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Can Motor Shield v2.3 run 1.4A stepper motors
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Can Motor Shield v2.3 run 1.4A stepper motors

by hyunterx on Thu Aug 15, 2019 11:46 am

Hi there,

As per topic above, i am using a NEMA17 stepper motor with 1.4A/phase rated current as shown in the spec sheet below
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Can the motor shield run 1,4A stepper motor? If its not possible is there any alternative?

I am using a portable DC output pack which could control both voltages and current
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Re: Can Motor Shield v2.3 run 1.4A stepper motors

by adafruit_support_bill on Thu Aug 15, 2019 12:14 pm

1.4A is a limit for what the motor windings can tolerate. The actual current draw is a function of the supply voltage, the phase resistance and Ohm's Law:
https://learn.adafruit.com/all-about-st ... he-stepper

Base on the low phase resistance of that motor, it appears to have been designed for use with a current limiting stepper driver. It is not compatible with the motor shield.

A better match would be the DRV8833 which has current limiting up to 1.2A: https://www.adafruit.com/product/3297
www.pololu.com has a wider range of current limiting stepper drivers.

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Re: Can Motor Shield v2.3 run 1.4A stepper motors

by hyunterx on Thu Aug 15, 2019 12:28 pm

Hi there,

Many thanks for the reply.

Nonetheless, I have used this board before to control two of the same stepper motors and both of them runs fine. So I am puzzled to find out that both of them are not actually compatible.

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Re: Can Motor Shield v2.3 run 1.4A stepper motors

by hyunterx on Thu Aug 15, 2019 3:19 pm

adafruit_support_bill wrote:1.4A is a limit for what the motor windings can tolerate. The actual current draw is a function of the supply voltage, the phase resistance and Ohm's Law:
https://learn.adafruit.com/all-about-st ... he-stepper

Base on the low phase resistance of that motor, it appears to have been designed for use with a current limiting stepper driver. It is not compatible with the motor shield.

A better match would be the DRV8833 which has current limiting up to 1.2A: https://www.adafruit.com/product/3297
http://www.pololu.com has a wider range of current limiting stepper drivers.

Is it possible that I draw 1.2A from the controller to the stepper motor since you said that 1.4A is a limit that the winding's could tolerate since DRV8833 has a current limiting up to 1.2A?

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Re: Can Motor Shield v2.3 run 1.4A stepper motors

by adafruit_support_bill on Thu Aug 15, 2019 4:03 pm

I have used this board before to control two of the same stepper motors and both of them runs fine.

You may be able to get them to run for a while with a low supply voltage and/or a very high step-rate. But the shield itself can only handle 1.2A continuous, so you risk burning out the drivers on the shield.

Is it possible that I draw 1.2A from the controller to the stepper motor since you said that 1.4A is a limit that the winding's could tolerate since DRV8833 has a current limiting up to 1.2A?

Without any active current limiting, the current drawn by the motors is governed by the laws of physics as described in the link: https://learn.adafruit.com/all-about-st ... he-stepper
With active current limiting, the motor will follow the same laws of physics, but if i exceeds the set limit, the driver will start feeding power in short pulses to keep the average current draw below the set limit. The DRV8833 allows you to set a current limit up to 1.2A. That is a level that is safe for the motor. At 1.2A you will get about 85% of the rated motor torque.

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Re: Can Motor Shield v2.3 run 1.4A stepper motors

by hyunterx on Thu Aug 15, 2019 4:48 pm

adafruit_support_bill wrote:
I have used this board before to control two of the same stepper motors and both of them runs fine.

You may be able to get them to run for a while with a low supply voltage and/or a very high step-rate. But the shield itself can only handle 1.2A continuous, so you risk burning out the drivers on the shield.

Is it possible that I draw 1.2A from the controller to the stepper motor since you said that 1.4A is a limit that the winding's could tolerate since DRV8833 has a current limiting up to 1.2A?

Without any active current limiting, the current drawn by the motors is governed by the laws of physics as described in the link: https://learn.adafruit.com/all-about-st ... he-stepper
With active current limiting, the motor will follow the same laws of physics, but if i exceeds the set limit, the driver will start feeding power in short pulses to keep the average current draw below the set limit. The DRV8833 allows you to set a current limit up to 1.2A. That is a level that is safe for the motor. At 1.2A you will get about 85% of the rated motor torque.

