3 ms·

A design with limit switches instead of counting turns seems like it would be much more reliable. e.g. https://www.floweringelbow.org/automated-door-from-an-old

A design with limit switches instead of counting turns seems like it would be much more reliable. e.g. https://www.floweringelbow.org/automated-door-from-an-old-windscreen-wiper-motor/ https://www.floweringelbow.org/automated-door-from-an-old-wi... That way the software can be nearly stateless: 1. Check time and determine desired state (open or closed) 2. Compare desired state against limit switches and run motor until the limit switch is hit (or it times out which is an error) On the other hand, a turn-counting strategy can lose power in the middle of opening or closing and "forget" where it is in the process.

hedora 3y ago
Chickens are incredibly dirty animals. The limit switches would probably be fouled (fowled?) pretty quickly. Commercial versions of this can measure motor load (via current), but still require manual calibration. I wonder if they thought they could get away with manual calibration, but couldn’t make it reliable. I think these people are the market leaders: https://www.chickenguard.com/ https://www.chickenguard.com/ Note that the commercial version latches the door shut, so raccoons can’t open it from the bottom (they would have to learn to pull the string, and then also stick a hind leg or something in the bottom to wedge it open after the string was released). The new 2023 model replaces the string with what appears to be a high tolerance gear system. That auto-calibrates once, then remembers the set points.
- mtreis86 3y ago
  Limit switches for all sorts of terrible environments exist. These would probably work https://www.mcmaster.com/products/switches/environmental-rating~ip68/sealed-limit-switches/ https://www.mcmaster.com/products/switches/environmental-rat...
  - wiredfool 3y ago
    I used something like this: https://www.mcmaster.com/products/lever-switches/subminiature-snap-acting-switches-9/actuator-style~roller-lever/ https://www.mcmaster.com/products/lever-switches/subminiatur...
- Symbioquine 3y ago
  Yeah, it would be interesting to get an update on FloweringElbow's implementation to see how often the lower limit switch is getting fowled :p . I think it's also possible to design it such that both upper and lower limit switches are placed higher up on the edge of the door, rather than strictly at the top and bottom, which should help with the fouling. Practically though, any automated system will be vulnerable to fouling/blockage and require regular maintenance to keep the mechanism clear and clean enough to avoid premature corrosion (chicken poop being pretty acidic). In my opinion, it's a pipe dream to have a fully automated coop in a backyard setting and not eventually/occasionally have failures that require manual intervention or lead to neglect and losses due to predation. Better to think of such systems as tools to relax the timing requirements for manual care. Instead of doing all the work at the right times, one can confirm that the animals are out/fed/watered/in/etc as part of doing the normal morning/evening rounds/chores.
- bagels 3y ago
  Problems I've had with the chickenguard (I still use it, and probably won't stop, it's good enough with modifications) The tracks will get warped over time if exposed to moisture. I don't live in a particularly wet place, and it's partially covered, but the wooden tracks warped, and the door would get jammed. The string will get tangled and quickly finish off the batteries if the door is jammed or the batteries get low. Modifications made: I routed a painted solid wood doorway to provide a wider track to prevent the track from warping, and to improve tolerance to dirt, leaves and twigs, which has eliminated door jams. Battery replacements every 6 months are now on my calendar.
  - hedora 3y ago
    Interesting. Our tracks are plastic. They must have improved it. I did have to disassemble it and untangle the string from the spool and motor once after initial setup.

hedora 3y ago

Chickens are incredibly dirty animals. The limit switches would probably be fouled (fowled?) pretty quickly. Commercial versions of this can measure motor load (via current), but still require manual calibration. I wonder if they thought they could get away with manual calibration, but couldn’t make it reliable. I think these people are the market leaders: https://www.chickenguard.com/ https://www.chickenguard.com/ Note that the commercial version latches the door shut, so raccoons can’t open it from the bottom (they would have to learn to pull the string, and then also stick a hind leg or something in the bottom to wedge it open after the string was released). The new 2023 model replaces the string with what appears to be a high tolerance gear system. That auto-calibrates once, then remembers the set points.

mtreis86 3y ago
Limit switches for all sorts of terrible environments exist. These would probably work https://www.mcmaster.com/products/switches/environmental-rating~ip68/sealed-limit-switches/ https://www.mcmaster.com/products/switches/environmental-rat...
- wiredfool 3y ago
  I used something like this: https://www.mcmaster.com/products/lever-switches/subminiature-snap-acting-switches-9/actuator-style~roller-lever/ https://www.mcmaster.com/products/lever-switches/subminiatur...
Symbioquine 3y ago
Yeah, it would be interesting to get an update on FloweringElbow's implementation to see how often the lower limit switch is getting fowled :p . I think it's also possible to design it such that both upper and lower limit switches are placed higher up on the edge of the door, rather than strictly at the top and bottom, which should help with the fouling. Practically though, any automated system will be vulnerable to fouling/blockage and require regular maintenance to keep the mechanism clear and clean enough to avoid premature corrosion (chicken poop being pretty acidic). In my opinion, it's a pipe dream to have a fully automated coop in a backyard setting and not eventually/occasionally have failures that require manual intervention or lead to neglect and losses due to predation. Better to think of such systems as tools to relax the timing requirements for manual care. Instead of doing all the work at the right times, one can confirm that the animals are out/fed/watered/in/etc as part of doing the normal morning/evening rounds/chores.
bagels 3y ago
Problems I've had with the chickenguard (I still use it, and probably won't stop, it's good enough with modifications) The tracks will get warped over time if exposed to moisture. I don't live in a particularly wet place, and it's partially covered, but the wooden tracks warped, and the door would get jammed. The string will get tangled and quickly finish off the batteries if the door is jammed or the batteries get low. Modifications made: I routed a painted solid wood doorway to provide a wider track to prevent the track from warping, and to improve tolerance to dirt, leaves and twigs, which has eliminated door jams. Battery replacements every 6 months are now on my calendar.
- hedora 3y ago
  Interesting. Our tracks are plastic. They must have improved it. I did have to disassemble it and untangle the string from the spool and motor once after initial setup.