I was warned that this kalk stirrer is loud. But didnt appreciate how LOUD the gearbox is. So I am on a mission to make it whisper quite. I purchased a small 42 stepper motor and a stepper controller to run the stirrer. So testing thus far I cannot hear the stepper motor turning at all. Im sure once its mounted I will get some vibration but right now the motor is silent when held in the hand. So its a good start and looks like it will fit in the housing by drilling a couple of new mounting holes. The only minor thing I have to solve is the shaft on the stepper is slightly smaller than the gearbox, however I will simply create a shim. So its nearly a direct swap as the controller can be set to rotate the stepper when power is applied (12VDC) and the knob sets the speed. Here are some pictures of where its up to.