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.