Flywheel for Elmer's #50 Educational engine

[Mike Bondarczuk]

Hello to all readers,

I have been following and commenting on AOG's build log of Elmer's #50 Educational engine whilst also building an identical engine but to Elmer's original scale rather than the 2X size drawn by Julius and built by AOG.

I followed the imperial dimensions to the "thou" with the exception of the fasteners where I changed from the US sizing into metric sizing by replacing #2-56 with M2.2, #3-48 with M2.5 and #4-40 with M3.0, which seemed to work OK.

The subject of this write-up is related to the production of the flywheel to Elmer's design and I am grateful to Marv for his input in providing me the necessary co-ordinates to mark the starting holes and angles on the rotary table.

The only departure from the design is that I increased the thickness of the flywheel from the original 1/4" to 1/2" and proportionally increased the dishing from the original 1/16" each side to 1/8" each side in order to maintain symmetry.

The steps taken are as follows:

1: centred wheel blank in a 4 jaw chuck on my lathe and transferred the complete assembly to my rotary table.

2: checked centre with edge finder in X and Y axis and validated concentricity of the circumference.

3: spotted outer and inner holes at the radial settings required and drilled the holes 1/64" undersize and then reamed to the 1/4" and 3/8" diameters specified.

4: using a 6mm 3 flute milling cutter cut through in depth stages of about 25 thou for the radial cuts in the outer ring and the  using a 1/4" 2 flute milling cutter gave finishing passes to size.

5: found that I needed 3.5 degrees offset for parallelism  and since I was using the 6mm cutter offset the Y axis by 0.349" to be able to cut out for the spokes in a clockwise direction and the reverse settings for the other side of the spokes in an anticlockwise direction.

Everything seemed to work out very well and I am attaching a few pictures of the process at the various stages and trust that there are no major errors in my machining set up.

My thanks for AOG for his build log as a guide as well as Marv for his contribution to the rotary table settings.

Mike

[Mike Bondarczuk]

A second set of pictures related to the flywheel build

Mike

[Mike Bondarczuk]

And finally a third set of pictures recording the process.

The engine is now running but in a machined state so the process of stripping down, final smoothing, painting and polishing is about to start, and when completed I will post a summary set of pictures as well as a running video.

This is not Elmer's most elegant design and for the colour scheme I am going with cream of the supports, black for the cylinders and other steel parts and will finish the flywheel off in a nice bright red colour but with polished spokes and rim.

Mike

[Jo]

  Well done Mike,

Looking forward to seeing the Video of it running.

Jo

[Flyboy Jim]

Nice looking flywheel, Mike. Also, well documented. I'm looking forward to seeing the finished engine running.

Jim