Sieg SC4 Threading Dial

thingiverse

A Threading dial for a Sieg SC4 lathe - this has a metric 2mm pitch leadscrew, and the helical gear has been calculated to fit this perfectly. Only one mark appears on the dial, making it easy to reverse my lathe. I engage the half nuts when these 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. Then, I reverse the lathe, and re-engage the half nuts when the marks line up again. The body requires two 8 x 22 x 7 ball bearings (608-2RS) and a few 8mm shafts cut to size. If you're fitting this dial to an SC4 lathe, like me, you may need to drill and tap an additional threaded hole in the saddle of the lathe as the existing one is not suitable due to its proximity to the lead screw chip shield.