I was reading up on lapping chuck jaws and came across the thread about using a brass bar and valve lapping compound to do the job. I want to make sure I understand the process before I try it.1) Get a brass rod 18" long and 1.25" in diameter. Face and center drill both ends.
2) Put a dead center in the spindle and another in the tailstock.3) Center both ends in the dead centers and turn a section long enough to make sure that it is perfectly parallel to where the chuck jaws would clamp onto it.
4) Tighten the jaws onto the brass bar to where you can barely turn the rod by hand with the rod still being held between centers.5) Using a screwdriver paste on some 320 grit valve grinding compound. Turn on the lathe at one of its slowest speeds and grind the jaws until the bar loosens up on the jaws.
6) Tighten the chuck jaws a little and grind again.7) Grind until you can see grind marks all along each jaw.
Chuck up a drill blank of the same diameter you used to turn the jaws and check for runout.
Is this correct?
Where do I get the adaptor to hold the dead center in the spindle? Would it be possible to use a smaller lapping bar and use a collet to hold the dead center with the draw bar and then just knock the collet out after use using a knock bar though the spindle?