QCTP Stud Upgrade

One of the things about my lathe that has always made me feel a little iffy was the QCTP stud. From the factory, it was a very anemic M8, that I’ve broken several times over the years. While taking some heavy cuts during a recent project, it looked almost as if the tool was tipping down because the stud was stretching under the load. I’ve learned from past experiences that I usually have another project or two before the stud gives up the ghost. This time around I decided to upgrade the stud to something with more longevity, instead of turning a replica of the inferior original.

I Originally considered an M14 stud, as the QCTP body had a big enough bore to support it. However after thoroughly examining the top of the compound, I decided M12 would be a good compromise between stud strength, and maintaining the structural integrity of the boss on the top of the compound. The stud is made from 1144 Stressproof, a material I’ve really come to enjoy working with. The accompanying Flange nut is made from annealed cold rolled 4140.

Reference:

• StudDrawing.pdf
• NutDrawing.pdf