[JohnToner]

This was the first time I tried turning on the 1100. I have to make a quantity of stud bolts, 1/2x20 L.H., 1.725" long. One segment is 1.000" long followed by a 0.625" shoulder that is followed by a 0.500" segment. I clamped a 1/2" shank tool holder with a carbide insert. I turned 5/8" 4140 to the appropriate dimensions running at S4000, F20. Flooding with Mobil 766. It was a cakewalk. Next weekend I'll be turning the LH threads on each end using a 1/4 carbide thread mil. Never done thread milling before, so it should be interesting. I'll practice on some cut-offs first.

[popspipes]

This was the first time I tried turning on the 1100. I have to make a quantity of stud bolts, 1/2x20 L.H., 1.725" long. One segment is 1.000" long followed by a 0.625" shoulder that is followed by a 0.500" segment. I clamped a 1/2" shank tool holder with a carbide insert. I turned 5/8" 4140 to the appropriate dimensions running at S4000, F20. Flooding with Mobil 766. It was a cakewalk. Next weekend I'll be turning the LH threads on each end using a 1/4 carbide thread mil. Never done thread milling before, so it should be interesting. I'll practice on some cut-offs first.

I face off 4130 tubing and part it off in the lathe, this may be similar to 4140, but machining it is a breeze. It will harden if cut with an abrasive wheel though, I also buy 3/4" x .035 wall and swag it down so it forms well too, good stuff but a bit pricey.

[CadRhino]

Very nice.
Were you hand coding ur using a cam program?
I assume you were using lathe tool holders clmped down for your lathe operations?

This was the first time I tried turning on the 1100. I have to make a quantity of stud bolts, 1/2x20 L.H., 1.725" long. One segment is 1.000" long followed by a 0.625" shoulder that is followed by a 0.500" segment. I clamped a 1/2" shank tool holder with a carbide insert. I turned 5/8" 4140 to the appropriate dimensions running at S4000, F20. Flooding with Mobil 766. It was a cakewalk. Next weekend I'll be turning the LH threads on each end using a 1/4 carbide thread mil. Never done thread milling before, so it should be interesting. I'll practice on some cut-offs first.

[JohnToner]

Cad,

Yes, I manually coded this as I do with all my projects. Since I'm not milling any compound curves, this has been a non-issue. The tool holder I used was a 1/2" shank lathe tool clamped in my vise. I don't remember the insert model and I'm not in my shop now, but it's almost square and slopes downward (negative?), This a.m. I ran some QC tests to see if a 1/4" solid carbide could thread mill at S4000 F30. For anybody who might have been wondering bout that, it failed. Two seconds/inch didn't seem that fast, but I guess combined with the helical motion, it was a little overly aggressive. As soon as I can replace the threadmill, I'll try again at F10 and three passes down to the minor dia. instead of foolishly trying to do it in a single pass. I do have a 1/2x20 LH die I could use, but I have a lot of these pieces to make, so thread milling seems the way to go. This was my first attempt, I mean QC test

[CadRhino]

You will no doubt get it worked out. That is impressive that you code by hand. I have lathe tools for threading and want to try it.

Cad,

Yes, I manually coded this as I do with all my projects. Since I'm not milling any compound curves, this has been a non-issue. The tool holder I used was a 1/2" shank lathe tool clamped in my vise. I don't remember the insert model and I'm not in my shop now, but it's almost square and slopes downward (negative?), This a.m. I ran some QC tests to see if a 1/4" solid carbide could thread mill at S4000 F30. For anybody who might have been wondering bout that, it failed. Two seconds/inch didn't seem that fast, but I guess combined with the helical motion, it was a little overly aggressive. As soon as I can replace the threadmill, I'll try again at F10 and three passes down to the minor dia. instead of foolishly trying to do it in a single pass. I do have a 1/2x20 LH die I could use, but I have a lot of these pieces to make, so thread milling seems the way to go. This was my first attempt, I mean QC test

[JohnToner]

I learned out of necessity - couldn't afford software. My "Cad" is a pencil, square, a ruler, and a blank sheet of 8 1/2 x 11 not that Chinese 10 1/2 dreck. My backup "Cad" is a napkin and a ball-point pen. No Cam or post needed! Manual coding isn't that difficult as long as compound curves aren't required. The basic movements are up/down, left/right, to/fro, and combinations thereof. Just tell the machine what you want it to do and it will usually comply. When you have a little spare time, try it on some scrap.

[CadRhino]

There is no way I could hand code a threadmill routine unless I has years to perfect my Gcode knowledge.
That said I sure it is empowering to know the code as well as you do.

I learned out of necessity - couldn't afford software. My "Cad" is a pencil, square, a ruler, and a blank sheet of 8 1/2 x 11 not that Chinese 10 1/2 dreck. My backup "Cad" is a napkin and a ball-point pen. No Cam or post needed! Manual coding isn't that difficult as long as compound curves aren't required. The basic movements are up/down, left/right, to/fro, and combinations thereof. Just tell the machine what you want it to do and it will usually comply. When you have a little spare time, try it on some scrap.

[JohnToner]

I have to admit that it was a learning experience that resulted in scrapping two 80% AR lowers and a dozen endmills plus one threadmill.

[kirk_wallace]

Thread milling a thread is just like cutting an arc with a Z parameter added.

Cuts arc:
G0 X 0.000 Y 1.0000
G0 Z 0.0000
G2 X 1.0000 Y 0.0000 I 0.0000 J -1.0000
Attachment 261434

Cuts one circle:
G0 X 0.000 Y 1.0000
G0 Z 0.0000
G2 I 0.0000 J -1.0000 P 1
Attachment 261436

Cuts one helix:
G0 X 0.000 Y 1.0000
G0 Z 0.0000
G2 Z -0.2000 I 0.0000 J -1.0000 P 1
Attachment 261438

Thread milling a thread just requires putting in the proper number of turns and how far to go in Z, so could be coded by hand using a bit of math and Machinery's Hand Book. (although this wasn't coded by hand)
Attachment 261440

[kirk_wallace]

As for testing, I use the screen plot and simulator to cut electrons, or cut air on the machine, or I make machinable wax from left over candles (4 to...) and #2 ice cream buckets (... 1 by weight).
Attachment 261448
Attachment 261446

[JohnToner]

Except for the single pass and F30 part, my code was Ok. I tested with 1/2" doweling, but my feed and DOC were too much for the 4140. I just ran in two passes and F10 w/o problem. Fortunately, when I broke the threadmill, it was on a scrap piece of 4140, not the actual parts. I'll try one more run with a piece of scrap before running the actual parts. I like the idea of using candle wax. Much better idea than using wood. Some stores still sell paraffin for home canning. But since most of today's women don't know how to can, its becoming a lost art.