Custom Gearbox Without Automated Machining?

[asid61]

Originally Posted by FrankJ

Machinist were building gearboxes way before CNC and DRO although those are great tools if you have them. You can lay them out with a machinist scale and a scribe. Youtube is an incredible resource for this kind of stuff. Here a couple of videos comparing the different methods. I would recommend machining the side plates in pairs the whole match.

Hole layout part one

Hole layout part two

On youtube: mrpete222 has many great videos on old school machining. THATLAZYMACHINIST is another good source.

I love mrpete, but still strongly recommend against making FRC gearboxes with only prick-punch layouts. In the second video he compares the accuracy of three different methods (one of them being DRO) and he is still only getting around +/-0.005" on his holes- which is still better than the great majority of students will do. That kind of tolerance is unacceptable for even Vex gears. At the very least, use the mill's built-in dials to drill your critical holes like those for bearings.
This Old Tony is another good resource for machining.