Wiley Horne -- So. Calif.
>Gentlemen:

Just received a plough plane of'n the bay. Stupid me, I didn't ask the seller if the depth stop mechanism was working. It ain't--threads stripped. So this plane has become a project.

Facts. It's an A. Mathieson and Son plane (Glasgow & Edinburgh vintage). Wedge arm. Actually what attracted me to the plane was how perfect the arm wedges and main wedge are.

But anyway, the depth stop is the familiar one that has a brass thumbscrew which turns a steel drive screw. Down in the body of the plane, this steel drive screw is threaded into a brass plunger. The brass plunger has a steel shoe on the bottom, which alights on the work when you are at depth. As the brass thumbscrew is turned CW or CCW, it pulls or pushes the brass plunger up or down, raising or lowering the plunger/shoe assembly.

Now the steel drive screw is in great shape. But the matching threads inside the brass plunger are stripped useless. Someone forced this thing so badly, that the drive screw slides easily in and out of the plunger--the threads are not close to engaging. I'm searching in the UK for a replacement part, but realistically that's not gonna happen. So am trying to figure out if there is a fix using the original parts as much as possible.

What the heck is this steel drive screw? It mikes 0.290" major diameter, the pitch is right at 1/16", or 16 threads per inch. It's a pretty deep thread--I estimate the minor diameter is about 0.20".

What to do? In a perfect world, there would be a way to drill out the stripped brass threads in the plunger, fill the hole with round brass stock, re-tap and re-thread to match the drive screw. (There isn't enough width in the plunger block to accommodate a threaded insert.) But I can't imagine finding a tap or an insert to match that drive screw.

A crazy idea...It occurred to me that maybe I could buy some brass shim stock, cut the right-size piece of it and work that piece into the stripped recess in the brass plunger, with some adhesive behind it. Then run the steel screw in, and let the screw cut its own new threads in the shim stock lining.

Can any of you folks follow this?? Any thoughts on how to fix this depth adjuster would be appreciated. Yeah, I know the plane will work without it.

Thanks,

Wiley