My Stepper Motor Doesn't Work. (maybe I should use a different one)

My Rugged Stepper Motor Driver still works great but it appears that my new stepper motor does not work.

I bought a 57BYG210 as an upgrade to a fully working 57BYG084. I wanted to change from a .06 amp motor to a 2.0 amp motor. I chose this motor because it was in the same series and therefore should plug and play without reconfiguration. It is the same size and has the same wiring diagram.

When I plugged in the new motor, it simply chattered, not making complete rotations except through randomized movement. Seeing that, I unplugged the new motor and plugged old one back in and it ran normally. With that, I plugged the new one in again and got the same chattering.

At that point, I tried reversing the wiring combinations several different ways but got no improvement or even any change. The new motor begins to chatter as soon as the Rugged Motor Driver is activated through the software, not just when the motor should be rotating.

Is there something that I forgot to try?

The 5BYG210 motor has a winding resistance of 1.0 ohms (maximum current 2.0 amps), and is intended for chopper-style motor drivers that actively limit the winding current. I don’t think the Rugged Motor Driver can be used with it, as the motor will draw 1 ampere per volt of power supply (or 1 ampere per 2 volts if you use series-connected windings).

I am not aware of any hobby outlets that sell chopper drivers that handle 2 A/winding without additional cooling but if you can get away with a bit less torque (at 1.5 amps/winding) then this will work: http://www.pololu.com/product/2133 Otherwise you will need an industrial grade chopper driver.

Edit: an alternative is to use your existing driver but put a suitable resistor, for example 6 ohm, 50 watts, in series with each winding to limit the winding current. Its exact value depends on the voltage of the motor power supply and the voltage drop across the H-bridge. The resistor will get very hot if you drive the motor at its rated current.

2A is pushing it for any single-chip chopper driver. You will need proper heatsinking if you go that route (metal finned heatsink, fan blowing on it).

I chose this motor because it was in the same series and therefore should plug and play without reconfiguration.

Doesn't follow - the same series for a motor means the same mechanics, but winding characteristics are very different.

Low impedance windings have low inductance and lower backEMF, which allows much faster stepping when driven from a chopper drive from a high voltage supply, but cannot be driven from a constant voltage H-bridge without pathetic maximum step rates or massively overheating or wasting lots of power in series resistors.

Low impedance windings are for current control, not voltage control...

I have a finish robot designed and built. I have working code with acceleration and deceleration. I have the Rugged Motor Driver and a 30V 5 amp power supply. Obviously, I just don’t have a clue how to spec. an appropriate stepper motor.

I think that I have a little more power that I can take advantage of between the .06A motor that I already have and the approx. 2.6 amp max output of the driver board. I only run the motor for 10 second or less at a time and turn off the motor for more than a minute between runs.

Given all that, does anyone have a suggestion for a better motor to buy that would give me a little more torque? (Perhaps I should post this question in the Project Guidance section)

From a brief Google (it would have been helpful if you had provided links) the 57BYG084 seems to have a holding torque of 6kg-cm and the 57BYG210 has 5.8kg-cm. So you seem to be down-grading (slightly).

Note that higher voltages won't give more holding torque on the -210, it will only maintain the torque at higher speeds.

It looks like you could use the -084 as a bipolar stepper with a chopper driver like the Pololu A4988 (ignoring the centre taps to the coils). That would allow you to use higher voltages and the -084 would be well within the A4988's current capacity.

...R