Making threading tools?

[Jim Underwood]

Anyone make threading tools?

I'd like to get started threading, but don't have the $$$ to buy some tools outright, but could possibly spend a little for fabricating some.

I see an article on another forum where a guy filed some cheap chisels into threading tools, but that sounds like a lot of work. I'm just wondering if anyone has made some by soldering on, or making handles for taps or dies- or something similar.

[Jason Christenson]

I have absolutly no answer to this question, but I hope somebody does. I've been wondering about that too.

Jason

[Rich Souchek]

Jim,
Yes, people do it.
What I have seen is them take a bolt or nut with the desired thread spacing on it. Grind out several sections that are about 3/4" long by 1/8" to 1/4" thick and about 1/2'" tall. The 3/4" x 3/16" long face should have the threads. They welded the steel bar to another to create the thread chaser, just like one can buy from the ready made tool manufacturers.
Rich S.

[Pete Jordan]

Jim,

I bought the threading tools and rented the movie and still didn't have much luck. At our next turning meeting, someone is going to show us how to make a threading jig using a router and I have seen the results and they are great. I will post info after the meeting.

[Jim Underwood]

Oh yeah. There's a tutorial and plans to make that threading jig that uses a router on the internet somewhere. The late Jean Michel came up with the one I'm thinking of. Unfortunately I think he passed away before he came up with the one that would make threads different from the 8tpi jig he designed first. But keep us posted on that, I was wanting to make that jig myself...

I've been wondering if I could just silver solder a threading tap to a rod and grind it appropriately to come up with a good threading tool. Sounds as if I could, from the description Rich gives. I'd have to buy a Mapp gas torch, and some silver solder (there went the budget ), but it certainly should be doable. Thanks for the push in the right direction.

[joe greiner]

I tried using a thread-chasing mechanic's file that Rich mentioned, and had the same luck as Pete. It likely takes a lot of practice to cut them that way, even if you scribe a first few turns by hand to assist guidance.

I'm part way through building a jig somewhat like Jean Michel's, but based on a cross-slide vise to carry the threaded spindle. BTW, I found a pdf file for his that included a 1/2-13 spindle in a tapped hole in the 1-8 rod carrying the workpiece chuck. Seems to be absent from the web site now. And having made an auxiliary spindle for a bench mandrel, I found that tapping the hole in the 1-8 rod takes a lot of care to reduce runout to an acceptable value.

Another variation, more like what I'm planning, is (or was) here (I think; I copied the url into a saved text file):

http://www.wood.org.nz/thread1.php

If gone, Google ["dick veitch" woodturning].

{OK; no sweat. Still there as of right "now."}

Bonnie Klein sells a device like this, and also someone else (Can't remember his name). Both somewhat $$$, though.

Aside from all that, what's so bad about 8tpi? Except in very hard wood, finer threads seem like an invitation to disappointment.

Joe

[Jim Underwood]

If you've still got that copy of the PDF file, I'd love to have it. I've downloaded the other one and have been eyeballing it for a while to see if I could figure a way to change the thread pitch.

Most times people recommend 16 tpi as being optimal. 8 tpi is a little coarse for small boxes and urns. You have to pay attention to the wood you thread though...

[joe greiner]

If you've still got that copy of the PDF file, I'd love to have it. I've downloaded the other one and have been eyeballing it for a while to see if I could figure a way to change the thread pitch.

Most times people recommend 16 tpi as being optimal. 8 tpi is a little coarse for small boxes and urns. You have to pay attention to the wood you thread though...

The pdf file of Jean Michel's updated threading jig is 821 Kb, 11 pages; too big to upload, and somewhat selfish to e-mail to only one; and a complete PITA to broadcast e-mail even if I knew how.

However, I've just learned that I can extract individual pages. The first page is 77.7Kb, within the upload limit, I think. I'll do the rest and verify all are within the limit. I found no copyright notice, so should be legitimate to post. This may take a day or two to fit in with other demands.

Here's another one that I found:

http://homepage3.nifty.com/manasan/e...iy/diygr56.htm

He made the cross-slide from scratch in aluminum. Note the scale attached to one of the carriages to control position.

The 60-degree symmetrical cutters are somewhat expensive, about $25 IIRC. Grizzly has 60-degree dovetail cutters, H2955 - H2961, which could be used with the workpiece at 30-degrees offset angle. The smaller sizes should be adequate for thread cutting, at about $12 max.

A one-tooth cutter could also be made from an Allen wrench, ground at 60 degrees symmetrical, for {parallel-axis} work. The grinding should include proper rake and relief angles, which might take some experimentation.

Joe

[joe greiner]

Update on my previous post.

Extracting individual pages from the parent pdf file was not perfectly successful, as several of the pages are still above the upload limit.

I took a screen shot of the region which seems to be significant to your interest, Jim. Attached as jpeg image. Consider the following alterations, though:

1. The large threaded rod must match your chuck or faceplate (should be obvious). Some lathes use a larger or smaller spindle thread. The length shouldn't be taken as gospel; use whatever works.

2. The 7/8" setback should be less than the depth of the inside thread on your chuck or faceplate, so that the hub bears against the large nut; the outside end of the threaded rod thus need not be square. The other end, however, should be square to mate with the smaller jam nut (not identified in the pic).

3. I'd substitute the single large nut and setscrew with double nuts. This might better reduce runout.

4. The smaller threaded rod is best selected from standard UNC thread sizes. Fine threaded rods may be awkward to obtain at retail. For the range of interest, standard threads are 1/2-13 and 3/8-16.

5. The 49/64" depth of the tapped hole seems somewhat short, unless you use a bottoming tap. I've had better luck with a single tapered tap, with the hole depth increased to accommodate the tapered part of the tap. An actual contact length of 1.5 times the nominal rod diameter should be sufficient (i.e. not including the addition for the taper).

Drilling and tapping the large threaded rod is best done on the lathe, with the power off for tapping. The tailstock live center engaging the hole in the aft end of a tap wrench can facilitate alignment; I set the tap very slightly loose in the tap wrench to accommodate longitudinal movement. You may be better off having this piece worked by a machinist, though.

I hope this helps, and bear in mind I'm not a real machinist.

Joe