Having turned, milled, annealed and hardened and tempered, I now need to add cutting some spur gears to my CV.
I have a mill and decent rotary table, so I'm assuming that I just need to buy the appropriate gear cutter and work out the "angle of dangle". This, like most of the things I do, will be fairly rare event. The design I'm currently working on suggests I need to make two 12 tooth and two 24 tooth module 1 gears cut with a 20deg pressure angle (that is to say bog standard stuff - but given my hobby is learning to make things, buying them misses point!).
However, one question I'd like some help with is the material to use - the gear chain of events is a 12 tooth spur cut in EN8 and hardened will drive a24 tooth gear on a countershaft. The countershaft also has a 12 tooth gear which then drives the final 24 tooth gear, to achieve a 4:1 reduction. This is being used to drive the valve timing cam in a 15 cc model engine (don't worry about 4:1 and four stroke -it's a trick I found on t'internet). Given I want minimum weight and to minimise gear noise what materials can I use in the gear chain after the driver spur (typically running at 5000rpm)?