Monday, October 9, 2017

Making an infill plane from scratch 14, depth adjuster.

My original plan was to make a Norris style adjuster for the depth adjustment of the blade. But after completing the rear tote, I discovered that on account of me making the handle as small and delicate as possible, I had also made it difficult to fit a regular Norris adjuster to the plane.

I have toyed with a couple of alternatives:
1) No depth adjustment mechanism, just the tried and trusted plane adjusting hammer.
2) Inventing a new type of depth adjuster.

Ref 1) This would enable me to just move forward and have the plane done in a relatively short time, but I would also risk becoming the laughing stock of the woodworking blogosphere, since I have earlier in this series mentioned that I was going to make a depth adjuster.
A positive thing would be that there is very little risk of messing up the plane.

Ref 2) I have sketched a couple of ideas, and even went as far as to begin work on the most promising of those models.
The best design sported a worm gear giving an accuracy of roughly 1/1000" for one full revolution of the adjustment screw.

Today I had to make up my mind about which route I wanted to take.
I looked critically at the screw holding the chip breaker, since that one was fairly large,and in turn that was causing the problem of an even larger retaining ring to move the blade assembly back and forth.
Very unlike my usual behavior, I decided that it might still be easier to turn a new screw for the chip breaker, and then go ahead with a regular Norris adjuster, instead of risking to mess up the entire plane in an attempt to make a supe fine adjustment mechanism.
So that ended up being the outcome.

My Norris style adjuster will not be used for lateral adjustment, since the rear tote is fairly thin on the top. So I will need a hammer to adjust it laterally anyway. But the depth adjustment will hopefully work.

The new design depth adjuster would have the depth adjustment screw going out the left side of the rear tote. This finger screw would activate a worm gear with a ratio of 30:1.
The worm gear would then drive a threaded rod with a retaining ring on it (just like a regular Norris adjuster). The threaded rod was meant to have a pitch of 1mm/revolution (M6) A bit finer than 1/4" UNC. (Maybe it is equivalent to UNF?)
So the math of the adjuster looks like this:
1 revolution of the finger screw = 1/30 round of the worm gear = 1/30 of 1 mm = 0,03 mm (1.2 thou)

Maybe I should try to make an adjuster like that one day, just for the fun of it.

Blade and Norris style pieces mounted.
Worm gear experiments above the blade.


  1. Wow, i admire your gusto, i would had called it quit without any adjuster :-)

    Bob and Rudy back. From the woodshop on base

    1. Hi Bob

      I was close to do the same, but I felt that I had more or less promised that I would make an adjuster, so I felt obliged to give it a try.


  2. I wish I could be of some help, but I've never actually held an infill plane, let alone used one. Nonetheless, yours is looking great. Good luck with the adjuster. If my opinion counts, I personally like adjusting planes with a hammer anyway.

    1. Hi Bill
      Thanks a lot.
      I am a bit uncertain if I will regret fitting an adjuster, if the rear tote breaks - then I will be more than a little upset.
      If the adjuster doesn't work very well, I will always have the possibility to remove it and adjust the blade with a hammer.
      I guess that I am a "mechanical" kind of guy, because I really like mechanisms that will do something.

      So I'll just continue with the Norris adjuster even if it might not be the smartest move.

      I have never tried or seen an infill plane prior to building this one. So I hope it will work well, especially given the number of hours that I have put into it.
      I kind of doubt that it will work any better than a standard Bailey plane, or a Lie Nielsen etc. But if nothing else it can look good.


  3. Hammer adjustment would have been fine, but I'm enjoying what you're coming up with whether it works or not. That worm drive sounds really cool, although having to move the blade very far could get old. Looks amazing, especially for your first go.

    1. Hi Jeff

      Hammer adjustment can be really accurate, but I like the adjustment mechanism for something like a smoothing plane.

      The very slow motion of the worm drive was also part of what held me back.
      I think the Norris adjuster will turn out OK.
      It will be interesting to see how the plane will perform once done.