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Stepper Motor Project
Moderators: adafruit_support_bill, adafruit

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Stepper Motor Project

by teddylambert on Tue Jul 30, 2019 10:49 am

Hi everyone,

I am making a project that has two stepper motors controlled by the Adafruit v2 motorshield on top of an Arduino Mega. I am using these steppers, which are rated at 3.96V and 0.9A. I need to control both steppers at once, and ideally would only like to use one power cord to do so. I understand that since I will have both phases active on the motors, I need a power supply with at least 2*(0.9+0.9)= 3.6A. However, I also know that Arduino recommends that its barrel jack be fed with 7-12V and that anything lower will be unstable. My question is that if I have a 12V 5A power supply already in my possession, does the Arduino and/or motor shield have any voltage/current regulation so that this supply would work with the project? If not, is it even possible to run the project through a single cord as I couldn't feed 5V through the Arduino power jack and the USB port cannot draw enough current? Otherwise I'm assuming my best option is to get a 5V 4A power supply to run the motors through the 5-12V terminal block on the shield and just power the arduino seperately.

Thanks!

teddylambert
 
Posts: 3
Joined: Mon Jul 01, 2019 6:17 pm

Re: Stepper Motor Project

by adafruit_support_bill on Tue Jul 30, 2019 11:15 am

I am using these steppers, which are rated at 3.96V and 0.9A.

Unfortunately, the motor specifications posted there are incomplete. The one parameter missing from the spec -phase resistance- is the one required to determine compatibility with the shield. https://learn.adafruit.com/all-about-st ... he-stepper

If you take the voltage spec at face value, and back-calculate the phase resistance, you end up with 4.4 ohms. Which tells me that you can't take the voltage spec at face value.

The motor was most likely designed to run with a higher voltage supply and a current limiting driver. Unfortunately, the motor shield does not have current limiting. For that you would need something like the DRV8833.
https://www.adafruit.com/product/3297

adafruit_support_bill
 
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Re: Stepper Motor Project

by teddylambert on Tue Jul 30, 2019 11:49 am

Ok, thank you! I am hoping to keep the set up mostly the same so it seems like new steppers are necessary, it looks like these would be a much better fit correct?

Specs:
Manufacturer Part Number: 17HS15-0404S
* Motor Type: Bipolar Stepper
* Step Angle: 1.8 deg.
* Holding Torque: 40Ncm(56.6oz.in)
* Rated Current/phase: 0.4A
* Phase Resistance: 30.0ohms
* Inductance: 58mH+/-20%(1KHz)

teddylambert
 
Posts: 3
Joined: Mon Jul 01, 2019 6:17 pm

Re: Stepper Motor Project

by adafruit_support_bill on Tue Jul 30, 2019 12:39 pm

Yes. Those motors should work fine with the shield.

adafruit_support_bill
 
Posts: 74337
Joined: Sat Feb 07, 2009 10:11 am

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