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Author Topic: Driver Testing?  (Read 4158 times)

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Offline SMA

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Re: Driver Testing?
« Reply #10 on: December 19, 2011, 08:01:03 PM »
Yes I have tried swapping motors.  It was both Z and Y.  I have used coding as a workaround but would like to finally track down the problem.

  One thing I did notice is that I have backlash unchecked.  Wondering if that is the issue?  Talked to the fella who made the machine and he feels it may be a Mach Version issue.  He had tested on Version 2 and I am running Version 3.

I have gone over mechanical so many times.  No binding, motors sound great and machine is very smooth.

This is a screen shot of my backlash config (or lack of it).

S



Offline Hood

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Re: Driver Testing?
« Reply #11 on: December 20, 2011, 02:54:54 AM »
Leave backlash  disabled at the moment as it will just add to the confusion if its not set up right.
You say you swapped motors, did that solve the problem for the Z?
What hardware do you have? Drives etc.

Hood

Offline SMA

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Re: Driver Testing?
« Reply #12 on: December 20, 2011, 03:45:46 AM »
Hey Hood,

Backlash is not setup.  The designer of the machine informed me that he had backlash enabled when the machine was tested and is going to send the parameters that were setup at time of testing which, I am told, the machine was running perfectly and was not losing position at all.  The big issue I believe is not owning the computer that the machine was setup with orginally.

This has been an ongoing problem.  The machine preforms a move called the crossover.  After machining one side of the surfboard the machine crosses over to complete the other half.  When it did this Z would end up about 2mm lower than it should be cutting one side of the board thinner than the other.  Swapping drives did not change a thing.  I added a G28.1 command that would of course send z back to home switch and "find itself" and then move down to cut the board.  Essentially I coded out of the problem for now.

Y loses  itself in the same fashion.  About the same amount out as Z was lost.  I have added a 28.1 that has reduced the issue to a manageable point but again would like to find what the issue is.

I swapped drives (only x has been consistently spot on) and quadruple checked any kind of binding issues.  I did fresh installs of MACH and just recently optimized the system as well as updating drivers (which did improve the driver tests).

There are "sensitivity" settings on the drives which can be increased.  This is about the only thing I have not toyed with but will be going there next if all else fails.

I believe the drives are Gecko's.  I will investigate the details and post asap.

Thanks once again !

S

Offline Hood

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Re: Driver Testing?
« Reply #13 on: December 20, 2011, 04:28:50 AM »
Ok now you menton surfboards I remember the macine in question :)
Sadly I cant remember all the steps you went through before, I am wondering however what you have the pulse widths set to on the motor tuning page?
Hood

Offline SMA

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Re: Driver Testing?
« Reply #14 on: December 20, 2011, 04:39:45 AM »
It has been a bit of a slog. I keep finding work arounds but I can't help but want to understand what the root of the issue is.

I have the motor dir pulse at 3 and direction at 2. This is the case for all axis.

Offline Hood

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Re: Driver Testing?
« Reply #15 on: December 20, 2011, 04:58:00 AM »
Ok that will likely be fine.
I seem to have it n my head that the axis setup on your machine is not really conventional, could it be that the two axis you have issues with have the most weight on them?
I am wondering if it is your motors are just on the small side for what they are meant to be doing. The builder may well have tested but how good did he test? Do you know if he ran similar jobs to you are doing and was getting the accuracy?
Hood

Offline SMA

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Re: Driver Testing?
« Reply #16 on: December 20, 2011, 05:24:25 AM »
If I remember correctly the builder used some weights to simulate a load on z. X and Y are both horizontal axis.   Z must overcome the strongest forces.  U could very well be right about undesized motors or gearing of  ?  These are steppers at 3:1 I believe.  I will check in the am as to some more precise information on gearing, motor type, and driver type.