Polyaire to Honeywell/Eire damper motor adapter

thingiverse

This is an adapter plate and instruction to retrofit a Polyaire brand 24V AC damper motor actuator to where a Honeywell or Eire 240V AC spring return motor was installed. This allows reuse of old style ducts and air valves (dampers) with an economically priced Australian motor and zone controller. Apart from the 3D printed adapter plate, some metal hand fabrication is needed to make 6mm square drive socket (Polyaire side) to 8mm round shaft adapters (Honeywell/Eire side. I used 6mm square axle keys bough from a bearing supplier and M8 threaded collars bought from a local hardware shop. Collar was drill half way with M8 drill and half way with an M7.5 drill. 25mm of 6mm square key was then hammered into the narrower end. An M4 hex screw is threaded in the side to lock the collar to the damper shaft. This metal part could be 3D printed in ABS, but I think the strength across the 6mm square spigot would not be good enough for long term use. I might be wrong... Two M6 hole positions are provided for both brands of the old motors as they can have different offsets. A M6 bolt was used to hold the adapter to the original motors mounting bracket. Three M3 hex nuts can be press fitted into the pockets to retain the Polyaire motor with three screws in their original intended positions.