"Paolo,

As explained in my previous post, that is really too much of a turn down of 200:1. At lower voltages and you get significantly lower torques (square law). It may well rotate at those low rpms but you may well find you have to increase the voltage to get the dolly moving and then lower the voltage to get the right speed. As you need smooth operating, pwm controllers have discrete step sizes and depends on the controller. They may have 100 or more steps and whilst these steps will be less noticable at higher speeds, at lower speeds they will be quite evident. Manufacturers do not always specify the number of steps in their pwm controllers including this one.

Using closed loop control with a speed feedback can help but the solution we would use is with a stepper motor. However, we have used dc motors for variable speed camera panning with reasonable success with > 100:1 speed turndown but had some fancy custom electronics behind it. "

– Admin

"Paolo,

If you are referring to the 950D 1450-102 then yes, it will work as the motor draws less than 1A at nominal load.

You did not state the voltage you will be running at as rpm is basically proportional to voltage but at 12V, this motor has a rpm of 1145, 5 rpm would mean a turn down of 230:1 which means a voltage of 0.052V so no, you will not get a rpm of 5.

For low rpms, simplu use a motor with a higher ratio gearbox such as the 810:1 version."

– Admin

"Luke,

The most important thing to ensure is that the power supply is not a switchmode type, (MFA refers to this as a digital type). You really must use a linear power supply, I would not get too concerned by half or full wave rectified. You should ensure that the power supply can take the motor starting current as well as well as its full load current."

– Admin