Does someone still have a threaded rod machine, to test?

Design of moving parts, and method of locomotion.
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Awesomeness
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Does someone still have a threaded rod machine, to test?

Postby Awesomeness » Thu Dec 09, 2010 10:13 pm

Airnocker brought up some questions about the precision and accuracy of threaded rod machines. I don't have mine anymore, but does someone have one that could run some tests?

Maybe cut out a 6" square a couple times, and compare the sizes of them? And how close are they to 6"?

I'm wondering how accurate the threads on the rod are.

Maybe cut a 2", 4", 6", and 8" square, and see if they are off by consistent amounts (such as 0.002" on the 2", 0.004" on the 4", and so on).

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beermkr
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Re: Does someone still have a threaded rod machine, to test?

Postby beermkr » Thu Dec 09, 2010 10:34 pm

Mine is pretty much dead on. I did some cutting and measuring to adjust my steps per inch number and I expect I am pretty close now. I also made delrin threaded plates which are WAY tighter tolerance than the normal nuts.
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Re: Does someone still have a threaded rod machine, to test?

Postby servant74 » Sat Dec 11, 2010 3:00 am

Beermkr,
Would you mind cutting a few squares and measuring them for us? ...

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Re: Does someone still have a threaded rod machine, to test?

Postby beermkr » Mon Dec 13, 2010 2:27 pm

I will try to get some cut this week. I will set something up to cut a nested set of 2, 4, 6, and 8 inch squares I guess there is no reason to cut all of them all the way through so I will only half cut the inside squares.

R/
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Re: Does someone still have a threaded rod machine, to test?

Postby airnocker » Tue Dec 14, 2010 4:26 pm

I do not believe I was questioning the accuracy of threaded rod machines, the do provide good accuracy when using 18TPI or greater but I was making a statement that they were not as simple to deal with anti-backlash issues compared to ACME Lead screws and their anti-backlash nuts.

I would be interest to know how those of you who are using threaded rods dealt with anti-backlash adjustments.
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Re: Does someone still have a threaded rod machine, to test?

Postby beermkr » Tue Dec 14, 2010 5:28 pm

I made custom threaded delrin blocks and axle grease to keep them lubed. I just recieved my DumpsterCNC nuts for the new machine. I have to say that my threaded rod machine works just fine. I expect to have to replace the blocks eventually but so far I have not seen any major issues.
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Awesomeness
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Re: Does someone still have a threaded rod machine, to test?

Postby Awesomeness » Tue Dec 14, 2010 10:57 pm


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Re: Does someone still have a threaded rod machine, to test?

Postby airnocker » Tue Dec 14, 2010 11:01 pm

Wow, that's really neat that you've had good results.
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Re: Does someone still have a threaded rod machine, to test?

Postby Awesomeness » Tue Dec 14, 2010 11:16 pm

I bet there was 0.005" of backlash, or something. But that's imperceptible without measuring it with a dial caliper. Things I made always fit together well. Really, 0.005" is the thickness of a sheet of paper, and it would be hard to tell.

I suspect, too, that since the backlash goes into all parts made on the machine, it will make all parts off by a similar amount. When you go to put those together, everything may fit ok because the 0.005" small block goes into the 0.005" small hole. So it may all be relative.

We'll see what actual tests show.


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