Testing stepper motors

I am currently in the middle of building my own design delta printer - closer to a Kossel than to a Rostock. I don't yet have the electronics - I'm not sure which direction I'm going - but I wanted to test the stepper motors I recently installed.

I have an adafruit motorshield for my arduino uno, so I connected the motor to it, connected a 12 volt power supply to the motor power supply, removed the jumper from the board, and proceeded to load and try the sample sketch that adafruit provides. I got SOME movement from the motors, but before anything substantial could happen, there was a big puff of smoke from the motor shield. I quickly disconnected everything.

I'm wondering 1) what I could have done wrong, and 2) did I damage my motor. According to the Lulzbot web site, the motor is rated at 2.8 volts. I'm not sure what the adafruit board puts out, but I was supplying 12 volts to it. I though I heard of people running their steppers at up to 24 volts, so I thought I'd be safe.

I guess it's possible that I hooked the motor up wrong. An on-line spec sheet indicated that green/black was one coil and red/blue was the other. I hooked them up in the order black, green, nc, blue, red as I was looking at the adafruit board.

Any assistance would be greatly appreciated.

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I guess it's possible that I hooked the motor up wrong.

This might result in not turning motors, but definitely not in smoking stepper drivers. Does this stepper driver feature current control? Is it for bipolar motors? Links to the actual items you use are always helpful.

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Thanks for responding.

Here is a link to the arduino shield: Adafruit Motor shield

and here is a link to the instructions I followed: Using the motor shield. Down at the bottom of the page are the instructions for a stepper, including the literal sketch I was testing with.

and finally - here is the motor:Lulzbot stepper

Any help would be appreciated.

jbernardis Wrote:
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> I'm wondering 1) what I could have done wrong, and
> 2) did I damage my motor. According to the
> Lulzbot web site, the motor is rated at 2.8 volts.
> I'm not sure what the adafruit board puts out,
> but I was supplying 12 volts to it. I though I
> heard of people running their steppers at up to 24
> volts, so I thought I'd be safe.

You can do that with latest Allegro chips etc because they are advanced chopper drivers with current control. The L293 are simple old school half-H type drivers, so you need to match supply voltage to motor voltage.

The motor is probably ok, the driver should have smoked before it could pass significant current through it.