Garage door opener question?

[Lloydthumper]

On a standard chain driven garage door opener what tells it where to stop when opening. I have worked on industrial roll up doors with cams inside of it to set the stops for up and down. But what I am wanting to do it use a standard garage door opener on a roll up door by fabing a bracket and hanging it on the side and puting a sprocket and chain on it. I found a guy that has two working openers for $30 each Used of course. But my doors are 10x10 and I don't want to get the openers and them not open it high enough. Any one know the answer to this I have seen the little setting screws on the side of some openers to adjust the height but I was wondering what kind of range this has or can it be adjusted up to a 10' tall door thanks Lloyd

 

[Jay H 237]

The chain drive Allister openers that are in my parent's garage have "cams" attached to the chain. There are limit switches attached to the top of the opener near the drive sprocket. As the chain moves around the sprocket the cams hit the switches stopping the unit when the door is all the way up or down.

 

[kbs2244]

You can adjust where those switch triggers are on the chain.
You can also splice in more chain and make a longer track for extra travel.

 

[nova65ss]

What brand is it? On a LM or Craftsman it has limit switches inside that you move back and forth to adjust the travel. If you pull the cover off you can't miss them. They will also lift up to at least a 10' tall door no problem. Smoe do have chain "dogs" some people call them that you attach to the chain and trip a switch when it goes past.

 

[astondb9]

Wayne Dalton brand perhaps.