Vex Shift Rod through 3/8 Hex Shaft?

[KohKohPuffs]

Originally Posted by AdamHeard

A dog gear doesn't make a great brake. It takes quite a bit of force to remove under torsional load compared to more traditional brakes.

The gearboxes I designed for 649's shooter arm this year had a brake component, which utilized an AM shifter block with the rod and a custom part which acted as the dog. It was basically a plate that shifts against a urethane brake pad. I didn't see the thing in action very much, but people tell me that it worked very well during the competitions and has never needed maintenance (not too sure about never failing).

I guess this would counter that a dog gear doesn't make a great brake. Compared to a traditional brake, not so sure. I don't really know what traditional brakes look like (... is it a bike brake?).

In general, hollowing out the center of an axle doesn't cause too many strength issues. IIRC 1/2" thunderhex is 92% as strong as standard 1/2" hex even with the hole through it.

Despite a horrific history final coming up tomorrow, I did some work today, and currently I'm expecting to make a 3/16" hole in the hex shaft for a custom shift rod with a diameter of 1/8". At some point I will run the shaft through Solidworks Simulation with these dimensions.