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Chasing a warp on two parallels


Jun 28, 2012
Mt Clemens, Michigan 48035
Each cross-feed stepover:
A large stepover puts a lot of wheel and pressure on the part, it also loads up a greater portion of the wheel and can reduces wheel RPM, all detrimental to taking a bow out of a part,
Not having a 50 or 25 millionth shim to go under a bow part one might grind an under-space set of two .500s and one .500050 set-on-blocks
For the other size, two .500 and one .500025
I have a notched long parallel that I grind in place so to advert any chuck wash-out, or if I have to run a part on somebody's grinder that I don't trust the chick being exactly flat.
A quick skin on that is quicker the qualifying the whole chuck.

Just a little heat swelling can make a part concave when it cools.
One often sees that on YouTube. The grinding has space between sparks, and then all of a sudden the sparks get close together-> that is heat swelling and will cause a bow in a part because the midsection of the part swells more (higher into the wheel)..

A hack method for 25 or 50 millionths is to set the part on a flat surface(not your surface plat) and with automotive wet abrasive paper by-hand push the part where it needs stock taken and take stock that way. at the center on one side, and at two ends on the other side.
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