I knew physics class would come in handy someday.

I was looking at stall torque to choose that motor, the other ones on that site seemed to weak to get the arms up. I don't seem to see that specification on most of the other motors I looked at.

Torque isn't important for the arms to raise (assuming low friction), only angular velocity. To get up to speed quickly you do

need more torque - so how quickly do you want to change angular velocity?

Multiply that rate by the moment of inertia and you get the torque required (all SI units

of course). Little maths refresher might be required for those MoI calculations of course

Oh and whatever routine torque you want the motor to supply should be quite a bit less than the

stall torque of the motor, perhaps a third or less, in order to prevent it struggling (or excess strain

on the gearing).