To make the ratchet hubs, we again started with standard kart hub blanks.
Previously, I searched around and found a ratchet box wrench that I felt would handle our torque needs and was also reversable. We'll use the reversing feature to allow us to tow the cart around free from the transmission.
After putting the hub on a diet, I milled out a shape that matched the shape of the wrench head.
I grabbed a square swatch of aluminum for a lid -- drilled, tapped and cap screwed it on and then milled it round to match the hub.
I ground off the handle of the box wrench and installed three set screws to use for centering the wrench in the hub.
Once I fit, centered and locked in the wrench head with the set screws, I mixed up a small batch of epoxy and heated up the assembly (so the epoxy would flow). I let the epoxy fill up the space between the hub and the wrench head to make a nice, tight, torque resistant fit.
Here's a shot of the three in a progressive state of assembly.
