I am mostly done with my retrofit of a 13x40 import lathe and have everything up and working other than the spindle encoder. I am wondering if someone could help with a basic circut to use the infared emitter and detector part# 276-142 from radio shack . They are relativley cheap and avail just about everywhere

I started to go the way you are going.
I ended up with - http://www.cnc4pc.com/Store/osc/product_info.php?cPath=25&products_id=129
                         http://cnc4pc.com/Tech_Docs/C3_5_WG.pdf
It's all together and works PERFECTLY.
Just a Thought

thanks , would have ordered one of those a week ago had I know it existed , hopefuly it will be here in a few days , ready to see this machine cut threads