Uncoordinated Movements with Stepper Motor

Drive a 4-wire bipolar stepper motor or a pair of DC motors from your Arduino. [Product page]
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xtoph
Posts: 2
Joined: Mon Jun 13, 2016 10:18 am

Uncoordinated Movements with Stepper Motor

Post by xtoph » Mon Jun 13, 2016 10:51 am

Hi Guys,
Getting a bit frustrated with this stepper motor setup that I just can't seem to get working. I'm an absolute beginner when it comes to electronics (and this forum) so I would be incredibly appreciative of any easy to understand advice anyone could offer.

Components:
- “Eleven” Board (http://www.freetronics.com.au/collectio ... 16E2uZ96EK)
- H-Bridge Shield (http://www.freetronics.com.au/collectio ... 16FGeZ96EK)
- Stepper Motor (400 steps/rev) (http://www.australianrobotics.com.au/pr ... -steps-rev)

Assembly:
I bought the above components at the advice of an engineering friend and then followed all the instructions on the freetronics website (http://www.freetronics.com.au/pages/hbr ... 14psFe0Y_5), hooking up the Black/Green and Red/Blue coils onto the seperate outputs on the bridge (http://www.australianrobotics.com.au/si ... 0.9deg.pdf). I also added a 1A power supply which I can vary at steps from 3V - 12V, none of which affect the problem below.
12922061_10209296327428047_1716834731_o.jpg

The Problem:

I uploaded and ran the code specified on the above mentioned website. The result was disappointing, instead of the precise alternating clockwise/counterclockwise revolutions specified in the code, the steppers’ movements were totally erratic. The motor buzzes, vibrates and makes a painful noise as if it were making an effort, but only manages to move a few degrees in random back and forth patterns. These efforts are interspaced by the delays in movement which the code specifies.

Video: https://sendvid.com/xrxpmgkf

In terms of the code, I tried changing around the rpm, the steps per revolution and delays between movements. This changes the erratic movements somewhat but nothing has made it run anything like it’s supposed to. I’ve also changed the amp switches on the H-Bridge between the 0.6, 1.2 and 2.0 Amp settings.

angusgr
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Re: Uncoordinated Movements with Stepper Motor

Post by angusgr » Mon Jun 20, 2016 7:55 am

Hi xtoph,

Sorry for the frustrating experience wiring up the motor. It sounds like you're very close to having it working, though.

Usually movements like what you're describing are caused by wiring problems with the coils. The links you posed to the australianrobotics site for the motor aren't working for me, do you have any other links I can follow to get information on the exact stepper motor you have?

Angus

xtoph
Posts: 2
Joined: Mon Jun 13, 2016 10:18 am

Re: Uncoordinated Movements with Stepper Motor

Post by xtoph » Thu Jun 30, 2016 3:06 pm

Hey Angus,

Thanks a lot for your reply and bringing my attention to the link which no longer appears to be active. I have attached a screenshot of what the linked pdf was supposed to show.
Stepper Specs.png
Would be very excited to get this working.

xtoph

angusgr
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Joined: Tue Apr 09, 2013 11:19 pm
Location: Melbourne, Australia
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Re: Uncoordinated Movements with Stepper Motor

Post by angusgr » Mon Jul 04, 2016 5:35 am

Hi xtoph,

Thanks for posting the datasheet. I can't see any problems with the wiring, although the video looks to me a lot like it could be a coil wiring problem.

If you use a multimeter in Resistance to measure each coil (blue to red, then green to black), do you see resistance in each pair? What happens if you swap the polarity on one of the coils (ie swap the red and blue wires)?

Angus

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