- Joined
- Dec 25, 2011
- Messages
- 10,511
ON down OFF up is or at least used to be standard in the UK. No one else has ever mentioned this in discussions involving the motor switch mounted in the headstock of machines made prior to mid-1957 so probably your machine or at least your switch was made in Britain or was made here for Lend-Lease and either somehow came back to the States or was never sent to England.
Your assumption about not machining in Reverse is valid in most cases. You are just asking for trouble if you do turning or threading operations on parts held in standard threaded chucks. Exceptions are on grinding operations, on parts held in either collets or cutter holders, on parts held in 3MT arbor-mounted chucks where the arbor is held into the spindle taper by a draw bar, and on parts held in chucks that have an added device or means to lock the chuck to the spindle after the threads are seated. I have such a 3-jaw chuck. Which strangely enough was made in West Germany.
Your assumption about not machining in Reverse is valid in most cases. You are just asking for trouble if you do turning or threading operations on parts held in standard threaded chucks. Exceptions are on grinding operations, on parts held in either collets or cutter holders, on parts held in 3MT arbor-mounted chucks where the arbor is held into the spindle taper by a draw bar, and on parts held in chucks that have an added device or means to lock the chuck to the spindle after the threads are seated. I have such a 3-jaw chuck. Which strangely enough was made in West Germany.