Re-threading a Delta Lathe Spindle

The Spindle on my husband's new to him Delta floor model woodworking lathe xx needs some assistance, as I can't screw the Nova Chuck on his lathe. The Nova chuck works on my Jet Mini lathe with no issues, and I've used his Nova Chuck, was first to try it out.

rethreading a lathe spindle - FineWoodworking

I found this link on the FineWoodworking forum... since I'm in a machinist forum, would love to know the opinion of machinists on re-threading the spindle. I've only used hand taps and dies on tiny, tiny stuff like 00-80, and 00-90 threads.

I liked the dykem post in the finewoodworking forum, but would use a sharpie instead to find out where it is catching. I have lots of files, and am used to using files, and of course have a collection of riflers.

Do I buy a new 1x8 die?

HF

I have lots of files, and am used to using files

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Good!

Do I buy a new 1x8 die

Click to expand...

No.

Your sharpie idea will work, too.
As long as you can get a thorough even coat.
The problem with using it on threads is that that is difficult - fresh sharpie ink tends to melt off existing and can leave less than uniform coverage. Which is what is wanted to discover small dings and errors to file.

Unless you are using it to slather the chuck and look for marks on the spindle threads? This can work. It can also be ambiguous. Or it can sometimes reveal/accumulate on the area -around- the polished high spot.

However, you seem to already know what is necessary: 1.) even coating of some sort of indicator. 2.)skill/practice to understand what the indicating medium reveals 3.) tools (files) to deal with the revealed errors & a modicum of finesse to wield them.

There are thread files made specifically to address the problem of burrs/dings on threads. They often come with a different pitch on each side of each end (8 pitches). I've never used one. Generally use slim or X-slim 60deg triangular files, or handsaw sharpening files. There are You Tube videos on using them. But triangular files work fine.

Good luck!

smt

Simplest cure is to get a standard 1"x8 UNC Gr 8 nut,and screw it on with a wrench a few times ,and the hard steel will reform the burrs without making the fit any looser.

Thanks for the replies... will try something soon; it is a good test for skill.... my best file is a Japanese imported file purchased at the local woodworking store; hopefully it won't be a perfect fit! I will look through my triangle files instead.

HF

Thread files work great, just buy one with an 8 TPI included. I’ve used them to great effect on similar threads on plant machinery. They are really self-explanatory, just get one and you’ll see, trust me. Won’t take you more than 10 minutes.

Jeff

stephen thomas said:

There are thread files made specifically to address the problem of burrs/dings on threads. They often come with a different pitch on each side of each end (8 pitches).

Click to expand...

I've "lived by" my extensive collection of inch and metric "thread restorer" files for over fifty years.

Needed SELDOM, very damned seldom, actually.. but when you do need one, there is nothing better suited for the tasking.

Thread-Restoring Files – MADE IN USA | Jaw Manufacturing Co.

Crescent-Nicholson, Lisle, and others also list them.

flattened down, nicked or damaged threads should be addressed with the correct pitch thread file.

Yes, jeff and Stephen Thomas first mentioned using these.

It has to be the same thread pitch with it being fudged up or a little tight, as the thread file won't change the pitch(TPI). Perhaps the lathe spindle is 1-8 thread so the chuck also has to be that same 1-8 thread.

Every shop and every mechanic should have a set of thread files.

Yes, the thread file is only good for non-hard threads.
A simple file test is due before you try a thread file using a low-cost file.