This project is from Jerry Howells plans for a
tiny atmospheric engine (flame sucker). The cylinder OD is 1.5 in. Bore is
.600 , Stroke is .874. I have in a few instances strayed from the plans
because there were some things, machining wise, I wanted to try to improve my
skills. I wanted a spoked flywheel so I made a wooden horizontal rotary table
and indexer to go on my mini mill to accomplish it. It was also useful for
making nonstandard size holes such as the hole in the frame for the cylinder.
At the time I was such a novice that I barely knew what a rotary table was. I
plan to get a real one- but this one worked pretty well. I also decided I
didn't want to fabricate the little fan from sheet metal as per the plans. It
was made in two pieces from solid bar stock by first turning the hub, pulley
and blades as a single disc and then (very carefully) milling the blade slots
on the rotary table with 1/8 in. end mill. The blades were twisted to a set
angle and the whole thing placed inside a ring turned from bar stock and
All the parts and pieces are now ready for first
assembly and running. Then to take it all down and polish everything up and
Jerrys plans were cad drawn and I had never seen a
cad plan. I had to look hard to find some of the dimensions. If you look hard
enough the answers are all there.
Copyright 2004, Florida Association of Model Engineers
and engine builder as noted above,
All rights reserved.