Rls encoder and vfd calibration

All things related to the Centroid Acorn CNC Controller

Moderator: cnckeith

nicolasjolliet
Posts: 56
Joined: Wed Mar 18, 2020 4:15 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: 0113202827
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No
Location: Toronto

Rls encoder and vfd calibration

Post by nicolasjolliet »

Hi folks, after reading this thread on the forum : viewtopic.php?f=60&t=4043&p=33003&hilit ... all#p33003
I decided to go this way with my Taig mill and lathe with glockcnc spindle and motors.

I ordered and installed the encoder and ring from RLS (encoder RLC21ca06b and ring MR047B).
IMG_3421.jpg

report_4C3FD31F8733-1212192740_2020-10-16_08-00-33.zip[/attachment]

I'm having problems getting the motor to match the commanded rpm speed. I've read every documentation and forum posts I could find and can't get it to work properly, So I thought you guys could help.

Here is my problem:

By playing with the Max spindle speed in Acorn against the maximum rpm in the motor driver i can tune it to match any speed, let's say 5k rpm (50%).
When doing so, anything above goes too fast, anything below goes too slow. Acorn Voltages outputs have been tested and are correct.
IMG_3422.jpg
To fix this I would have to find the "bias" or "gain" on the vfd as suggested in the Acorn documentation:
Screen Shot 2020-10-15 at 16.29.50.png
My vfd and motor are from Glockcnc.com, it seems to be a generic Chinese vfd with a very badly tanslated manual and I can't find a parameter that would help my problem.
Screen Shot 2020-10-16 at 11.37.44.png
the Analog input dead band P1。12 doesn't help me to bias. I called Glockcnc but he couldn't help me, he has to contact the factory in china and that'll take a while.

the minimum spindle speed in Acorn didn't help me either.

I was wondering if there was parameters somewhere in Acorn that I could play with, that would help me skew things the right way?
Any other ideas?

Also, one last question, is it normal for the encoder reading to fluctuate constantly in Acorn? for example it goes from 5001 to 5003 to 5005 rpm several times per second.

Thanks folks.
tblough
Posts: 3072
Joined: Tue Mar 22, 2016 10:03 am
Acorn CNC Controller: Yes
Allin1DC CNC Controller: Yes
Oak CNC controller: Yes
CNC Control System Serial Number: 100505
100327
102696
103432
7804732B977B-0624192192
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No
Location: Boston, MA
Contact:

Re: Rls encoder and vfd calibration

Post by tblough »

AFAIK, there are no parameters in CNC12 to modify the DAC output, you would have to modify the DAC section of the PLC if you wanted to add slope control from the Acorn side. Not a very capable VFD if there are only 14 parameter to control it. Can you post the complete VFD manual?

It is not uncommon for the motor speed to vary a percent or two when controlled with a VFD.
Last edited by tblough on Fri Oct 16, 2020 12:03 pm, edited 1 time in total.
Cheers,

Tom
Confidence is the feeling you have before you fully understand the situation.
I have CDO. It's like OCD, but the letters are where they should be.
nicolasjolliet
Posts: 56
Joined: Wed Mar 18, 2020 4:15 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: 0113202827
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No
Location: Toronto

Re: Rls encoder and vfd calibration

Post by nicolasjolliet »

yah, cheap vfd it seems.
here is the "manual"
https://s3.amazonaws.com/precisionmachi ... Driver.pdf
martyscncgarage
Posts: 9912
Joined: Tue Mar 28, 2017 12:01 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: Yes
Oak CNC controller: No
CNC Control System Serial Number: none
DC3IOB: No
CNC12: Yes
CNC11: Yes
CPU10 or CPU7: Yes
Location: Mesa, AZ

Re: Rls encoder and vfd calibration

Post by martyscncgarage »

nicolasjolliet wrote: Fri Oct 16, 2020 12:03 pm yah, cheap vfd it seems.
here is the "manual"
https://s3.amazonaws.com/precisionmachi ... Driver.pdf
That is not a VFD. That is a brushless servo drive....
It also looks from the wiring diagram that it uses 0 to +5VDC for control, not 0 to +10VDC
Speed Control.JPG


There will be tuning involved since you are trying to run a spindle with a servo drive......
I assume you cant get help from the manufacturer?
Reminder, for support please follow this post: viewtopic.php?f=20&t=383
We can't "SEE" what you see...
Mesa, AZ
nicolasjolliet
Posts: 56
Joined: Wed Mar 18, 2020 4:15 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: 0113202827
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No
Location: Toronto

Re: Rls encoder and vfd calibration

Post by nicolasjolliet »

No help from the manufacturer. I called James at Glockcnc and he couldn't help me, he has to call the factory and that will take some time. James said he didn't have this problem before and that it works with acorn.

Also I saw the 0 to 10v here in the manual, it's weird because if you use a pot you use 5v, even though the sv takes 0 to 10v.

"Functions1. Speed adjustment methodThis driverprovide below threeadjust methods for the user to choose:Analog voltage adjustment speed: the terminalsof external potentiometer connect tothe +5v terminalin signal control and COM, connect the regulator terminal to SV, not only make it possible to adjust speed by external potentiometer(10K~100K), but also can achieve speed adjust through other control unit(Such as PLC,Microcontroller, etc) input analog voltage to SV. The acceptance of SV is DC 0V~+10V, and the corresponding motor rotate speed is 0 to rated speed.

You also can use external digital signal to adjust speed: apply PWM with 5V amplitude and 1KHz~2KHzFrequency between SV and GND to adjust the speed. The motor rotate speed will adjust by the duty radioliner adjustment."

maybe I can make some sort of a voltage divider to half the acorn output?
martyscncgarage
Posts: 9912
Joined: Tue Mar 28, 2017 12:01 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: Yes
Oak CNC controller: No
CNC Control System Serial Number: none
DC3IOB: No
CNC12: Yes
CNC11: Yes
CPU10 or CPU7: Yes
Location: Mesa, AZ

Re: Rls encoder and vfd calibration

Post by martyscncgarage »

Check the KBSI240D manual, it may allow the output to be 5 OR 10vdc
Reminder, for support please follow this post: viewtopic.php?f=20&t=383
We can't "SEE" what you see...
Mesa, AZ
nicolasjolliet
Posts: 56
Joined: Wed Mar 18, 2020 4:15 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: 0113202827
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No
Location: Toronto

Re: Rls encoder and vfd calibration

Post by nicolasjolliet »

Thanks, I’ll check it out.
But I think my driver takes 10v as I would get the maximum speed when sending 10v. I’ll try to send 0-5v with an external dc power supply and see.
nicolasjolliet
Posts: 56
Joined: Wed Mar 18, 2020 4:15 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: 0113202827
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No
Location: Toronto

Re: Rls encoder and vfd calibration

Post by nicolasjolliet »

I got an email from Glockcnc, he says the manual takes 0-5v, but this one was made special for glockcnc, and it takes 0-10v.
onward....
I really don't know what to do at this point.
martyscncgarage
Posts: 9912
Joined: Tue Mar 28, 2017 12:01 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: Yes
Oak CNC controller: No
CNC Control System Serial Number: none
DC3IOB: No
CNC12: Yes
CNC11: Yes
CPU10 or CPU7: Yes
Location: Mesa, AZ

Re: Rls encoder and vfd calibration

Post by martyscncgarage »

Sorry, getting you confused with another user.
There must be a setting in the drive to allow TOP speed to be set. That TOP speed I would expect to be met when 10VDC is applied to the drive input.
Then the issue is what the actual spindle speed is. Then adjusting that top speed value in the drive until the expected spindle speed is met.
Its all I can think of...
Reminder, for support please follow this post: viewtopic.php?f=20&t=383
We can't "SEE" what you see...
Mesa, AZ
nicolasjolliet
Posts: 56
Joined: Wed Mar 18, 2020 4:15 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: 0113202827
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No
Location: Toronto

Re: Rls encoder and vfd calibration

Post by nicolasjolliet »

Ok, thanks Marty.
the top speed i can set, it's the bottom speed i need to set in order to have a linear line at 45deg.
so if I set 5k to 5k, so 1k is 1k, 8k is 8k as well.
IMG_3422.jpg
Post Reply