Is there a mechanical device that can push a large knob?

Hi everyone!

I’m always in the works of trying to smartify my central heating system. I’ve come a long way, but given that the boiler in itself is “dumb”, I can only get “so far”.

The boiler is operated by a large knob, that turns clockwise and anti clockwise for scrolling the menu, and then you push it to select/enter/start/stop. Pretty basic stuff

I would really like to find a device that can be automated to push this knob once, given certain conditions.

The boiler is connected to a smart plug with energy metering, and I want the “pushing device” to push the button when the power used (W) goes to a certain value.

I have checked out Switchbot and Fingerbot, but I think they are too small/have too short arms.

I’m looking for something with a longer arm, since the knob is kinda large, and it’s crucial that the device hits the center of the knob. If it hits it too far out, it would probably do nothing, or make the knob turn a little.

A solution with an arm/adapter/platform mod would probably work too.

The knob is pretty firm, so there should be some “punch” in the device.

I’m running HAOS, Zigbee2Mqtt through a Sonoff zigbee dongle. ESPHome would probably work too. But my zigbee mesh has better coverage.

Most grateful for any tips on hardware or some other solution, thank you! :slightly_smiling_face:




A servo motor maybe?

“rotary actuator” may prove to be a useful search term. Nope, that’s for turning knobs.
You want a push? A solenoid or servo motor is the best choice. Or a linear actuator.

Not sure if the torque is high enough.

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I think they would be better for turning than pushing?

Thank you for your reply!

Do you know of any solenoids or actuators that could be used “out of the box”?

I haven’t found a solution to this yet, would appreciate ideas

I’m updating here, in the unlikely event that someone will be in need of the same setup one day.

Turned out that it worked with a Fingerbot plus, hot glue and a hastily built rig to elevate the bot from the knob.

Automation is done through 2 temp sensors, when they reach a threshold value, the fingerbot will perform its magic and push the knob.

Magnets were added underneath the wood, for easy positioning of the fingerbots center.

Looks like crap, but it works! :slightly_smiling_face:

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