I just bought these two pac-sci motors:
They both are identicle, just diff names. Here are the specs when wired:
P22NXXA-LXX-XX-00 • 197 Bipolar Paralell (1.39) 6.5 AMPS
P22NXXA-LXX-XX-00 • 197 Bipolar Series(1.39) 3.3 AMPS
P22NXXA-LXX-XX-00 • 139 Unipolar (0.98) 4.6 AMPS
Is there any drives that can be had for under $100? This includes two drives. I don't mind building one. I just realized that these wern't 3.3amps bipolar parallell, and I thought before buying them, that if wired in unipolar would be somewhere around 2.31 amps unipolar. Well, I read all that wrong (It was bipolar series not parallel), and now I bought them off ebay. I originally was gonna power these off of a hobbycnc unipolar, but now it looks like I need another drive. Any ideas? Thanks - Zack
Last edited by radicooldude; 12-21-2005 at 11:05 AM.
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(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)
Which one can support nearly 6amps? THe only one I see can support 3a. BTW, are drivers rated in paralell, or series? - Zack
Drivers don't care about series or parallel, they only care how many amps and volts you use. You could run your motors bipolar series at 3 amps and still get 90% of the rated holding torque. Drawback of series connection is that maximum speed would be about half that of the parallel connection. The P22NXXA drives have rather low inductance, so the series connection may be fast enough for you.
The only cheap 6amp drives I know about are the unipolar series resistor type, which I would not recommend. http://electronickits.com/kit/complete/motor/ck1405.htm
They are cheap, but better to go with a more modern microstepping drive.
So, if I purchased a hobbycnc board, or even a xylotex, and they are rated to 3amps, would they still run it, or would these motors blow the board? What I mean is, will the board limit the power to 3amps, or does the motors controll how much current? I am not that worried about speed, as I only need about 100oz of torque, and 10ipm. These are 200oz steppers.
Yes, with chopper type drives, the current is set on the drives and you can run less than the rated current of the motors. Holding torque is directly proportional to current, if you run the motors at half the rated current, you will get half the rated torque. Reduced current does not affect high speed torque as much as it does holding torque. The HobbyCNC board being unipolar, would give you less than half of the rated bipolar torque when run at 3 amps.