With my lathe open, I took the opportunity to help out a commercial shop owner. He'd bought these two 1" diameter two-flute shoulder mills, but they aren't available in the 3/4" shank size he needs to use in the live tool collet chucks on his CNC lathe. I offered to turn down the shanks for him because he's very busy and the only machinists he has capable of such a job are busy running jobs.
I mounted my 12" independent 4-jaw chuck and gripped the working (insert pocket) end using copper shims. It took over 45 minutes of work to get the ground, somewhat hard shanks to run true from end to end. I pray it didn't move while turning through the Weldon flats with a TPG322 grade VC610 Valenite cermet insert. One done, I'll put the inserts in it and check it for runout in my mill with an R8 collet and later in my lathe using a C5. If good (less than .0005" runout), I'll do the second one. Given that they cost over $340 each new and can't be returned once modified, it's a one shot deal!
![[Image: IMG_20140703_201321971_zpsmz4dbulh.jpg]](http://img.photobucket.com/albums/v466/kenm10759/Dads%20shop/IMG_20140703_201321971_zpsmz4dbulh.jpg)
I mounted my 12" independent 4-jaw chuck and gripped the working (insert pocket) end using copper shims. It took over 45 minutes of work to get the ground, somewhat hard shanks to run true from end to end. I pray it didn't move while turning through the Weldon flats with a TPG322 grade VC610 Valenite cermet insert. One done, I'll put the inserts in it and check it for runout in my mill with an R8 collet and later in my lathe using a C5. If good (less than .0005" runout), I'll do the second one. Given that they cost over $340 each new and can't be returned once modified, it's a one shot deal!