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Author Topic: New Guy . . . Old problem??? - motors not turning  (Read 13034 times)

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Offline Hood

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Re: New Guy . . . Old problem??? - motors not turning
« Reply #20 on: February 26, 2009, 05:08:56 PM »
 What pitch ballscrews do you have? Do you have any gearing between motor and ballscrews?
Hood
Re: New Guy . . . Old problem??? - motors not turning
« Reply #21 on: February 26, 2009, 05:18:39 PM »
Hood,

Best I can tell the screws are 11 tpi (p=.0909).  Motors are direct coupled to these screws.

Matt

Offline Hood

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Re: New Guy . . . Old problem??? - motors not turning
« Reply #22 on: February 26, 2009, 05:22:21 PM »
Thats a weird one LOL, anyway at 11tpi that means you need to turn the motor 11 times to move one inch so 11 x 2000 = 22,000 steps per inch for motor tuning.
Hood
Re: New Guy . . . Old problem??? - motors not turning
« Reply #23 on: February 26, 2009, 05:31:46 PM »
Well, that's an improvement - but not there yet.  With 22,000 steps per inch G0 X10 moves X 5 - 7/16". 

Weird one - if you only knew what else goes on around here.  LOL 
Maybe I'm missing the obvious, is there a trick to calculating threads per inch?

Matt

Offline Hood

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Re: New Guy . . . Old problem??? - motors not turning
« Reply #24 on: February 26, 2009, 05:36:46 PM »
count them :)
Are they ballscrews? If so then get a rule or better a set of calipers and count how many there are to one inch.
Kind of sounds like your motors may be 9 degree steppers and that your screws could be 10TPI. Try setting to 40,000 in motor tuning.
Hood
Re: New Guy . . . Old problem??? - motors not turning
« Reply #25 on: February 26, 2009, 05:48:49 PM »
Count them - there's the problem . . . I'm a musician, I have trouble past 4.   ;D

At 40,000 G0 X10 gets me 8 - 1/4".   TPI is 10.  Based on your previous remarks, that must be a more standard tpi.  :)

Matt

Offline Hood

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Re: New Guy . . . Old problem??? - motors not turning
« Reply #26 on: February 26, 2009, 06:00:03 PM »
Something strange going on there, with your previous setting of 22,000 and moving 5.4375inches then setting the steps per to 40,000 you should have been 9.886inches.
Wonder if your problem is you are commanding a 10inch move, maybe you need to just stick below 4 ;D
Seriously though it may be you are losing steps, do a G1X10F10 and see how far it moves.

Hood
Re: New Guy . . . Old problem??? - motors not turning
« Reply #27 on: February 26, 2009, 06:11:57 PM »
The X axis seems happy at 64,000.  Not so for Y.  I'll try G1X10F10 in the morning.

Matt
Re: New Guy . . . Old problem??? - motors not turning
« Reply #28 on: February 27, 2009, 10:34:01 AM »
All axis are happy at 64000.  I am going to try some test runs to check accuracy.

At 64K G1 X10 F10 moves X 10"

-Matt

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Re: New Guy . . . Old problem??? - motors not turning
« Reply #29 on: February 27, 2009, 01:49:10 PM »
Something just doesnt add up but as long as you have things moving accurately then thats all that matters :)
Hood