Where Can I Get Thread Grinding Wheels?

It isn't as stable as cutting normally so a little caution is warranted, but it works well. You still need a small counter bore to have clearance for the tool, but that should cause no problems.
 
Poor dog. :cry: Mike

dave_r_1 said:
...the tool crashed into the piece then broke so the tip embedded in your chest, meanwhile, the part got out of balance, causing the lathe to shake violently and tip over onto you, then when your wife heard your screams and came to help, just as she reaches you, the motor shorts 220V to the frame, killing both you and your wife. a week later, the dog is dead because it hasn't been fed.
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Having never done thread grinding but have watched it done. I can say it is usually done on specialized machinery. I have done a lot of thread milling on a Bridgeport when I made molds for plastic bottles. As far as a lathe though I will undercut at the shoulder and if I am not real easy that day I will do as Jim suggested and turn the cutter upside down and turn the threads outward. The only time I ever threaded up to a shoulder without an undercut was on a Hardinge Lathe with the automatic threading attachment. It was very scary the first time watching that tool come so close to the shoulder before popping itself out automatically.
 
Thinking out loud, but I saw some pictures of a Quick-action tool post holder. It in effect is a lever that you actuate to quickly remove the tool from the work. On board my ship, the US Cape Cod A-43 we had a small Hardinge lathe. It was used for threading lengths of rod. I say this because it had something similar to this. As you approached the end of your thread, you pulled a lever near the tool post, then your left hand was on the motor reversing lever. One pulled the tool away, the other reversed the saddle traverse. Made VERY quick work of threading...Now the picture I am referring to has MUCH less travel but the same principal. If made with enough travel, one could avoid that crash to the part and yes, most that say they have never crashed like that have a nicely selective memory or little "experience"... :)
 
dave_r_1 said:
killing both you and your wife. a week later, the dog is dead because it hasn't been fed.
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I just had to laugh at this...you don't know how many times my wife has said....but what will happen to the dog? LOL
 
Getting the wheels isn't going to be a problem but getting the dresser to form them could get expensive. The wheels do wear and need to be dressed.

"Billy G"
 
For what you want to do i would have a cbn wheel built, that way the form is there already, you only have to clean it with a armature stick. There not cheap but to have Norton or Carborundum build a special one for you would not be either. The normal dia. for a threadgrinding wheel is 18- 20"x 3/8" or 7/16" for j&l thread grinders. Worked for Besly taps and gages for 43 years
 
Wreck™Wreck said:
Please explain this.
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Limited spindle speeds, table servo/stepper accuracy, way accuracy, etc. doesn't stand out to me as a very good idea for thread grinding. Plus grit on the machine, etc. I think thread milling, then using a brass lap to clean up the threads is a much better idea. Just my $0.03 (inflation sucks)

OP has revealed his intentions, to use a toolpost grinder. I believe that to be a much better idea.
 
I have an import lathe, the feed is not easily reversible and the spindle turns way too fast for cutting threads. I use something similar to this.

http://www.bedroom-workshop.com/tools-lathespindlehandcrank/0toolslathespindlehandcrank.html

I can thread as close to a shoulder as the bit will allow. I also don't have a threading dial, so I never disengage the feed, I just crank in the opposite direction back to the start.

As to threading in reverse, if you have a threaded chuck, you need to take real light cuts.
 
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