Blade radius on a low angle smoother

[Lewis Moon]

Do you radius a blade on a LAS differently than on a regular bench plane? I ask this question because it seems that the effective radius (as presented to the wood) would be larger on the same blade bedded at 12 degrees than it would be on a blade flipped over and bedded at 45 degrees.
You van visualize this by cutting a circle in a piece of paper then holding it in front of you at 45 degrees then moving it to 12. At 0 degrees it would become a flat line.

Am I over thinking this? (of course I am....:rolleyes:)

[Wilbur Pan]

There was a huge and unnecessarily overheated discussion on this fairly recently on the FWW Knots forum.

Basically, to make a very long story short, it looks like you need to put more of a camber on a bevel up blade than a bevel down blade to get the same effective camber. The bevel up vs. bevel down issue is the key, not whether it is a low-angle vs. standard plane.

(Sorry for not referring to the radius, since the geometry part of my brain has gone AWOL today. But hopefully you get my meaning.)

But the easy way not to over think this is to put a camber on your blade. If you are leaving plane tracks, put more camber on until they disappear. ;)

Of course, now Derek will come along and express this idea way more eloquently than I can.

[Randy Klein]

I started a thread (http://www.sawmillcreek.org/showthread.php?t=61788) awhile back about this same thing. If you scroll down some I compiled a spreadsheet that calculates how much camber is needed given the bedding angle, width of the plane blade, and desired shaving thickness.

Short answer, yes, more camber is needed.