30 ms·
Re: sacrificial parts, I recently had to rebuild a two-car wood (read: heavy) torsion spring garage door system. The cleverest part was the plastic coupler [0]
by ethbr0 5y ago
Re: sacrificial parts, I recently had to rebuild a two-car wood (read: heavy) torsion spring garage door system.
The cleverest part was the plastic coupler [0] between the door-connected shaft and motor.
When the system originally locked up, the coupler broke. Consequently after restoring the system, I needed a $9 piece of plastic, rather than a $xxx new motor.
Made me sad that more modern things aren't designed with such value-protective degradation modes.
[0] https://www.amazon.com/LiftMaster-Coupler-Chamberlain-Craftsman-Garage/dp/B007VP7A5A https://www.amazon.com/LiftMaster-Coupler-Chamberlain-Crafts...
- a_mechanic 5y agoFYI motor couplings are not typically designed to fail as a method of protecting the motor. Overload protection is usually handled electrically, with fuses/circuit breaker which will remove power when too much load is applied to the motor (stuck door) or via controller board and load sensing. https://www.prairielectric.com/blog/how-do-circuit-breakers-protect-appliances/ https://www.prairielectric.com/blog/how-do-circuit-breakers-...