Counterweights

The drive wheels I’m using were cast without counterweights because they were designed for an early American type engine. I purchased aluminum blanks – 6 inch diameter discs; 0.080 inch thick for the back; and 0.125 inch thick for the front of the wheels.

I cut the counterweights to shape on my band saw. I measured the thickness of each wheel and made appropriate length aluminum spacers for each wheel. The spacers were tapped for #5-40 screws on both ends.

I mixed West System high density adhesive filler #404 with Total Boat epoxy. I screwed the spacers to the back plates and epoxied the back assembly in place and let them harden. I screwed and epoxied the front plates on and mounted the wheels in an upright position (see photos). Use waxed paper to protect tools and the workbench from the epoxy.

I used a large garden syringe filled with epoxy and high density filler to fill the cavity between the counterweight blanks.

The high density filler is composed of mostly powdered silica, so it is very difficult to sand off the excess epoxy. I was able to chisel and sand the backs of the wheels flat, so the wheels could be mounted in the lathe to machine off the excess epoxy from the front of the wheels and counterweights.

I used a rotary burr in a flexible shaft tool to clean the epoxy off the spokes.

I mixed epoxy and filler to the consistency of thick peanut butter, to fill holes and gaps in the epoxy.

Once the wheels are painted they will look like fully cast wheels.