Quote Originally Posted by Derek Cohen View Post
Patrick, I think that you are confusing matters. I have not said anything about razees. I simply stated which type of scraper plane was more ergonomic, a high sided coffin smoother with a vertical blade vs a low angle BU jack (with the same cutting angle) which is pushed from low down.
My point was that if height-of-effort really mattered, then those planes would have been made as razees instead of coffins. It doesn't, and they weren't.

I've long since learned to very skeptical any new "innovation" that was actually both widely known and feasible all along. Low center-of-effort is one of those - everybody has known for centuries (literally) how to implement that. The fact that they didn't consider it worth the bother says something very important (and as I said, engineering analysis agrees - there is no significant difference in pushing effort).