Model Engine Maker

Engines => From Plans => Topic started by: cwelkie on April 28, 2022, 11:23:16 PM

Title: Elmer's #42 Oscillating Cylinder Engine
Post by: cwelkie on April 28, 2022, 11:23:16 PM
For some reason this little design has held a fascination for me ever since I first saw the drawings.  After completion of the last "larger" project I thought it time to finally get this one done.  It was a good way to use at least some of the tiny bits in the Brass Box.

https://youtube.com/shorts/1WSir95bfBQ?feature=share (https://youtube.com/shorts/1WSir95bfBQ?feature=share)
Title: Re: Elmer's #42 Oscillating Cylinder Engine
Post by: EricB on April 29, 2022, 02:07:03 AM
Nice little engines. I built one last year: https://www.modelenginemaker.com/index.php/topic,10234.0.html

How did you create the "U" shaped frame?

Eric
Title: Re: Elmer's #42 Oscillating Cylinder Engine
Post by: Kim on April 29, 2022, 05:00:03 AM
Great little runner there, cwelkie!  :ThumbsUp: :popcorn:

Kim
Title: Re: Elmer's #42 Oscillating Cylinder Engine
Post by: cwelkie on April 29, 2022, 02:13:31 PM
Thanks guys. I find Elmer's engines fun to do while considering "What's next" questions.

 Eric - I started with a 1" wide, over length piece of 1/4" aluminium flat bar.  Simply used a length of 1" diameter rod as a form/mandrel, my vise and dead blow hammer to bend the arc.  As the sides got closer together, I clamped the rod into the "pocket" being formed to ensure the circular shape was maintained. As the sides approached the intended distance apart, I used a couple of blocks machined to the inside dimension to gauge and control the bend.

Once the plan view shape looked good, I put the part in the milling machine vise with the above blocks  used as spacers and the part "level".  Then the top and bottom surfaces could be surfaced back to be flat and to the target height all around.  (I didn't have any 5/8" material suitable for the base so used 1/2" for the base and made the U-shaped piece 7/8" tall.)

The bearing block locations were machined and drilled after the U-shaped piece and outboard bearing support were bolted to the base.  The assembly could be clamped in the vise and this ensured a consistent height and alignment at all 4 bearings.

Charlie
Title: Re: Elmer's #42 Oscillating Cylinder Engine
Post by: Dreeves on April 29, 2022, 03:47:21 PM
Great looking engine. I finished mine about a year ago. I made my base as a solid using my cnc. I was not keen on bending the u shape.

Dave
Title: Re: Elmer's #42 Oscillating Cylinder Engine
Post by: propforward on April 29, 2022, 03:57:08 PM
That's a very fun engine.  :ThumbsUp: :ThumbsUp: :ThumbsUp: :ThumbsUp: