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If no information is available for current limit, encoder cpr, and the number of poles.

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Forum 1
(@hillhenry1)
Posts: 4
Active Member
Topic starter
 

Hello, I bought a motor from: https://www.ato.com/50-w-dc-gear-motor.

On the website, I wasn't able to find some information, including stall current, encoder cpr, and the number of poles. I requested these information but it doesn't seem like it was available.

 

So, I entered in arbitrary values for these on the Motion Terminal. 15A for current limit, 1000 for encoder lines, and 8 for the poles.

I tried hall sensors calibration with 6 different combinations of wiring, but perhaps due to this, hall sensors calibration failed with a timeout. (Motor did turn and position graph did move.)

 

I would appreciate any advice going forward, including buying a different motor or methods for testing/dealing with these unknown parameters.

 
Posted : 04/11/2022 6:10 am
SOLO Team
(@milad)
Posts: 445
Illustrious Member Admin
 

Hello @hillhenry1,

Posted by: @hillhenry1

I tried hall sensors calibration with 6 different combinations of wiring, but perhaps due to this, hall sensors calibration failed with a timeout. (Motor did turn and position graph did move.)

As your motor comes with "HALL sensors", the number of "Encoder Line" won't have any use, as that number is used once you are using an "Incremental Encoder with Index pulse" for the sensor, so basically do you confirm that you are following this tutorial and video within it to calibrate your Hall sensors and the Motor?

Posted by: @hillhenry1

I would appreciate any advice going forward, including buying a different motor or methods for testing/dealing with these unknown parameters.

Since you are in Hall mode, the only parameter that is critical for the Calibration would be the number of Poles, so basically the number of Poles on a BLDC motor is the number of Magnets mounted on the rotor of the Motor, this value will be used during the calibration and if the number is not correct the found calibration values won't be correct, resulting SOLO identifying a wrong Torque vector for your sensor.

So if the manufacturer of the motor can't tell you about the number of Poles, the only way would be to open up the motor and count the number of magnets, from the look of your motor and my past experiences, it looks to have 4, 6 or 8 poles, but the safest way would be to open it up and count the magnets.

It seems your motor has a rated current of 5.2A based on the table on the given page, so you might want to keep the current limit at a max of 6A, to begin with.

Let me know if you have any other questions.

Milad

 

 

If you found the answers helpful and you could solve your problems, please kindly verify here to help others in the future.

 
Posted : 04/11/2022 8:45 am
hillhenry1 reacted
Forum 1
(@hillhenry1)
Posts: 4
Active Member
Topic starter
 

@milad 

I see. I was watching the other video with encoder calibration, not the hall sensor one. Thanks for your answer on those 3 unknown parameters.

 

But now I think my problem is different than having those 3 arbitrary parameters.

- Hall sensors calibration is still failing with timeout, after trying 6A for current limit and trying different values for poles.

combination6

And I'm also getting this error:

image
 
Posted : 05/11/2022 4:05 am
SOLO Team
(@milad)
Posts: 445
Illustrious Member Admin
 

@hillhenry1 ,

1) So before running the Hall sensor calibration, once you turn the motor manually, do you confirm that you see the Angle shapes as suggested in this article?

Forum 5

2) Can you send me a full screen-shot from your Motion terminal parameters ( visible in Express section )

3) may I know your Firmware version?

 

Regards
Milad

 

 

If you found the answers helpful and you could solve your problems, please kindly verify here to help others in the future.

 
Posted : 07/11/2022 8:42 am
Forum 1
(@hillhenry1)
Posts: 4
Active Member
Topic starter
 

1. It does. But it looks like 4th image. Square.

3. 0000B000D.

image1
image2
image3
image4
image5

Best Regards.

 
Posted : 07/11/2022 9:24 am
SOLO Team
(@milad)
Posts: 445
Illustrious Member Admin
 

@hillhenry1 :

Posted by: @hillhenry1

1. It does. But it looks like 4th image. Square.

Actually this is not a good shape, the Signal of the Angle should be like a saw-tooth signal starting from a minimum value and increasing smoothly to a max value or vice versa, so it seems your HALL sensors are not well connected, could you test :

  1. The Hall sensors are properly wired up and powered?
  2. if you see the same behavior on a different configuration of the Hall sensors connected to SOLO ( you can swap the CHA and CHC and see if the plots remain the same)?

 

I will be waiting for your updates.

 

Milad

 

If you found the answers helpful and you could solve your problems, please kindly verify here to help others in the future.

 
Posted : 07/11/2022 9:49 am
Forum 1
(@hillhenry1)
Posts: 4
Active Member
Topic starter
 

@milad 

Thanks for your help. After I rewired the motor encoder cables, everything worked well.

I'm sorry about that. Have nice Monday.

 
Posted : 07/11/2022 10:13 am
SOLO Team
(@milad)
Posts: 445
Illustrious Member Admin
 

@hillhenry1 , that's great, let me know if you had any other questions along the path.

 

Milad

 

If you found the answers helpful and you could solve your problems, please kindly verify here to help others in the future.

 
Posted : 07/11/2022 10:18 am
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