03-14-2015, 06:50 PM
(03-14-2015, 06:16 PM)Mayhem Wrote: Thanks Ken - I wasn't aware that the anvil that has to change when you run the lathe in reverse to cut a LH thread with a RH tool?
Yes, and same for using a LH tool to cut a RH thread. The helix angle is inclined in the opposite direction, so you have to tip the insert the other way.
Or, just get the right tool holder. If I happen across the same tool in left hand, would be an SIL 0750 P22, I would grab it. For the more common 16ER size insert that can handle 8 to 72 TPI, I now have four external tools including SER 1000 P16, SEL 1000 P16, and the drophead (run upside down) SER 1000 K16D and SEL 1000 K16D. For internal I have 3 bars for 16IR, 1/2", 3/4" and 1", one LH bar 3/4", and some smaller ones for 6IR and 11IR inserts. I haven't got many inserts for the small ones yet because taps do 99% of the threads I need,
For the 16ER/IR tools I've added the full sets of 7 different anvils, so I'm ready for high helix angle threads, or really large fine threads. If someone needs a 3-start thread, I can probably do it with tools on hand.