Originally Posted by HuFlungDung Vibration when finish threading can be a problem that will pop up for anyone, at various times. I think the typical solution is to dispense with the light finishing passes, and thread 'like a man' 
If the light finish pass is mandatory, then play with the infeed angle parameter if you are using an automatic thread cycle. You would be striving to make the chipload differ on each side of the tool. Or, take the last finish pass as a G33, but vary the Z start point by a thou or two either side of the center, so that the tool is cutting on only one edge at a time. |
This problem has come up before. The problem then was loose spindle bearings. I am not seeing a problem with the finish itself, it just rattles when making the finish cut. It progressively get's worse each pass. According to the operator this problem has been getting louder and louder with each week.
They are using a M54 then a G92 thread cycle(I don't know squat about programming). The insert is not a chip breaker, so the chips are stringers. The finish cycle is cutting both sides of the thread. I don't believe they have this problem on any other machine, including the 2nd Mazak they have. I believe they are all programmed the same. Maybe the "finish pass" is hacking off more than a usual finish pass would. The vibration does not occur when rough cutting the part.