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Hi all. I have only extremely basic knowledge in electrical matters. I'm converting this old Cuisinart food processor engine into a milk and curd stirring machine.

The problem is that it is way too fast (high RPM). I bought a voltage modulator (pic below) which slows it down somewhat but not enough.

What "plug and play" devices exist out there so that I can get full control of RPMs? Pics below.

Thank you and please - keep it simple.

Happy New Year

From the picture, that appears to be an induction motor rather than a "universal" motor (note the capacitor in the corner). Universal motors - the kind that have brushes in them, which you might see sparking a bit if there is any opening (ventilation) in that area - can be slowed down using the type of control that you have shown. Essentially, the speed of universal motors is controlled by voltage; the type of control you show effectively reduces the voltage (actually it clips off part of each AC cycle, but the effect is essentially the same.)

The speed of induction motors, however, is a function of the AC frequency. Using the type of control you show will reduce the voltage to the motor, which in turn will reduce the torque, which in turn may cause some slowing as the motor lags -- but this will greatly increase your likelihood of burning up the motor. You can control an induction motor using a VFD, a variable frequency drive, but most often these are made for and used with 3-phase motors, rather than the single phase motor shown. And you don't want to know the price.

Here's a better solution: Spend $15 on a cheap variable speed drill from Harbor Freight or similar importer. It already has speed control built in, and even has a chuck which can be used to grip the shank of whatever stirring device you want to use.

You will STILL probably want to use some speed reduction - you don't need the milk sloshing around, and even 15 rpms sounds scary fast -- but so slow for a drill / universal motor that you're going to bog it down. To get the best combination of high torque and low speed, you will ideally want a worm gear drive.

Ok. That was exactly what I was looking for. Thanks awake!

I'll look into the drill. My only question is how to lock the trigger on the drill so I don't have to hold it while it's stirring.