John Wilson’s Adjustable-pitch Plane
If you had only one bench plane, it would be nice if that plane could do both roughing and smoothing chores.
Woodworker John Wilson tackled that problem in our April 2011 issue with his adjustable-pitch jack plane, which can be switched from 45° pitch to 52° pitch in less than a minute. I’ve had the plane here for more than a year and I was personally surprised how easy the tool was to use and change back and forth.
What is even more clever about the tool is that Wilson added an adjuster to the tool that works quite well. I shot some video of the tool in use today so you can see how simple it is to change the plane over from 45° to 52°.
If you build this tool, here are a couple details you should think about.
The adjuster really works only when you are seeking to increase the depth of cut. That is because the adjuster can only push the blade down. It cannot pull it back.
To reduce the depth of cut, I unscrew the adjuster a few turns, hold the plane upside down and loosen the main thumbscrew. Gravity pulls the iron back a bit against the adjuster. Then I can advance it to where I need it.
You have to plan carefully the size of the mouth if you want it wide open for rough work and tight for fine work. As Wilson built the plane, the mouth doesn’t change much when you switch pitches. If you want to tighten the mouth for smoothing, you’ll want to make a thicker wedge. Make it the same 7° pitch, but make it thicker with a blunt apex.
All in all, it’s a fun tool to use, and making it lets you dabble with a little simple metalwork.
— Christopher Schwarz
More on John Wilson
Wilson teaches lots of classes on toolmaking at his shop in Charlotte, Mich. A class with him will overcome your fear of heat-treating metal.
Kara Gebhart-Uhl wrote this nice profile of Wilson and his shop, which you can read free on our web site.
We now carry plans and supplies for John Wilson’s Shaker boxes in ShopWoodworking.com.
P.S. The music in the video is called “Through the Grassy Hills” from freeplaymusic.com.