Plane geometry?

[Artie Hall]

I've always wondered about this. Since the bottom of a plane is perfectly flat, and the blade extends out the bottom, wouldn't the entire rear section of the plane be wasted? Or, wouldn't the plane ride on the wood at a cocked angle? Am I missing something here?

[Joel Goodman]

I believe that to some extent the plane does sit crooked on the wood but -- as the shaving is so thin it's not an issue. A powered jointer where a much larger amount of wood is taken off with each pass needs the infeed and outfeed tables at different heights.

[Mike K Wenzloff]

Not missing anything. The plane is riding on 2-3 points of contact, depending on the plane, sole length, plane flexibility and blade projection.

That doesn't address the graphic, which isn't quite how a plane lays upon wood in use depending on where it is in the cut.

Funny how unlike a plane is than a powered jointer, isn't it.

Take care, Mike

[Artie Hall]

Thanks guys. And you've cleared up one more thing that I didn't even ask . . . I've obviously got my blade set too deep. This would help to explain why I'm having so much trouble making smooth cuts.

Let me try this again . . . a little at a time.

Thanks;
Artie

[Will Blick]

Good thinkin Art.....

as mentioned previously.... if a hand plane took deep cuts, the rear end of the shoe would lower / raise with the blade... ... just like a power jointer....

But since the shavings are so thin, usually less than .008", it makes more sense to keep the surface entirely flat, otherwise the rear / front shoe could get out of registration and no longer sitting on the same plane. (plane as in geometric, not hand plane :-)

To make your sketch more exact, have the rear end of the plane sit on its center for the 3rd point of contact...