that's PRECISELY why I can't see how a plane can make anything truly
FLAT. A jointer wouldn't if it was set up like a plane. So what are we
missing? Or is the emperor buck naked again? g

dave

Richards wrote:

Bay Area Dave wrote:

I was thinking about the difference between a jointer (powered) and a
plane. A jointer has the outfeed table level with the blade so that
as the work passes over the blade and onto the outfeed table, if the
operator uses good technique to keep the board flat on the outfeed
table, the board pretty much has to come out FLAT.

A hand plane on the other hand isn't built that way. It has a
projecting blade. So unless the sole of the plane is extraordinarily
long, how can you get a perfectly machined straight board? Just for
grins, I was using a tiny hand plane to plane the edge of a board and
found that no matter how hard I tried, the small plane "unflattened"
the straight edge I started with. The more passes, the worse it got.
How long of a plane do you need to get a perfectly flat result on say
a 2' board? a 6' board? Is it MOSTLY technique, or do you have to
have a reference straight edge and keep checking your work constantly
as you plane? OR do you just take a few light passes over an
essentially flat board to start with, and know that it is flat? In
other words, when I use the jointer, I KNOW it's flat. I don't have
to check it. Can I do the same thing with a plane, or do you have to
stop, eyeball it with a reference straight-edge, and then touch it up
an little here, a little there?

Lay it on me, WW gods!

dave

You've made a very good point. If the blade projects beneath the plane,
the piece of wood that you're working on will never be perfectly flat
because the reference surface is not the same as the cutting edge.

To cut the wood perfectly flat, it seems that the plane should be
divided into two separate pieces. The part of the plane that is in
front of the blade could be raised to the height of the cut desired.
The part of the plane that is behind the blade should be set so that the
blade and the sole of the plane are at the same level.

It might help to visualize a router table set-up as an edge jointer. To
avoid snipe, the outfeed fence and the cutter are in line. The infeed
fence is moved back a little (the depth of cut desired). Couldn't the
toe of the plane be thought of as the infeed fence on a router table and
the heel of the plane be thought of as the outfeed fence?