Banebots 42mm gearbox: Recommendations for use

[ZZII 527]

Originally Posted by eugenebrooks

Tool steel is too brittle for this application.
You should be using 4130, 4340, or 4140.

Eugene

My earlier testing leads me to believe that the original carriers in the 42mm gearbox are tool steel. They are not hardened, however, so at worst I am making spares of similar hardness to the original. I've had some success, though, with hardening and tempering the A2 tool steel back to a Rockwell C40, the very low end of its useful hardness range, and I'm going to do some testing .

I'm not disagreeing with you, though; I also think steels you mentioned are more appropriate for this part. The steel I'm using is most noteably used for knife blades... I'm using what was quick and readily available, for now. (McMaster sells 5/32" stock of tool steel, but unfortunately not 4140.) I'm not recommending that anyone go out and buy a plate of tool steel for these, but if teams try hardening the original carrier and it is the same as ours, they will see tool-steel hardness. I'd like to see if the low end of that range can work.