I’m in the process of building a small brewery in my garage and I want to automate the whole thing. I was shopping around for valves with actuators and they are super expensive. The valves alone are much less expensive than the valve+actuator combo, around $50 http://amzn.com/B0088XLQCM, so I’m hoping to reduce costs (and do a fun project) by designing and building the actuators myself.
A friend of mine suggested Pololu as a source of geared motors and controllers that could probably do the job. I’m a member of the Synshop hackerspace in Vegas and will probably 3D print an adapter for attaching the drive unit to the ISO-5211 mounting pad on the valve and I’ll machine a small adapter between the drive shaft and the valve stem. I’ll be adding limit switches too, if necessary. My question is which of the geared motors on Pololu do you think would be best for this application?
That sounds like a cool project. Without knowing more about your system, it is difficult to narrow down an appropriate selection of gearmotors that would work. To start your design, you’d first have to characterize how much torque you would need to turn the valve stem. (If it is a relatively large torque, you might have to set up some sort of lever arm system to gain mechanical advantage and reduce the amount of torque you would need.) In general, we recommend running our gearmotors at 10-30% of their stall torque. For higher torque applications, I recommend using our metal gearmotors (as opposed to our plastic gearmotors).
Once you find an appropriate gearmotor, you could pick a motor controller that can continuously handle the maximum amount of current that motor would draw in your system. You can find all of the motor controllers we carry here.
Thanks for the reply. I’ll order one and use a torque meter to measure the torque required to turn the stem.
If it wasn’t clearn, the valve in question is this: amzn.com/B0088XLQCM
I haven’t been able to find any engineering data for the valve that lists the precise turning torque. The amazon listing just says “low torque”. For those following along, I’ll post again when I have the valve in hand and have measured the torque.