Sieg SC4 Threading Dial

A Threading dial for a Sieg SC4 lathe - this has a metric 2mm pitch leads crew, and the helical gear has been calculated to fit this

There is only one mark on the dial - as I can reverse my lathe, I engage the half nuts when them marks align. When I reach the thread relief on the part I'm threading, I disengage the half nuts, stop the lathe and wind the tool out. I then reverse the lathe, and re-engage the half nuts when the marks align again.

The body requires two 8 x 22 x 7 ball bearings (608-2RS) and a some 8mm shaft cut to size.

If you're fitting to an SC4 you may, like me, need to drill and tap an additional threaded hole in the saddle of the lathe as the one that is there is no good as it's too close to the lead screw chip shield.