I am making about a dozen rotating pedestals for a large store display
window.  Still working though some of the engineering issues.  They
are going to run though a series of states during the day and at
certain times doing different routines. ( Lighting is also going to be
automated.)  The turntables all need to be individually controllable.
So was thinking of using the HB-25 controller from Parallax (available
from Solorbotics as well). http://www.parallax.com/tabid/768/ProductID/64/Default.aspx
and an Arduino Mega 2560.  With a PC running Max MSP as the "brain".

The pedestals are going to range from 12 inches to 7 feet (So I am
going to need a variety of motor sizes) and I need to control the
speed and direction.  Ideally I would like to have them range from
very slow to something in the neighborhood of a vinyl record speed. So
0-1RPM to approximately 45 RPM.

Was wondering if anyone has had experience with controlling DC motors
in this way and or making this kind of mechanism.   Want to make a
good estimate on the necessary motor strength and speed control ranges
when choosing the motors. Would like to order parts for the first
tests tomorrow.  Pedestals are going to be on swivel bearing plates
and could use a combination of cable, belt or gear driven mechanisms.
Some gearhead motors I have found might work great for the smaller
ones. http://www.allelectronics.com/make-a-store/item/DCM-351/24-VDC-GEAR-M...
Was thinking that the larger (7 foot) might need to have a steel cable
drive mechanism and larger motor?.  Hoping the HB-25 can handle that.
It can do .5 HP at 25A with a 6 - 16 volt motor.  Was thinking that
should be enough as long as the bearing spinning mechanism is smooth
and has low resistance.

Any one have any ideas or insight?

Best,

Luke