A Head Alignment Process for a PM1340GT

Thanks So Much. I will follow your procedure as outlined.
 
Question about run-out of the ground test bar.
After your adjustments you have zero run-out or equal movement both sides of zero?
 
Question about run-out of the ground test bar.
After your adjustments you have zero run-out or equal movement both sides of zero?

Correct - on my setup, I had equal movement on both sides of zero after alignment.

I will add a little to the explanation for others.

The precision ground test bar is trued up with no runout at the 4 jaw chuck. Without disturbing the indicator mounted on the carriage, you move the carriage down the bar and check the runout at the far end. If it's in alignment, any move off zero is exactly the same on both sides of zero. Any bend in the bar is irrelevant when using the RDM. However the bar should be precision ground and must be the same diameter end to end.

This is the beauty of the RDM technique. Your bar doesn't have to be perfectly straight. A tight tolerance on the bar's diameter is what counts.
 
I really don't remember - I think it was on the order of .002". It really is irrelevant though.

Edit: what's important is that it is the same on both sides of zero.
 
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Well not really though because it shows some skew in the chuck, no?
Mine is ~ .005"
 
Could be, but the tolerance on my ground bar is +/-.002" per foot.

Have you checked the diameter of your bar and the point of dialing it in at the chuck and then at the outboard point to make sure it is the same diameter?

If you bar is the same diameter, how about playing with rotating your bar in your chuck by 90 and 180 degrees and see what happens? May tell a story.
 
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