>Does any one know what the thread count on an infill plane adjuster is? I know there are two sizes but what are they and are they normal right hand thread? I bought a metal lathe last night and think I might give my hand at trying to make one for my next plane. Am I going to regret making this purchase? I lost sight of the top of the hand tool slope hit a bump and might have fallen over a steeper slope. If I have done something wrong I could just sell it and pretend it never happened.
>I'd read SMT's comments on adjusters before setting out on making up one of my own. Vlad Spehar posts a fair amount of information from SMT on his website
>Now you are in for it. Better say good bye to the wife and kids. This is a journey you may not come back from. Oops. Maybe you've got lathe knowledge and skills from earlier in life and it'll be no big deal for you.
What lathe did you buy and what tooling is attached? In particular, is there a thread dial? Let's hear some details.
The first thing you probably won't be doing is cutting threads unless you know a lot more than your comment suggests. Anyway, most of my infills have what amounts to square threads. Some look Acme to me. TPI and thread form is up to you or what you are copying. Don't expect anything standard.
I'm delighted for you...and a little frightened for you.
>I read your post thinking you were talking about the big brass screw in the lever cap. Your plans now seem sound to me. You'll use the lathe to machine the adjuster pieces and then standard dies to form the threads on those pieces. You'll also be using the lathe to put the knurl on the knob. Using off the shelf thread dies will be infinitely more accurate than anything most home shop guys can accomplish on a home shop lathe, I suspect. Sorry about my confusion.
>I don't know what all is with it. it is an old ACME looks to be in good shape There is some tooling not much a couple chucks various centers and gizmos and a box of dodads. I figured I could turn the shaft down to the two sizes I needed and then use a couple die to cut the threads? Quick simple Lazy. I know nothing about any thing just take a look at my woodworking. So it's not like using a tredal lathe for making chisel handles?
>The threads on the original (meaning pre-1922) Norris adjuster were 35 tpi and 40 tpi, as shown in the picture below.
This combination makes the action of the threads additive, rather than differential, and the result is a very coarse adjustment. After 1922, the design changed but the threading was still additive. Here's a picture of the newer design:
This threading moves the blade by .056" per turn of the knob, which is a lot, the same as a thread of about 18 tpi. The Norris-style adjuster made by Karl Holtey moves the blade about .013" per turn (~78 tpi), which allows fine adjustments to be made quite easily. Holtey uses differential threading, so that one set of threads advances the blade while another set of threads retracts it. Stephen Thomas tried an adjuster with an effective ratio of 128 tpi and thought it was overkill. He now uses 72 tpi. ( This is from a post on Badger Pond.)
If you want to know the exact combination of threading Holtey uses, I can find out. If I were to make an adjuster, I'd consider the style Stephen Thomas makes, which gives better control of lateral adjustment.
Let me know if you'd like further measurements or scans of the Norris adjusters.
>but, if your new at this I can suggest a copy of teh "The Home Machinist's Handbook" by Doug Briney. Lots of good metal head info in it for the beginner.
ISBN 0-8306-1573-3
Sounds like your sliding down both sides of the slope now. Watch your privates, that peak is aproaching fast!
>Ernie, I got to play with one of those years ago when I did some mechanic stuff and they're fun. If you have the room to keep it I bet you'll find hundreds of uses for it.(So will your friends)Keep it.---Jack
>The "two thread" approach (either additive or differential) also tackles another adjuster issue.
If you have a "one thread" adjuster (like later Stanley #60 1/2) you have to have a sliding fit in the traveller. This can (indeed) be made to have little lash, if precision made, but this is difficult and also vulnerable to wear.
By using a threaded contact between adjuster and traveller, the contact area is made using very refined techniques (threading has been much studied :-), and over a wide contact area.
I recently found this page, which might be of interest: these taps and dies have very fine threads (for their OD):
