stoneaxe
Stainless
- Joined
- Mar 2, 2010
- Location
- pacific northwest
The collet holder I am making is to fit an old VN C taper- The mill spindle has been ground and is within .0002" runout.
The toolholder has an accurate taper and the 8 degree ER recess was bored and faced on the mill.
Now it is on the lathe to turn threads for the collet nut. As the nut has a taper for the collet, the effort is to get the threads very accurate, so the nut pulls up square.
The face is running .0003" out. The concentricity is within .0002. The piece is parallel with the lathe centerline on one axis and within .0002" when rotated 90 degrees.
The toolholder is in a four jaw chuck, and there are two .005" paper shims to get it aligned, on one side and end of the toolholder shank.
I can measure closer (barely) , but can't physically adjust the part any closer-
Are there techniques for making minute adjustments on this sort of thing?
I have never tried to work to this sort of accuracy before. And considering what this is for, it is likely good enough. Chasing accuracy is a good illustration of the Law of Diminishing Returns....
The toolholder has an accurate taper and the 8 degree ER recess was bored and faced on the mill.
Now it is on the lathe to turn threads for the collet nut. As the nut has a taper for the collet, the effort is to get the threads very accurate, so the nut pulls up square.
The face is running .0003" out. The concentricity is within .0002. The piece is parallel with the lathe centerline on one axis and within .0002" when rotated 90 degrees.
The toolholder is in a four jaw chuck, and there are two .005" paper shims to get it aligned, on one side and end of the toolholder shank.
I can measure closer (barely) , but can't physically adjust the part any closer-
Are there techniques for making minute adjustments on this sort of thing?
I have never tried to work to this sort of accuracy before. And considering what this is for, it is likely good enough. Chasing accuracy is a good illustration of the Law of Diminishing Returns....