Shown here is the method I employed to create a dampening sprocket of the mk IV drive.  This will require some lathe work....

Here's the fixture I machined to realign the hub and the rim of the sprocket when i pour the rubber into the two parts.

The raised pin in the middle holds the hub and the outer perimeter of the fixture places the rim in precise alignment, retaining accuracy of the sprocket.

Shown here is the sprocket pieces after machining them apart.
Sprocket parts cleaned up with MEK and then Denatured Alcohol.  The Denatured alcohol is the solvent you will want to use to clean up the rubber before it sets.
Nope, it's not Pepto Bismol®, it's Castaldol's Liqui-Cast jewelry casting rubber.  This is NOT silicone rubber.  It will set up at room temperature, 5 hours to set and 16 hours to cured.
The finished molding, ready to clean up and install.
The installed gear on the (now) mk V drive.
 

 

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