I'm planning to use a Moteino but I wasn't sure if this question belongs to the Moteino topic so I posted here. My question is, does anyone have suggestions or experience with driving small faucet-type (turning knob) radiator valves? It's not the more recent pin-type valve - for those there are a lot of ready-made solutions. One thing I'm not sure about is the torque needed to turn the knob from a stall (and then keep it turning with a lower torque). This type of gear motor is an example ow what I'm thinking of using: https://www.exp-tech.de/en/motors/dc-motors/9606/120-1-plastic-gearmotor-offset-output
Thanks for any ideas.
Will these have to be unintrusive?
Or will they mount inline to the pipe?
There are valve motors on ebay (https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313.TR5.TRC0.A0.H0.Xmotor+valve.TRS0&_nkw=motor+valve&_sacat=0) of all sorts of sizes which are inline and more expensive than the 6Euro motor you linked. But I imagine they are more appropriate for the task.
I don't want to break the water flow as it would require emptying all the radiators of the system, etc, it would require an order of magnitude more work and inconvenience for everyone. I want to make a solution that I can mount on the faucets and those would turn the existing knobs externally. The electronics and driving is pretty simple, but I need to choose a suitable DC motor that I can run from batteries.