View Full Version : Reversing alpha moters

Wes Day (Unregistered Guest)
09-12-2004, 01:21 AM
On the old PRS's you switched the red and green wires on the motor to reverse the direction. Is the same true for the alpha motors? The way my shop is setup I need to "swap" the 0,0 to the opposite corner and run the other direction.


09-12-2004, 03:04 PM
Hi Wes
I reversed my motors on X and Y to change "home" to opposite corner on my PRT (was about 2 yrs ago) If memory serves me , I changed the GREEN & BLACK wires to reverse motor direction..

Brady Watson
09-12-2004, 03:09 PM
Why don't you just spin the entire gantry 180?

...or is this not a permanent thing?


09-12-2004, 08:25 PM

I'm not at the shop, but after a quick glance at the Oriental Motor web site, it looks like it would be simple to reverse the direction of the Alpha motors by changing an input signal or signals to the controller rather than changing the wires going from the controller to the motor.

The Alpha motors, like the Vexta series and the CSK series motors that I use from Oriental Motors, both have a clockwise/counterclockwise switch or wire connection on the controller. A quick call to support in the morning should get you going.

Brady Watson
09-12-2004, 10:43 PM
That makes sense to change the wires on the Alpha controller...I am pretty sure that the Alphas are AC, so merely swapping wires after the controller might not do anything.


09-13-2004, 10:31 AM
You can download the controller manual from Oriental's website. On page 1, the connections to the motor are defined. (Inputs 9-12 on the 34 pin connector are inputs for step and direction.) On page 3, the step and direction signals are explained.

In any case, unless you are totally familiar with Oriental Motor and their excellent steppers, a quick call to Shopbot support would clear things up.

Technically, voltage to the controller on the alpha motors is AC. Voltage to the motor itself is DC. The master controller sends a series of pulses, one pulse for each rotational step of the motor. In the one step configuration, one input line is held high for CW rotations and low for CWW rotation, while another input is pulsed at the rotational pulse rate desired. In the two step configuration, the CW input is pulsed to rotate the shaft CW and the CWW input is pulsed to rotate the shaft CWW.