Thread: Squandering Clearance

A problem any owner of a small mill faces is a limited useable working space.

I had bought a 30 taper boring head arbor from CTC a while ago with the intention of making my own compact boring head for my mill. Last night I was fooling around with my Craley boring head and I thought I should remove it's 2 Morse arbor and modify the CTC arbor to suit. I turned down and screw cut it's 1 1/2" threaded nose to suit the Craley's 7/8" x 18 TPI thread and fitted the head.

Installed in the mill I realized I was wasting about 12mm of precious vertical clearance. The Schaublin collet chuck shown has a driven flange 8mm thick and the spindle drive dogs engage no more than half that thickness. While I could have thinned the flange a couple more millimetres, I stayed with 8.

The steel CTC use is tough stuff. The interrupted cuts cost me a couple of insert points. Still, a worthwhile modification which will do the job until I find the mythical Wohlhaupter UPA2 with an ISO30 arbor.

BT