Thread issue with QCTP adapter on 10x22 lathe?

matthewsx said:
If you aren't looking for "a little more work" I think you're in the wrong place ;)
Folks around here will use $10k worth of equipment and many hours of labor to produce a $2 part:laughing:

Do it right and you will be pleased with the result I'm sure.
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Oh, I'm not averse to going a couple of extra miles. My only issue is, at my current skill level, the question is being certain I can locate/drill/tap the holes within the required spec, and get everything else set up correctly. There are a few other details I need to figure out or learn how to do, such as transferring a ball oil port from the old sled to the new one. So next step is to spend some time with the QCTP and compound rest to get a better idea of how all the component parts play together.
 
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Learning this stuff is all about screwing it up and doing it over, better. No other way to get good at it, unless you have a pro looking over your shoulder. That's where we come in :cupcake:
We may not be pros but at least we're friendly. And oh so good looking
 
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markba633csi said:
Learning this stuff is all about screwing it up and doing it over, better. No other way to get good at it, unless you have a pro looking over your shoulder. That's where we come in
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Maybe what I'll do is take a good look at the QCTP, sled and compound rest, and then start a new thread on the replacement project, throwing out some questions on the way. Might do that either here or in the Beginner's section. Thanks for the advice!
 
Have you checked the pitch on the 8mm stud? 8 mm. is very close to 5/16". A 5/16 -18 thread would get about one thread in and jam.
 
I haven't read the whole thread so apologize in advance if I missed something. I've had similar situations in the past.

Question. Do you have a thread chaser set? It's not taps or die, they help clean and arrange existing threads. This could be the issue with your original grizzly post thread and I have had the same problem and not being able use it after a turn or two, those post's can take a beating with all the tightening and threads can get stretched. It's amazing what a thread cleaner can do and has saved me from a lot of problems. Using a tap or thread die is not suggested unless there's no other choice as it will remove material from the threads making it looser and weaker.
Second have you measured the thread pitch and major diameter to confirm it is a M8-1.25? They do make a M8-1.0 fine, which is not used often. And as mentioned above, it could be imperial 5/16"-18.

Before taking on a project customizing/altering your compound rest, I would first tackle trying to identifying and solve what the present issue is as an exercise before taking on customizing your compound rest. Having said, changing the thread post to the larger and stiffer 9/16-18 qctp is so much better, once you change it you'll never want to go back.
 
matthewsx said:
If you aren't looking for "a little more work" I think you're in the wrong place ;)

Folks around here will use $10k worth of equipment and many hours of labor to produce a $2 part:laughing:

Do it right and you will be pleased with the result I'm sure.


John
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thats SOP!!
 
You could take the hollow bolt down to your local (decent) hardware store and check it on their nut/screw checker to see if RJ's comments about 8x1mm vs 5/16-18 are true or not.
 
RJSakowski said:
Have you checked the pitch on the 8mm stud? 8 mm. is very close to 5/16". A 5/16 -18 thread would get about one thread in and jam.
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homebrewed said:
You could take the hollow bolt down to your local (decent) hardware store and check it on their nut/screw checker to see if RJ's comments about 8x1mm vs 5/16-18 are true or not.
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Thanks for the suggestions. I have one of those thread-checker sets, and tried the 5/16-18 on everything (the post on the Grizz lathe, the Grizz handle that screws onto that post, and the hollow bolt designed as an adapter). Nothing screws further than a turn or so onto 5/16-18.
 
When I got started with my g0602, I had a QCTP and adapter from LMS that resulted in a similar kind of setup. In hindsight, I wish that cobbled together mounting system had failed sooner than it did. What eventually happened, was the M8 threads just ripped out under the stress of trying to get that setup good and tight for a demanding job that kept knocking my tool post off angle. That hollow tube adapter setup just never was adequately rigid, although I had no basis of comparison, and did not realize it at the time.

The way I dealt with it was to go out and buy a real Aloris tool post. I was so sick of that import at that point. All in all, it makes me happy seeing the Aloris logo on my lathe, and I might talk myself into doing it again, but there is definitely a voice in the back of my head telling me I should have just bought the Aloris mounting stud. It would have fit the import QTCP, and the end result would have been virtually identical for like $65 instead of the $350 I laid out. The real improvement came with replacing multiple interconnected hollow nonsense with a big hunk of solid.
 
I used the M14 stud that came with my AXA QCTP and made a new Tee nut for my G0602.
 
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