Re: [CAD_CAM_EDM_DRO] Need to convert small stepper to larger motor

At 10:02 AM 5/24/2007, you wrote:

>Any suggestions on how to drive a bigger motor from the existing 4
>wires? Power an external H-bridge? Convert to an electronic step
>signal that I could use, after digital gearing, to drive a gecko?
>Thought about mounting an encoder on existing motor to generate step
>signals for a gecko/servo with identical encoder but I don't think
>that would work. I don't know if encoder a/b pulses equate directly to
>gecko step pulses. Direction is not an issue.

Got a scope? Look at each of the four wires as the motor is running
with a 10x probe (you can see over 100 Volt spikes which can kill
cheap scopes.)

Do all four switch? If not, you may have a three phase motor, wye
(Y) connected. If they all switch and the voltages look reasonable,
use a one-shot on each and "or" them and you have your steps. Need
schematics? Then ANY cheap driver board becomes reasonable, just tie
the direction line high OR low and adjust the wiring to the new motor.


David G. LeVine
Nashua, NH 03060