I bought a 57oz-in (1Nm) NEMA 17 12v 1.3A stepper to use with the AdaFruit v2 motor shield. But when it is connected, and I run my code, nothing happens. Below is the coil wiring privided from the manufacturer.
Bipolar
Coil 1:
Black A
Green A-
Coil 2:
Red B
Blue B-
Connected to M1-M2 in order, skipping the middle (ground).
My code works perfect with the motor I bought from Adafruit. I assume that this may be a motor wiring issue but I'm not sure. Could it be that the 1.3A motor just too much for this shield?
Thanks.
Problems with Stepper motor connected to v2.3 shield
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Please be positive and constructive with your questions and comments.
- shakezoola
- Posts: 19
- Joined: Wed May 13, 2015 4:51 pm
- adafruit_support_mike
- Posts: 67485
- Joined: Thu Feb 11, 2010 2:51 pm
Re: Problems with Stepper motor connected to v2.3 shield
Motors don't always meet the written wiring spec, but never lie to a ohmmeter.
Check the resistance between the terminals. Bipolar motors are easy because you get all-or-nothing results. If the resistance between two wires is a few ohms, they belong to the same coil. If the resistance is infinite, they belong to different coils.
Check the resistance between the terminals. Bipolar motors are easy because you get all-or-nothing results. If the resistance between two wires is a few ohms, they belong to the same coil. If the resistance is infinite, they belong to different coils.
- shakezoola
- Posts: 19
- Joined: Wed May 13, 2015 4:51 pm
Re: Problems with Stepper motor connected to v2.3 shield
I measured the resistance of my motor, and it confirmed that the coil pairs are black/green and red/blue.
------------Black--------Green--------Red--------Blue
Black--------------------2.7Ω--------0.289Ω-----0.292Ω
Green------2.7Ω---------------------0.298Ω-----0.298Ω
Red----- 0.289Ω------0.298Ω-----------------------2.8Ω
Blue-----0.292Ω------0.298Ω---------2.8Ω-------------
The motor still behaved erratically.
I also measured the resistance of my working motor and found that the resistance of each pair was much higher (~34Ω) than my new motor. Is it possible that it could be defective? Or is it still possible that the 1.3A of this motor is causing the problem?
------------Black--------Green--------Red--------Blue
Black--------------------2.7Ω--------0.289Ω-----0.292Ω
Green------2.7Ω---------------------0.298Ω-----0.298Ω
Red----- 0.289Ω------0.298Ω-----------------------2.8Ω
Blue-----0.292Ω------0.298Ω---------2.8Ω-------------
The motor still behaved erratically.
I also measured the resistance of my working motor and found that the resistance of each pair was much higher (~34Ω) than my new motor. Is it possible that it could be defective? Or is it still possible that the 1.3A of this motor is causing the problem?
- Franklin97355
- Posts: 23940
- Joined: Mon Apr 21, 2008 2:33 pm
Re: Problems with Stepper motor connected to v2.3 shield
The motor is probably not defective just not designed for the type of controller the shield is. There are other motor drivers that could drive this motor.
- shakezoola
- Posts: 19
- Joined: Wed May 13, 2015 4:51 pm
Re: Problems with Stepper motor connected to v2.3 shield
I can test the motor with another driver to make sure it is not defective.
To keep things simple consistent, I was hoping to use this motor shield with a motor that has more running torque than the nema 17 motor sold on the adafruit Web site.
Can you recommend a high torque stepper that works with this shield?
Thanks for your quick responses!
To keep things simple consistent, I was hoping to use this motor shield with a motor that has more running torque than the nema 17 motor sold on the adafruit Web site.
Can you recommend a high torque stepper that works with this shield?
Thanks for your quick responses!
- adafruit_support_bill
- Posts: 88154
- Joined: Sat Feb 07, 2009 10:11 am
Re: Problems with Stepper motor connected to v2.3 shield
Based on the very low phase resistance, I believe that motor was designed for use with a current limiting driver.
https://learn.adafruit.com/all-about-st ... he-stepper
https://learn.adafruit.com/all-about-st ... he-stepper
- shakezoola
- Posts: 19
- Joined: Wed May 13, 2015 4:51 pm
Re: Problems with Stepper motor connected to v2.3 shield
After reading the article in the link provided (not sure how I missed that one) it seems that this is not a 12V as indicated when I purchased it on-line.
Please correct me if I am wrong, but based on the current rating and resistance of the motor, it looks to be 3.5V. 1.3A x 2.7Ω = 3.51V
The motor I bought from Adafruit works fine because it is a 12V motor: .350A x 34Ω = 11.9V
Which would explain why this motor does not function correctly since the motor shield is designed for 5V-12V.
Am I on the right track?
Please correct me if I am wrong, but based on the current rating and resistance of the motor, it looks to be 3.5V. 1.3A x 2.7Ω = 3.51V
The motor I bought from Adafruit works fine because it is a 12V motor: .350A x 34Ω = 11.9V
Which would explain why this motor does not function correctly since the motor shield is designed for 5V-12V.
Am I on the right track?
- adafruit_support_bill
- Posts: 88154
- Joined: Sat Feb 07, 2009 10:11 am
Re: Problems with Stepper motor connected to v2.3 shield
Yes, advertised specifications are often incomplete. Voltage specs in particular can be misleading.... it seems that this is not a 12V as indicated when I purchased it on-line.
I don't think that the vendors are being dishonest. I think some just don't understand what all the numbers mean. Motors designed for operation with current limiting drivers will often list a suggested supply current - with the assumption that the driver will be configured to limit the current to the max current rating.
When looking at motor specs for use with a non-current limiting driver such as the shield, the important numbers are the phase resistance and the current rating. You can figure out the voltage from there.
Yes, it looks that way!Am I on the right track?
- shakezoola
- Posts: 19
- Joined: Wed May 13, 2015 4:51 pm
Re: Problems with Stepper motor connected to v2.3 shield
Awesome! Thanks to all for your help.
Please be positive and constructive with your questions and comments.