TAJ45
Silver $$ Contributor
Ok, have read everything, was reminded of a few points, learned a bit as well. Here is my contribution:
When setting compound, I've been advised by trng instructors, bosses to use 29.5°. So I did and have been. Probably hasn't made any difference from 29°.
When picking a thread up, I would take my clip board with scratch sheet, place it under the tool tip and use the white, light background to contrast the gap I was needing to adjust. Same when using a center gage (fish tail).
I have plunged w the cross slide when mat'l was tough then followed w my super slick hand ground HSS @ 29.5 when situation required. So many ways to skin the cat.
On occasion, the threads were subjected to inspection via optical comparator - govt nuclear components. This was for angle and finish. PD of course by Super Mic and wires.
I saw the split threads earlier and it seemed like angle was off as Dusty mentioned.
I remember a situation where a very sharp CNC operator had some threads that checked 100% ok w wires everywhere but the ring gage would not run the full 3.5".
He was tearing his hair out. I looked at it after he solved the mystery. The machine had a problem and was varying the lead minutely during the cut. Slick flanks but when you caught the light right, you could see a ripple in the 1.125 chased shaft. A head scratcher for sure.
PS. Just remembered: I have used a live or dead center tip to set my tooling before starting a job. If I needed an additional unplanned tool later in the process, I would blue a portion that was yet to be final cut and set to that light scratch mark. I dont remember reading that.
When setting compound, I've been advised by trng instructors, bosses to use 29.5°. So I did and have been. Probably hasn't made any difference from 29°.
When picking a thread up, I would take my clip board with scratch sheet, place it under the tool tip and use the white, light background to contrast the gap I was needing to adjust. Same when using a center gage (fish tail).
I have plunged w the cross slide when mat'l was tough then followed w my super slick hand ground HSS @ 29.5 when situation required. So many ways to skin the cat.
On occasion, the threads were subjected to inspection via optical comparator - govt nuclear components. This was for angle and finish. PD of course by Super Mic and wires.
I saw the split threads earlier and it seemed like angle was off as Dusty mentioned.
I remember a situation where a very sharp CNC operator had some threads that checked 100% ok w wires everywhere but the ring gage would not run the full 3.5".
He was tearing his hair out. I looked at it after he solved the mystery. The machine had a problem and was varying the lead minutely during the cut. Slick flanks but when you caught the light right, you could see a ripple in the 1.125 chased shaft. A head scratcher for sure.
PS. Just remembered: I have used a live or dead center tip to set my tooling before starting a job. If I needed an additional unplanned tool later in the process, I would blue a portion that was yet to be final cut and set to that light scratch mark. I dont remember reading that.