Specifications

20 Gear Drive, Plymouth Ind. Park, Terryville, CT 06786
Tel: [phone] Fax: [phone] http://www.amci.com
45
APPENDIX A
CHOOSING YOUR MOTOR
Sizing Your Motor
Your motor choice is based on the output torque you need, the mounting space you have, and your budgetary
constraints. Torque curves for all of AMCI’s motors are available on the following pages. There are a few
things to remember when choosing your motor based on torque curves.
1) The torque curves in this manual are for the SD17063. You cannot use these curves to accurately
determine the amount of torque from an AMCI motor when it is attached to a different drive. Nor can
you accurately determine the amount of torque from a motor when attached to an SD17063 if its
torque curves were generated using a different drive. In general, if a drives output bus is lower than
170 Vdc, then the available torque will drop off faster as speed increases when compared to the
SD17063.
2) Torque curves are shown with 200 steps/turn (full step) resolution selected. Higher resolution (half
step or micro-stepping) result in a ±10% deviation in the torque curves.
3) Make sure that the motor can provide the needed torque over the entire speed range of your
application. Available torque drops as speed increases, so evaluate the motor’s torque at its highest
operating speed.
4) As you can see from the torque curves, attaching a motor’s windings to the drive in parallel has the
advantage of more torque from the motor at high speeds when compared to attaching the windings in
series. The disadvantage is that the motor will always run hotter when connected in parallel so
additional cooling may be needed.
A simple guideline is to use the largest motor your mount-
ing space and budgetary constraints allow. Because the
I
2
R losses in the motor’s windings manifest themselves as
heat, the maximum allowable motor temperature limits the
motor’s current. Using the largest motor possible may
allow you to use a lower current setting on the SD17063
drive. This lowers the I
2
R losses, and the operating tem-
perature of the motor, which increases the motor’s life.
Determining Your Motor Current Setting
Your motor current setting is based on the amount of
torque needed from the motor. In many cases, the amount
of torque that you need will also determine how you attach
the motor to the SD17063. Connecting the motor wind-
ings in parallel will give you more torque at higher speeds.
For the SM34-650 and SM42-1250, connecting the motor
in series will give you more torque at low speeds. This is
because the limiting factor on the motor current for these
two motors is the SD17063 drive, not the motor. For the
SM34-650D, connecting the motor in series will give you
more torque for speeds below 420 RPM. (See figure A.6,
SM34-650 Torque Curves on page 47.) For the SM42-
1250, series connecting the motor will give you more
torque for speeds below 720 RPM (See figure A.7, SM42-
1250 Torque Curves on page 47).
SM23 - 90D
0
20
40
60
80
100
120
140
160
0 1020304050
Speed (RPS)
–– Torque (oz-in) ––
- - - Power (W) - - -
Parallel
2.8A
Series
1.4A
Figure A.1 SM23-90 Torque Curves
SM23 - 130D
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
" 
$ 
& 
  
 
 " 
 $ 
 & 
    !  "  # 
S p e e d ( R P S )
  T o r q u e ( o z - i n )  
- - - P o w e r ( W ) - - -
Series
1.4A
Parallel
2.8A
Figure A.2 SM23-130 Torque Curves