Steam Engine Build/Piston Connector Rod

Steam Engine Build Instructions

=Description=

The connector rod connects the piston stem to the crank on the crankshaft. One end is fixed to the piston stem and travels in a reciprocal, linear motion. The other end is attached to a crank on the crankshaft and travels in a circular motion. The crankshaft end contains a bearing case and ball bearings to reduce wear on the crankshaft.

The connector rod is built up from three elements:


 * Coupler
 * Bearing Case
 * Rod

=CAD=

Coupler

Rod

Bearing Case

Connector Rod Assembly

=Drawing=





=Instructions=

Coupler

Using a piece of high quality steel:


 * 1) Cut a 1.5" length from 1.0" square bar stock
 * 2) Drill a 0.5" dia hole in one end to a depth of 0.75"
 * 3) From the top face, drill a 0.25" hole at 0.5" from the left end.
 * 4) Cut a slot 0.25" wide to meet the hole just drilled.
 * 5) Bevel the piece at a 45 degree angle as shown
 * 6) Drill a 0.25" hole 0.25" from the end into the side face

Bearing Case

The bearing case can either be milled from high quality steel, or the circular portion turned on a lathe and bolt tabs welded on.


 * 1) Drill bolt holes 0.25" dia.
 * 2) Inside bore is 1.2" dia to hold a bearing unit with a 1.0" bore (shaft size)
 * 3) A cylindrical channel is cut inside 0.5" wide and 0.647" deep

Assembly


 * 1) Cut a length of 0.5" rod 5.0" long
 * 2) Insert the rod into the coupler and weld it
 * 3) Insert the rod into the bearing case and weld it.