6 inch servo controlled baffle

thingiverse

I have forced air in my home, but it's not zoned so the basement gets cold. Zone dampers are too expensive so I designed my own dampers and added a second thermostat all controlled by an Arduino and relays to open and close the dampers depending on which thermostat asked for heat. It's a work in progress so I don't know if my idea will work as I intend and it may create unwanted back pressure in the system. But, I like to tinker so it's worth a try. If the gear for the SG90 fits too tight just increase the print size by a couple percent. The damper was made from a 6 inch pipe and manual damper control. I drilled a second hole in the pipe for the servo pivot rod. The manual damper only has one pivot rod so I made the second one from a 1/4 x 20 bolt with its head cut off and a slot cut in the center of the other end. I also drilled and tapped a 8-32 thread to secure the second rod to the baffle plate with a screw. The large gear also has a 8-32 thread to secure the gear to the shaft with a screw. The large gear screws onto the cut off bolt. The whole thing is held onto the pipe with 2 - 1/4 inch and 2- 3/4 inch metal tapping screws. I can't recommend what relays or code for your Arduino you should use since furnaces and thermostats will differ from mine.