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Compatible Stepper Motors for RPi Motor HAT Mini
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Compatible Stepper Motors for RPi Motor HAT Mini

by Phuntimes on Wed Apr 24, 2019 8:35 pm

I'm working on a project that is a modification of FluxGarage's turntable. In addition to replacing:

  • Arduino -> RPi
  • EasyDriver -> Adafruit DC & Stepper Motor HAT for Raspberry Pi - Mini Kit
  • taller standoffs

I'm interested in using a planetary gearbox to increase the step precision. I found some reasonably priced combos (stepper + gearbox ) from StepperOnline.

The only motors that appear to be 12V and 0.4 A/phase are the following:


I'm assuming these are the only ones compatible with the HAT as the others are 2.7 V and 1.68 A/phase?

I'm open to suggestions if anyone is aware of similar products.

Phuntimes
 
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Joined: Wed Apr 24, 2019 5:28 pm

Re: Compatible Stepper Motors for RPi Motor HAT Mini

by adafruit_support_bill on Thu Apr 25, 2019 5:39 am

The two linked are compatible motors.

The critical parameter for HAT compatibility is the phase resistance. The drivers on the HAT do not have current limiting, so you need to use motors with a phase resistance high enough to self-limit the current to a safe level. The motors linked both have a phase resistance of 30 ohms, so when powered with 12v they will draw a maximum of 0.4A/phase.

https://learn.adafruit.com/all-about-st ... he-stepper

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Re: Compatible Stepper Motors for RPi Motor HAT Mini

by Phuntimes on Thu Apr 25, 2019 6:36 pm

Thanks for the confirmation. I see that MotorKit is capable of micro-stepping, but I don't see anything about it on the TB6612FNG datasheet. If its possible, how (hardware) is this accomplished and what's the range of micro-steps I can use?

Phuntimes
 
Posts: 2
Joined: Wed Apr 24, 2019 5:28 pm

Re: Compatible Stepper Motors for RPi Motor HAT Mini

by adafruit_support_bill on Thu Apr 25, 2019 6:46 pm

On the shield, microstepping is accomplished using the PWM capabilities of the PCA9685 chip on the board. The default is 16:1 microstepping. The library can be tweaked for 8:1.

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Please be positive and constructive with your questions and comments.