[Maniac_Mechanic]

I am a senior FIRST member. My school is fortunate enough to still have a metal shop. I know the traditional argument is that a lathe should be purchased before a mill, but let me give you my experience.

We definitely use our milling machine a lot more than the lathes. Cutting keyways is not a chore for the lathe. Milling slots in tubing for retracting arms is not for the lathe. Many of the round things we use in robotics can be purchased easily.

Custom shaft couplings for different sized shafts- if you don't have these on hand, they can be made on a lathe quickly and for a fraction of retail price. Saving time is huge bonus in this game.

If you do lots of work with gears or anything that spins, drilling true holes in the center of something must be done on a lathe for the close tolerances of gearboxes and such.

I have a lathe at home. I've done threading work on it for robotics parts. You need a lathe for cutting obscure thread sizes.