Single point threading

[camdigger]

There are many ways to skin this particular feline, and almost every lathe operator has a different opinion. Also, the more experience the guy has, the stronger the opinion. Funny thing about experience, there are guys out there with 30 years of widely varied experience who take on different work constantly, and the others who have 1or 2 years experience 30 times.

Here is a bit of a mind bender on lathe threading.... https://youtu.be/Z-dqOi_z5bk

Joe does have some very strong opinions on thread gauging. He has a point WRT interchangeability. What say all the seasoned guys aboard here?

[digr]

Interesting I knew it could be done that way but never tried it,it would sure be faster instead of using back gear when threading up to a shoulder. As far as the the wires go I think they would be a waste of time I always use a nut and never had a problem. IMHO

[milomilo]

Originally Posted by digr

Interesting I knew it could be done that way but never tried it,it would sure be faster instead of using back gear when threading up to a shoulder. As far as the the wires go I think they would be a waste of time I always use a nut and never had a problem. IMHO

I do not use wires either. A new nut has always worked well for me. My best advice is cut threads down to where the nut only goes half way on, use a file lightly to take off burrs at the top of the threads and then keep your depth the same and run cleanup passes till the nut goes on smoothly. Has always worked well for me without over cutting the thread depth.

[toprecycler]

I do like Joes videos. I have picked up a lot of tips from him.

I did get my boss to buy me a right handed threading tool so I could do this. I did it for a while, then I stopped and went back to the way others in the shop do it. Was easier than always explaining why I do it do different. But, there are times that I am tempted to go back, or do it his way.

But, that being said, a lot of older (like my south bend) lathes probably can’t do it, because they can’t run the spindle in reverse. So it really depends on work you are doing, and the lathe you have to use.

One of the first things I had my boss buy was a set of thread wires. He looked at me like what are those, and why do you need them? We never needed them before.

But, I have used them several times, and has been a big help.

Sometimes we get a cylinder rod from a customer that will tear their own cylinders down and fix it themselves. They just send us the rod to make a new one. But they do not send the piston or piston nut sometimes, so I have to determine what the thread is and match it. We usually use a test but and single point to when it fits, but when I am sending a part 100 miles away, I want to be sure that I made that “metric” thread to specs, and know it will fit. We have a good selection of test nuts, but not every size , and we do not want to wait to order one that might cost $50 too.

Of course, the other problem I always worry about, is by not having the nut that they are going to use, is I do not know the condition of the nut, so I am taking it for granted that it is a standard nut.

I have recut threads on a rod end before to save the from remaking entire rod, and have made a custom nut to that thread. But that is usually because the customer wants to save money and wants the quickest cheapest fix.


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[digr]

I usually mike a bolt to get the O.D.

[greywynd]

I use both thread wires and nuts, depends on what the job is. The last thread I cut was a few months back, not even sure what the part was for. Just got a sample part with damaged threads. Figured out what the thread was, and had to use wires to cut it, was my only option, and cut it to specs.


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[ShawnR]

Thanks everyone. It sounds like I was on the right track. Yesterday, it looked pretty good, so I backed off the live center, tried the nut, no go, so set the live center again and did a few more passes. It was here that I wondered when I should stop? Trial and method works for me. I have seen the wires, and that interests me. I doubt I will ever do anything in my backyard shop that will require that accuracy, although I like the procedure. Seems very....methodical...

At one point yesterday, I had to disconnect the carriage before I was done, think not planning ahead. I did not have clearance diameter small enough to start thread unless I started cutting so wanted to use the other cutter to reduce the diameter at the start. To replace the thread bit, I very carefully positioned the carriage manually by turning the chuck by hand, with carriage lock in place and setting slides, and was able to continue on to the finished product that I posted. Would not want to be doing that often but it worked out. I learned a lesson, make sure starting part is large enough (long) and thin enough that I will be able to finish the cut without impinging on the material.

I will check out some of Joe's videos.

Thanks
Cheers,

[camdigger]

Shawn. In among all Joe's other videos, he goes through a single point thread repair. In that video, he goes through how to pick up a thread using the cross slide and compound slide on work where the set up has been disturbed ( half nuts disengaged ) or at the start of a job.

[Norm W]

With a screw on chuck that technique could get exciting. Particularly at the speed he is running. I can picture the chuck chasing him around the room.

[Ironman]

I noted that this was his first video, in the safety warning.

You can't go too far wrong following Joe Py