Have SB PRT Alpha ('04 model) - want to drive with Mach3 and parallel cable

[Gerald D]

Hi Mike and Dirk :)

Have been asked how to use Mach3 and parallel port to drive a ShopBot PRT Alpha (circa 2004) control box. My first reaction was to say, pull out the control board and replace it with a PMDX-122. (This is for a bloke who is building a MechMate as well and will be using PMDX-122 in a whole new control box).

Is that feasible; to drive the Alpha drives from the PMDX-122?

Thanks

Gerald

[Richards]

Gerald,
The Oriental Motor Alpha driver can accept step and direction signals, so the PMDX-122 board should work; however, the Alpha driver requires a 34-pin cable connection, requiring that you use a custom connection cable. (The function switches must be configured properly to use Step/Direction. As with most Orientral Motor stepper drivers, the Alpha drivers have a switch setting that allows CW/CCW pulses instead of Step/Direction.) The other problem with using an Alpha drive/motor is that the resolution is only 1/4 or 1/2 as good as a Gecko driven motor. The alpha stepper driver has provisions for 500 or 1,000 steps per shaft rotation with the addtional possibility of using the 10X multiplier switch settings for 5,000 pulses or 10,000 pulses per shaft rotation. However, at the 10X setting, the Mach 3 pulse generator could not furnish pulses fast enough to get desirable speed from the alpha driver/motor.

[Gerald D]

Thanks Mike, you made me remember we covered this ground recently - over here (http://www.mechmate.com/forums/showthread.php?p=5205). Sorry that I forgot.

[Richards]

Gerald, I forgot also. Thank goodness the answer was similar to the other one.:)