"John Thompson" wrote in message
What what happens is that the machinist "rocks" the part on the grinder
table, trying to find the concave side and putting it on the bottom. He
then shims it with thin stock under the high sides until it doesn't rock
anymore, then turns on the magnetic table.

Don't see why you can't do something like that with a board in a planer.

John

Different tables.

Locking the material with a shim on a stationary table is much easier than
trying to shim a 6' board that is going to move on a short table under the
stationary cutter.

If you have a consistent cup, it may work, but if you have some odd twisting
at different points, it is going to be much more difficult to get it right.
Only a couple of feet of the board is supported at a given time.

The shorter the board, the easier it is. The thicker the board, the less
likely to get pressed down if cupped. I've tried taking very light cuts on
some pine boards with cup and had no luck. It is just too soft and easily
flattened by the rollers to work properly. On 8/4 oak, I had no problem.

I don't have a jointer yet and I've gotten by, but there have been times
that life would have been much easier with it. I've also passed on some
cheap wood that could have easily been used with a jointer, but would have
been a PITA with just a planer.

No matter how bad a piece of wood may be twisted, someone here has been able
to get it perfect with an Xacto knife and beer can opener, but it sure is
easier with the right tools.
Ed

http://pages.cthome.net/edhome