Boaring bar made by kenametal had a single set screw in it was rather amusing to watch it fail and Actually to be honest I never even stopped to consider that the motor shaft or mount could possibly be damage and it's an 8th scale mamba monster motor and my buddy had a similar issue with his mamba XL motor n pinion slipping so he bought a non hardened gear and drilled it out to have 3set screws grabbing the motor shaft same concept I use on my non hardened pinion...and machining the gear blank is easy the teeth not as much but it can be done And I would agree not all pinioned are made the same the one cheesy Lhs sold me a carbon steel pinion once as a hardened one or I should say tried to anyway I wa like bud no way is this hardened look at the color difference between this one that definitely is and the one that's not but I also feel like I can be more selective about what materials to use if I make my own