add-a-motor overwinds and breaks the string!

[peartreehens]

Help! I put in an add-a-motor for my pop door. It worked fantastic for several months. Then one day, I went out and all the girls were stuck in the coop! The string had broken and so the door didn't open. I replaced the string. A week or so later, the replacement string also broke. I restrung it a third time, and moved the motor up to leave a lot of room between the motor and the top of the door, even when it's fully open. As I've watched since then, the door is opened slightly higher each day. Now the top of it is touching the bottom of the motor. I'm sure this is what happened the first (two) times . . . any one else have this problem? Just readjust the string in the morning and adjust the start/stop calipers?
thanks

 

[ChickensAreSweet]

I have to replace the string with the fishing line they recommend every 6 months or so, since I find it broke the string. I think this must be why mine keeps breaking too.

Mine are at least a couple of years old (I have two of them going). Actually one is new and one is a couple of years old. I had to replace one of them just recently as it stopped working. I bought them as a door package from a chicken supply company, so I kept the door and bought a new motor from Smarthome.

Hopefully someone will have the answer on how to prevent it. I told DH that even having to unscrew those screws and retie it a couple of times a year is still less work than going out twice a day to open/close the door at a specific time. But I would LOVE to know how to prevent it.

Here is my guess: the fishing line probably winds up around the spool at an angle sometimes, making it shorter in total length eventually? Maybe it gets hung a little. I have that problem with my weedeater spool.

 

[jetdog]

Mine has worked great for almost a year, I would say the problem is with the start and stop setting, maybe adjust it so it isn't winding up so tight and stops before it hits the spool.