but my preference would be elegance. Either way, a simple engine made into a delightful object. Complex engines are a marvel, but sometime ‘less is more’ and this is a classic demonstration of it in my opinion. Hope everything will run smoothly and slowly. Regards, Paul Gough.

I do like the more artistic engines!

[EricB]

I'm almost done with this one.

Today I completed the cylinder, wound a spring from brass wire, made the cylinder pivot nut (I had borrowed a nut from my hold down set and I liked the look so I copied it.), and made a set screw for the flywheel.

Well that's enough to make an engine so I gave it a shot of air. It ran for a few seconds before the big end of the connecting rod seized to the crank pin. I fixed that and added a few drops of oil in the appropriate places and it ran fine the second time.

After much thought I decided against any decoration on the cylinder end to the body and turned it flat. Then rounded and drilled out the center hole on the crank end to accept a small plug, to come later.

All that is left is to try and improve the finishes (It seems like everytime I touch it I leave a mark), make the bearing and center column permanent, and drill the oil hole for the crankshaft. For now I'll call this one done!

I think that compared to most of Elmer's other wobblers this is a large engine. I'm glad I decided to give it a try. I've included a group shot of this year's builds for scale.

I still have a PMR #3 waiting but it's almost warm enough for gardening!

Eric

[EricB]

<a href="https://www.youtube.com/watch?v=8ukc4oV9r28" target="_blank">http://www.youtube.com/watch?v=8ukc4oV9r28</a>

[Kim]

Beautiful!  It just runs to beat the band, doesn't it!     

Kim

[Krypto]

Great build and engine! Thanks for taking us along for the ride.

[Roger B]

Very nice 

[EricB]

Thanks for the comments. I really enjoyed the process of making these.

I learned a few more lessons along the way, like make sure the stock is long enough to make the part. I learned that Loctite 271 won't hold aluminum to aluminum because aluminum is non-reactive, but it works fine with brass to aluminum. I learned I need better tooling if I ever need to bore a deep blind hole again. I also learned I need to check machine alignments before I start a project.

Eric

[JCvdW]

Beautiful!