Rob

Off to share.

For the record, the scrub planes made by Lie-Nielsen and Veritas (Lee Valley) both come with blades that have a 3″-radius camber. I use the same Ulmia wooden scrub plane that I bought at least 30 years ago. The plane Ulmia/E. C. Emmerich currently makes, available from Lee Valley, looks just the same, including the shape of the blade. I checked my blade against a circle drafting template – the radius is 1 1/4″. That plane has served me well, and I’ve never made a significant change in the camber because it does what I want it to do.

It is all a matter of what works for you, in the woods you are using, in the tasks you are doing, to make the things you want.

Rob

I first reshaped the camber on the blade of my scrub plane to a 6″ radius. previously it was at about 3″ to 4″ radius which I found to be too extreme. With this blade properly sharpened I could reliably take shavings of 0.025″ thickness, however 0.020″ was notably easier and more practical for me. I can take shavings of 0.035″, however this was more effort than I was comfortable with and the blade tended to back up up even with considerable tension on the “screw” on the locking lever – Stanley No. 40.
With a Stanley No.5 blade sharpened with moderate camber, I could take shavings 0.012″ to 0.015″ in oak or walnut without undo effort. In other words the bench didn’t walk all over the shop.
I set up the No. 4 smoother with sharp blade and virtually no camber, shavings of 0.002 to 0.003″.

The corrected camber on the scrub plane was the missing element for me. With the setups described I feel much more confident in hand planing to reduce stock thickness.

Thanks for your tips – they led me to look closely at the scrub plane setup. I have previously been disappointed with the scrub plane results. The wood looked like a plowed field and way too much tear out to correct with the jack plane and smoother. I may push the camber radius to 8″ or 9″ to see how that goes.

I set my initial setting with the visual method as you describe, and then adjust the lateral by trial and error on an 3/4 inch edge of scrap. I like your method using a small block on edge. I will try that, looks quick and very accurate. Thank you again for the detailed explanations and really good pictures.

Pascal.

For final finish smoothing, think: sharp, very little camber, and thin shavings. Depending on the wood, the shavings are likely to be in the range of one or two thou in say, walnut or cherry. But pay attention to the resultant surface more than the shavings.

If you are trying to remove bulk thickness by hand, my first suggestion is to read this:
http://www.rpwoodwork.com/blog/2009/04/26/which-machine-first-and-why/

If you still want to remove bulk thickness (e.g. 1/8″ – 1/4″) by hand, don’t worry about the surface quality at the start. Consider starting with a scrub plane, which has a very large blade camber that takes very thick shavings. Work diagonally across the grain. It works fast but leaves a rough surface with tearout. No problem, that will disappear later in the process.

Then work the surface with the jack plane, again diagonally. Take thick shavings at first – as thick as you want to get the job done faster. Just leave enough material to later get past the tearout and roughness. Then decrease to thinner shavings as you approach the finished dimension. This will give a better surface and better accuracy in dimension and flatness.

After you’ve done a few boards this way, go out and buy a DW735. Better yet, add a Shelix cutterhead. Or consider the new Rikon helical planer. Life is short; you’ve got things to build.

Rob