Cat 340D Excavator build

[crueby]

Hi Frizzen, there is a chain drive inside the tracks, with a 1/4" pitch bike style chain. Sprocket on the shaft with the motor, chain up to another sprocket on the track drive wheel. The drive wheels were two part castings, so I trimmed one side to make room for the sprocket in the center of the hub. That way the chain is not visible without looking inside. Having the chain inside made for some trade-off with the design of the track road wheels down the length, had to make them a little larger so things would clear.