Hi just got my arduino kit last week, now I'm trying to do something useful with the included 28BYJ48 stepper motor. Looking for advice on how to mechanically transfer power from the motor to actuate a ball valve. I was thinking I'd simply attach gears to each. I'd like to use something off the shelf if I can find it.
The valve, with handle removed, exposes a semi-round shaft for rotating the ball. Its basically a rod of 10mm diameter, truncated be 7mm in width between two flat sides. My hope is this is a standardized shape, and I can find a gear with a socket that fits this shaft.
The stepper motor exposes a similar shaped shaft, except of 5mm diameter and 3mm width. These motors seem quite popular, so I'd be surprised if there wasn't something that fit it.
Do these interface shapes have a particular name, or is anyone familiar with fittings for either?
If that stepper is strong enough to move the valve directly then it should be fairly easy to connect them. One simple solution would be a short length of brass tube (readily available from model shops and model engineering suppliers) with small bolts to clamp to the flats on the shafts. It may even be sufficient to crimp the tube. There is no need for a carefully balanced or perfectly concentric shaft/tube as there will be very little motion.
If the motor is not strong enough I suspect you will find it difficult (and/or expensive) to obtain suitable gears if you are not able to make your own, or modify some obtained from a scrap project.
You might also consider using a servo to control the valve. The programming would be a great deal simpler.
