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Author Topic: Random Loss X-Y axis  (Read 7053 times)

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Re: Random Loss X-Y axis
« Reply #10 on: May 04, 2011, 06:37:30 PM »
Driver test smooths out to almost no bumps after initial few seconds
Re: Random Loss X-Y axis
« Reply #11 on: May 06, 2011, 03:53:41 PM »

Could be a few things, noise and tuning being the top of the list. Can your drives accept differential Step/Dir signals? If they can consider making or buying line drivers to make the Step/DIir differental.
Is the error within the following error set in your drives? If its outwith then your drives should trip so if they are not then that would point to noise, if it is then it cold be tuning.
Hood

Hood,
We got it all worked out and my machine runs better than ever.
Thank you so much for helping narrow down the culprit.  
I contacted Hui at DMM Technologies. He
He is the expert on the retro kit I purchased from him.  He went the extra mile and... well he said I could post his findings.

So here it is:
Bare in mind Hui's English is getting way better,  he is very pleasant to work with and patient to listen and take the time to help.  Sometimes it takes repeating a sentence 2 or 3 time to break down the language barier.  


Hi Steve:
 
Thanks for calling me yesterday, it is good to have a discuss with you over the phone call, although my cellphone is not so clear voice.
 
I was using the oscilloscope to have a look into the step/dir signals from Mach3 while the number in the motor tuning for step/dir pulse
is being changed from 0 to 5.
 
Here are the results:
For the dir pulse, the number from 0 to 5 seems no meaning, the step pulse always keep 50us away from the dir signal's up/down edge.
 
For the step signal (normally be zero, will be 5V when there is pulse)
5V duration             Step pulse number
2.5us                        1
2.5us                        2
3.0us                        3
4.0us                        4
5.0us                        5
 
for the PC, the max pulse rate from Mach3 is 100kHz, 10us period, that means if the step high time is 5us, the low time will be 5us which
means enough space for low time.
 
So I suggest using: 5 for step pulse and 5 for dir pulse in the motor tuning settings. that will increase the signal width better for noise.
 
 
Very best regards
Hui Li
« Last Edit: May 06, 2011, 03:57:07 PM by retro-AC-Servo »

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Re: Random Loss X-Y axis
« Reply #12 on: May 06, 2011, 04:01:14 PM »
Good to hear you have it sorted, AC servos are great motors, dont think I would use anything else now :)
Hood