Thanks very much now I kinda understand.
So as long as I maintain around 1 - 1.2A and calculate the needed low voltage supply using V=IR i should be ok in using the motor shield. Is it correct?
I actually found out that the shield is a constant voltage shield, so if my stepper motor need less than 5v to operate what would happen?

Also does the DRV8833 compatible with Arduino?

Thank you

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Re: Can Motor Shield v2.3 run 1.4A stepper motors

by adafruit_support_bill on Thu Aug 15, 2019 5:42 pm

So as long as I maintain around 1 - 1.2A and calculate the needed low voltage supply using V=IR i should be ok in using the motor shield. Is it correct?

That is 1.2A per-phase. Since most stepping motors energize two phases at a time, the total current draw will peak at twice the per-phase value. Not sure which of those motors you are using. But if your phase resistance is 3 ohms, you would need to keep the supply voltage to 1.2A * 3ohms = 3.6v. The motor will probably run, but you will have little torque.

Also does the DRV8833 compatible with Arduino?

Yes. If you follow the links in the product description, you will find a tutorial for hooking it up to an Aruduino.

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Re: Can Motor Shield v2.3 run 1.4A stepper motors

by hyunterx on Thu Aug 15, 2019 5:59 pm

adafruit_support_bill wrote:
So as long as I maintain around 1 - 1.2A and calculate the needed low voltage supply using V=IR i should be ok in using the motor shield. Is it correct?

That is 1.2A per-phase. Since most stepping motors energize two phases at a time, the total current draw will peak at twice the per-phase value. Not sure which of those motors you are using. But if your phase resistance is 3 ohms, you would need to keep the supply voltage to 1.2A * 3ohms = 3.6v. The motor will probably run, but you will have little torque.

Also does the DRV8833 compatible with Arduino?

Yes. If you follow the links in the product description, you will find a tutorial for hooking it up to an Aruduino.

I am using the one that has a rated current of 1.4A/phase. Therefore if my resistance is 1.9 Ohms/phase i will get around 2.7V of voltage is that correct?

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Re: Can Motor Shield v2.3 run 1.4A stepper motors

by adafruit_support_bill on Thu Aug 15, 2019 7:05 pm

1.4A/phase is the maximum for the motor. But 1.2A per phase is the maximum for the shield. So exceeding 1.2A risks damage to the shield.

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Re: Can Motor Shield v2.3 run 1.4A stepper motors

by hyunterx on Thu Aug 15, 2019 7:43 pm

adafruit_support_bill wrote:1.4A/phase is the maximum for the motor. But 1.2A per phase is the maximum for the shield. So exceeding 1.2A risks damage to the shield.

My bad, so its 1.2x1.9 = 2.2 is it correct?

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Re: Can Motor Shield v2.3 run 1.4A stepper motors

by adafruit_support_bill on Thu Aug 15, 2019 8:44 pm

Yes. At that voltage, I'd expect the torque to be quite weak.

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Re: Can Motor Shield v2.3 run 1.4A stepper motors

by hyunterx on Sun Aug 18, 2019 4:34 pm

HI there,

May I ask if there's any schematic in using 2 DRV8833 to control 2 stepper motors?

Thank you

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Re: Can Motor Shield v2.3 run 1.4A stepper motors

by adafruit_support_bill on Sun Aug 18, 2019 4:40 pm

We don't have any diagrams for that. But it is not difficult.

Connect GND, VMotor and Slp pins the same as for the first board.
Connect AIN1, AIN2, BIN1 and BIN2 to any 4 otherwise unused GPIO pins.

Specify those pins in the constructor when you declare the second instance of "Stepper".

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Re: Can Motor Shield v2.3 run 1.4A stepper motors

by hyunterx on Sun Aug 18, 2019 8:34 pm

adafruit_support_bill wrote:We don't have any diagrams for that. But it is not difficult.

Connect GND, VMotor and Slp pins the same as for the first board.
Connect AIN1, AIN2, BIN1 and BIN2 to any 4 otherwise unused GPIO pins.

Specify those pins in the constructor when you declare the second instance of "Stepper".


How bout power supply? I am using a portable DC generator

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Re: Can Motor Shield v2.3 run 1.4A stepper motors

by adafruit_support_bill on Mon Aug 19, 2019 5:52 am

As long as it is regulated and has sufficient power for both motors, it should not be a problem.
Connect GND and VMotor the same way as the first board.

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Please be positive and constructive with your questions and comments.