Originally Posted by EXT2Rob

Doing a once over on my HoBao Hyper TT I found the front diff input cup was worn. Both slots looked like a letter P. Lots of slop. And, I didn't have a spare. What to do? Race day is tomorrow!

​​​​​I found an allen wrench to secure the drive cup to, and put it in a bench vise. I used a hacksaw to cut new slots 90* from the worn ones, and called on Dr.Emel and his cutting wheel to clean and widen the slots. Works great. Maybe found a way to extend the life of the cups!