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Author Topic: CSMIO-IP/A and max velocity setting?  (Read 6373 times)

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Offline Davek0974

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CSMIO-IP/A and max velocity setting?
« on: June 29, 2016, 08:57:41 AM »
I'm going through the settings on my bench setup of ac servo drives and the CSMIO-IP/A controller with Mach3.

I have steps per set as shown for my leadscrew/drive connection ratio but how do you calculate max velocity - It seems that if it is too high the drive faults on ePid error, too low and the 0-10v output does not reach 10v so velocity is wasted/lost.

How do you calculate the correct velocity to give 0-10v output or does it not work that way??

Offline Hood

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Re: CSMIO-IP/A and max velocity setting?
« Reply #1 on: June 29, 2016, 09:54:51 AM »
The setting you have in your servo drive for the RPM at 10v is the number you use.
So for example, you have your servo set to 3000rpm per 10v and you have a 2:1 ratio with a 5mm pitch screw.

3000rpm /2 (gearing) x 5mm pitch,  Velocity in Mach would be 7500mm/min


Hood

Offline Davek0974

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Re: CSMIO-IP/A and max velocity setting?
« Reply #2 on: June 29, 2016, 10:06:48 AM »
Ah, thats interesting then as that is just what i tried, it seems I have a DAC offset so if it set max RPM it works perfect in one direction (negative offset) but in the other direction (positive offset) it faults out with ePid error.

I Have to reduce max el to something like 7550 to allow it to run in both directions without fault.

I doubt whether i'll be running 7500mm/min rapids though on an old mill ;)

Offline Hood

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Re: CSMIO-IP/A and max velocity setting?
« Reply #3 on: June 29, 2016, 10:16:47 AM »
Never had that issue, both drive and axis/spindle set up that way on the Chiron and it is fine either direction.
What is your tuning like?
Do you have too small of a following error set?
Hood

Offline Davek0974

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Re: CSMIO-IP/A and max velocity setting?
« Reply #4 on: June 29, 2016, 10:34:37 AM »
disclaimer - Don't forget this is all on the bench so no load etc on motor. :)

I have a max follow error set of 10,000 in pid tuning, using the pid tune jog buttons, if i set max el at 98% it all works well and the Max I accumulator bar graph shows just two blocks.

If i increase to 99% it faults out when the Max I accumulator tops out.

I have no idea what the Max I accumulator is telling me though???

The value limit is set for 1000,000 in Max I Acc.

This is with max vel set at 7620 in Mach3

Offline Davek0974

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Re: CSMIO-IP/A and max velocity setting?
« Reply #5 on: June 29, 2016, 10:46:38 AM »
Just been playing again, its the max following error topping out that causes the ePid fault, at 98% vel it reads about 500 or so, at 99% it just goes up and up until the limit trips.

Any help :)

Offline Hood

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Re: CSMIO-IP/A and max velocity setting?
« Reply #6 on: June 29, 2016, 01:43:24 PM »
Ok just to be sure, you have the rpm for 10v set in the drive and you have the Vel in Mach set up to be exactly the same or rather you have the Vel worked out from that same rpm?

500 following error with how many steps per unit?

I am still a bit worried about you not being able to tune the servo drive, it is the first drive I have ever come across where there is not an ability to tune manually and yours doesnt even seem to have an autotune function.

You could try altering the accumulator, think I messed about with it a bit and found I got lesser errors when it was actually topping out on a rapid.


Hood

Offline Davek0974

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Re: CSMIO-IP/A and max velocity setting?
« Reply #7 on: June 29, 2016, 02:07:32 PM »
The drive is pretty much as delivered - you just set the motor designation in the parameters and thats it it seems.

Steps per was calculated from 10,000 pulses from encoder, 2:1 ratio and 5.08mm pitch screw.

I will try reading the drive manual again but its heavy going ;)

Offline Hood

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Re: CSMIO-IP/A and max velocity setting?
« Reply #8 on: June 29, 2016, 02:13:35 PM »
That is   a high following error then as it equates to 1.27mm

I got a manual for drives that are on eBay Uk, not sure if they are the same as yours or not but that manual has a manual tuning section. If they are the same let me know and I can pass the manual on, heres the ebay link.
http://www.ebay.co.uk/itm/201609613935?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Hood

Offline Davek0974

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Re: CSMIO-IP/A and max velocity setting?
« Reply #9 on: June 29, 2016, 02:24:40 PM »
Thanks Hood,
different drive, may be similar inside but connectors are different.

I need to do a tune with a load on the motor i think, it behaves differently with a finger on the shaft but that gets a bit painful after while ;)

Hopefully not too long before I can do a lash-up on the machine and see what happens.