I want to move a mass that weighs 100 lbs at 1 foot per second  
( apologies to the metric folks who do have their heads screwed on  
straight ) using a stepper motor.
I chose to accelerate at 1 foot /sec**2.  This means ( I think ) that  
the mass will go from rest to 1 foot/sec in one second and then  
maintain constant velocity.
A mass that weighs 100 lbs has a mass of approximately 3 slugs ( 100  
divided by 32 ).   Using F=ma ( 3 lbs = 3 slugs * 1 foot/sec**2 ) , I  
conclude I require approximately 3 lbs of force.
Is this correct so far ?

Now I am going to ignore friction. ( I have great ball bearings )
If I choose a stepper motor with pulley that has a 4 inch diameter,  
the circumference is pi *4 or approximately 12 inches ( 1 foot ).   
This means I would have to rotate the motor at 1 revolution per second  
( RPS).  The torque required of the motor is 3 lbs * 2  inches ( Force  
* radius )  or 6 inch-lbs.  This converts to approximately 100 oz- 
inches at 1 RPS.
Is this correct ?

Now I look for such a motor at DigiKey or Mouser or ???

MA

WFT Electronics
Denver, CO   720 222 1309
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