Conversion Tables

Wiring Effect on Motor Electrical Ratings

Stepper motor manufacturers may rate their motors 3 different ways. 1) unipolar (or bipolar center tap to end), 2) Bipolar series and, 3) bipolar parallel. Most ratings for 6 lead motors are unipolar. Ratings for 4 lead motors are bipolar, while ratings for 8 lead motors can be any of the three. MicroKinetics motors are all rated for the unipolar method for consistency. You should use the chart below to adjust for the driver type and wiring you choose for your application. Because all MicroKinetics drivers are constant current, the main consideration is the current. Driving a 6 lead motor “end to end” will require only 70% of the rated current (when compared to the standard method of driving the motor “center tap to end”).

Rated Drive Scheme  
Desired Drive Scheme
   Rating  Unipolar multiplier  Bipolar series multiplier  Bipolar parellel multiplier
 Unipolar or Bipolar Center Tap to End
 volts
 Amps
 ohms
 mH
 holding torque
 1
 1
 1
 1
 1
 1.4
 0.7
 2
 4
 1.4
 0.7
 1.4
 0.5
 1
 1.4
 Bipolar Series
 volts
 Amps
 ohms
 mH
 holding torque
 0.7
 1.4
 0.5
 0.25
 0.7
 1
 1
 1
 1
 1
 5
 2
 0.25
 0.25
 1
 Bipolar parallel
 volts
 Amps
 ohms
 mH
 holding torque
 1.4
 0.7
 2
 1
 0.7
 2
 0.5
 4
 4
 1
 1
 1
 1
 1
 1

Torque

 
Multiply Number of
 dy-cm  g-cm  N-cm  kg-cm  N-m  oz-in  lb-in  lb-ft  
 1 980.7  105  9.807x105  107 7.062x104  1.130x106 1.356x107  dy-cm
 1.020x10-3  1 1.020x102  103 1.020x104  72.01   1.152x103  1.383x104  g-cm
 10-5 0.9807  1   9.807  100 0.7062  11.3  135.6   N-cm
 1.020x10-6  10-3  0.102 1  10.20   7.201x10-2  1.152  13.83  kg-cm
 10-7  9.807x10-5  10-2  9.807x10-2  1  7.062x10-3 0.113  1.356   N-m
 1.416x10-5 1.389x10-2  1.416   13.89  141.6 1   16  192 nbsp;oz-in
 8.850x10-7 8.681x10-4   8.850x10-2 0.8679  8.85   6.250x10-2  1 12   lb-in
 7.375x10-8 7.234x1-5   7.375x10-3 7.234x10-2  0.7375   5.208x10-3  8.333x10-2 1   lb-ft
 To Obtain
To convert a torque value from oz-in to N-cm multiply by 0.7062

Inertia

Multiply Number of
gcm2   kgcm2  kgm2  oz-in-s2  oz-in2  
 1 103 107  7.062x104 182.9  gcm2 
 10-3 1  100  70.62  0.1829  kgcm2
 10-7 10-4 1  7.062x10-3  1.829x10-5   kgm2
 1.416x10-5 1.416x10-2 141.6  1  2.590x10-3  oz-in-s2
 5.467x10-3  5.467  5.467x10-4  386.09  1   oz-in2
 To Obtain
To convert a rotor inertia value form gcm2to oz-in2 multiply by 5.467x10-3

Force

 
Multiply Number of
 kgf N lbf   
 1  0.102  0.4535  kgf
9.807  1   4.448  N
 2.205 0.2248  1  lbf 


 To Obtain
To convert kgf to lbf multiply by 2.205