Bipolar motor voltage

[wildbill]

I recently got some bipolars from a forum member, they are 23HS8404's by Motion King, in the spec sheet on their website, there is no listing for the voltage of these motors, can anyone help with this ?

Wildbill

[irving2008]

thats because the voltage of the motor is fairly irrelevant for a bipolar motor. Its the current that matters and assuming you have a constant current driver (e.g. either a chopper or PWM) that is the key value. The other key parameter is inductance of the windings as this tells you how the motor torque will roll off at speed and therefore the ideal driver voltage, which is 32 x sqrt(inductance in mH). so a 3mH motor ideally would like a 32 * 1.732 = 55v driver. Of course a lower voltage will work but wont get the same torque at the higher speeds.

If you want to know more just ask...

[Swarfing]

Bill
First hit on google says

23HS8404 Double stack, 76mm, 6mm, 1.8, 40vdc/4.2amp/2 phase, 180N.cm

[Swarfing]

Irv you clicked [enter] at the same time

[irving2008]

Thats the breakdown voltage of the windings, not the operating voltage. A more useful spec is http://www.alibaba.com/product-gs/28...ze_57mm_1.html which shows these are 4.2A 0.6ohm motors (nominal coil volts 2.52v) and 1.8mH so ideal driver is 42v, they should work good on a 36v driver.

[wildbill]

Thanks for that, the motors are double stack, 76mm long and are (i think) based on nema23's the motion king website states that the current rating is 4.2 amps, i dont know if thats per winding (per phase ?). Can you recommend suitable drivers for these ? I have already started building the table and gantry with bearings made from alli angle and skatebord bearings, i would like to get these motors turning and download some software, just to get thing moving along (no pun intended). lots to think about. Thanks for your help.

Wildbill.

[wildbill]

While im on, derlin nuts ? ballscrews ? backlash? , it would be very helpful if there were a place on the forum for a glossary of terms and explanations of what these and other related thing were, to help newbs like myself. I know there is loads of info here, but that would be great if it was all in one place.

[irving2008]

Thanks for that, the motors are double stack, 76mm long and are (i think) based on nema23's the motion king website states that the current rating is 4.2 amps, i dont know if thats per winding (per phase ?). Can you recommend suitable drivers for these ? I have already started building the table and gantry with bearings made from alli angle and skatebord bearings, i would like to get these motors turning and download some software, just to get thing moving along (no pun intended). lots to think about. Thanks for your help.

Wildbill.

These are bipolar 4 wire motors. the rating is per phase. Ideally you'd want drivers capable of 4.2A/phase, 36V to drive these, such as Zapp's PM542 . For three axis you'd need a 10A power supply, such as this one on ebay.

[wildbill]

Thanks for that to all that responded. So, would i be correct to think that the backlash is the slack between the nut and the threaded bar ?. I think i got an idea (to quote Michael Caine) on how to work around this problem with low cost studding !!! i'll work on it and update asap. Thanks again to all, this is just the info a newb requires.

Wildbill.

[Swarfing]

the is what was on http://www.rhonmac-cnc.co.uk/electronic_hardware.htm. shame they never explain?