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rough motion
« on: December 10, 2009, 02:56:51 PM »
I have an old motion master I am converting for my use I have granite devices drivers on fanuc motors 1000 steps to the mm. resolution. at 2000mm/min I get pretty good motion above that I get hammering in both the x and y axis . including jog. I have tried tempest too and get very smooth motion just too slow to be viable for production. I cleaned out the startup and several other non essential windows functions. it helped but not the final solution. I assume that  if this is a windows issue that a smooth stepper or another motion card would take care of my problem .

I would like to get input from some of you who have had to deal with these issues, the computer I am running the machine with is an IBM p4 with more than the minimum requirements per the mach 3 specifications.

Offline Hood

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Re: rough motion
« Reply #1 on: December 10, 2009, 04:11:55 PM »
If you have electronic gearing try that and see if the motors are fine at higher speeds, if so then sounds like the pulse stream from the PP is your problem.
What kernel have you got Mach set to?
Hood
Re: rough motion
« Reply #2 on: December 10, 2009, 04:50:48 PM »
I have the kernel set at 100k but I have tried it at lower speeds as well. I'll try it with the gearing suggestion and let you know,

Thanks

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Re: rough motion
« Reply #3 on: December 10, 2009, 05:00:05 PM »
Most parallel ports are not happy at 100KHz and the majority seem to behave best at 45KHz or less. It certainly sounds like the pulse stream is your problem and if so then the SmoothStepper will help you with the added benefit that you will have plenty of overhead to get your motors to full speed without having to resort to  electronic gearing.
 On my lathe I had to use 45KHz and 2:1 electronic gearing and the fastest rapids I could get were 3,200mm/min. I could have increased the electronic gearing to get faster but I wasnt happy with the slow speed motion with any more gearing. I put the SmoothStepper on, set the gearing to 1:1 and could get rapids of 20,000mm/min. I settled for 10,000mm/min in the end as the lathe is heavy and having rapids that fast were just too frightening ;D

Hood
Re: rough motion
« Reply #4 on: December 10, 2009, 05:47:38 PM »
I followed your suggestion and cut the resolution by 5 and it was a world of difference. I'll place my order for a smooth stepper right away. I only switched one axis and the I left. it was still clunking a bit but it is lighter than the other, so it's less obvious.

Thanks again, I'm sure I'll have more issues before it's all over

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Re: rough motion
« Reply #5 on: December 10, 2009, 05:50:38 PM »
:)
Re: rough motion
« Reply #6 on: January 29, 2010, 09:18:33 PM »
Hood, just thought I'd let you know, I ordered my smooth stepper, it arrived as I left for a trip to a trade show, and I just now had time to set it up. I rescaled to 1:1 and the motion is now very good. I also have tried the tempest planner and the motion was phenomenal, I haven't cut any thing but air yet but it's looking good. so far it appears all of my motion problems were related to the wonders of windows.

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Re: rough motion
« Reply #7 on: January 30, 2010, 03:35:17 AM »
Good news :)
Hood