Need a way to turn a 30 tpi screw.

[earlgo]

Harold:
I used both the thread micrometers and the thread wires, and in my humble opinion the thread mic for small threads is a pain in the tookus. However holding 3 each .020 wires was not a walk in the park either. You mentioned an easier way to hold thread wires a few conversations ago. Will you please refresh my memory? TIA
--earlgo

[GlennW]

I put one wire in my mouth.

Hold two wires on top of the threads and pin them there with the micrometer.

Then insert the third wire below the threads and close the micrometer on it.

You have to be able to operate the micrometer with one hand.

The wires need to be free to seek their own position against the threads.

I didn't have a third hand to operate the camera while insterting the third wire with my left hand...

[BadDog]

With a rag or towel beneath to catch the not uncommon dropped wires. I see in your picture that you do the same.

[GlennW]

Forgot that part!

There's nothing more fun that trying to find a wire in a chip tray full of curlies.

Thanks!

[JackF]

Thanks Earl.


Jack.

[Harold_V]

Earl,
Glenn provided the exact answer I'd have provided. It's proven to be a very fast and easy way to apply the wires, which I have used for days on end in my younger years.
Pitch mic?
I've tried them. Rather spend my time kissing a hog. Don't like 'em, and can see no good reason to own one. The best investment, assuming one has need, is a nice set of proper wires. They're not cheap (but man, oh man, are they nice!).

Do pay particular attention to not restricting the wires in any way. As stupid as it may sound, if they are applied to a thread and are not dead parallel, it's possible to achieve an erroneous reading. There's a strict mandate that they not be restrained, especially for calibrating plug gauges (used to be done with proper wires and a supermic). Some folks place them in an eraser, or even tape the ends---neither of which is acceptable.

In keeping with the comments about dropping a thread wire. You'd think that those nice, straight wires would stand out, but if you drop one in a chip pan with chips, they seem to become invisible. I can recall spending the better part of an hour looking for one one time. It was one of a set of three, precision thread wires. Worse, it was needed NOW, not when a new set could arrive. That experience taught me to clean out the chip pan if I was going to use thread wires. That's a whole lot faster than finding one, which is much like a needle in a hays stack.

I like the towel idea, assuming the pan isn't filled with chips and oil. That could prove to be just as annoying, although one would likely enjoy success just placing the towel on the lathe bed (and hope a wire isn't flipped in to the pan).

H

[earlgo]

Look back at page 4 of this thread and my setup does not have a lot of access as Glenn shows. But I was able to take the blank out of the lathe for checking. It still was a PITA to use the thread mic. However, I did get similar results with the mic and the wires. I must confess I did not have commercial thread wires, but 'found' a suitable substitute in the household inventory. (Ball headed sewing pins are accurately made, straight and easy to find if SWMBO is not looking.) Using the formulae in the Machinery's Handbook, I was able to calculate the PD for the 30tpi and the 'over the wire' measurement. The formula allows the use of a different wire diameter than standard, whatever that is. Still, measuring the pitch diameter of such a small thread was a bit time consuming.
Thanks for reminding me how it is correctly done.
--earlgo

[JackF]

Thanks to all who have contributed to this thread. I hadn't considered it would turn into such a tutorial. Thanks again and especially to Earl.


Jack.

[JackF]

Hi Earl, got the package yesterday afternoon. When I opened it I got a very welcomed surprise , thank you so much for the two books. I'm always looking for more information on firearms and especially on firearms I own. Just a little side note; I have a Stevens High Power model 425 lever gun that I acquired after my Grandfather died. I haven't found much history on the gun but I remember in the early 50s my Grandfather had a Shooters Bible? or Gun Digest? that featured the 425 and other fancier models based on the 425. I always look for the books at gun shows but have never for the right book. Maybe someone here would know more about the gun or maybe even own the book in question.

I screwed the blanks into the rifle this morning and they are a perfect fit. I will finish them up in a few days and post a pic.

Thank again,
Jack.

[earlgo]

Jack, glad they fit. My apologies for being so persnickity about being sure of the 30tpi, but I am of the persuasion, "trust, but verify".
Glad you are happy with the books. They would have been dumpster fodder in a few years. For the rest of the fellows, they were Volume I and II of James Grant's Single Shot Rifles. Enjoy.
--earlgo

[JackF]

Earl, here are the screws installed in my two Stevens Favorites. The gun at the top is the one I recently bought at a auction. It had the original screw that I used to determine the specs for the new screws. That screw had damaged knurls so I ended up using both ends of your blank. I turns out that each rifle needed different length screws which was fine as you gave me plenty of thread to play with. However I didn't get them both to seat at the same depth when finished but both will work as these are not are not museum pieces, just wall hangers. Thanks again for all your work Earl.


Jack.

P.S. The guns are sitting on my new Polaris. This will help this 75 year old with his scouting and hunting activities, and hopefully help with future packing out duties. My wife keeps telling me I am to old to do this anymore.

[earlgo]

I would like to see the pictures, but they haven't shown up yet. Please try again.
I am glad they fitted and you were able to make new TD screws from the blank.
--earlgo