I don't know the rambo card but look on the schematic for a fan pin that is driven through a transistor. You can hook up a dc motor to this and control the speed with pwm the same as you control a fans speed.
You will not be able to run it in reverse with this.
Any spare pin can control an external FET to drive a motor as well.
You will not be able to run it in reverse with this.
Any spare pin can control an external FET to drive a motor as well.