Quote Originally Posted by M250cnc View Post
But can you hold the piece to be ground on a magnetic chuck with only light magnetic force so as not to distort the piece to be ground. Then clamp to an angle plate to get it square.

Can you take a CUT of 0.000005" yes that's not a mistake, on the lathe with a toolpost grinder, can you get a part of 6" x 18" flat with a tolerance of 0.0001"

If you can then yes you can do surface grinding on the lathe.
I'm not saying it will be as good as a lathe, of course not. If it was you wouldn't have a surface grinder!

You can take pretty small cuts though. The dials on my lathe are graduated to 0.001", you're cutting a 200th of that so put the top slide at an angle of arcsin(1/200)=0.29° (ok that's tricky to set) to the face. Clearly in practice that method has limitations - if you want to take a reasonable amount off then you're going to run out of travel and have to keep setting it.

There was a surface grinder at school, rarely used but useful when it was. One thing they did with it was to turn the old blades from the power hacksaw into parting tools for the wood lathe.