Haha, yeah I know this is very not ideal. I'm working with a lot of spare parts trying to do the best I can.
I got a 1/4" carbide 4 flute bit (extends about 3/4" past collar), 25,000rpm air spindle (self regulating so i cant adjust its RPM), moving at 8mm/s. The fixture is about 7ft away from the robot so not max reach but not very close.
I'm about to get a 2 flute 1/4" carbide bit though.