I haven’t come across any threads relating to jackshaft style door openers while I was searching for some installation tips, so I thought I’d share what I ended up doing. In my case, I have a Liftmaster 3800PC opener, and of course being a jackshaft style, the opener is mounted beside the garage door (there is an overhead unit, but it’s really just a remote light - the switch wiring terminates to the unit mounted beside the door).
The install couldn’t have been any easier, this is dead simple
Here is the opener:
Here is the garadget device - it’s pointed directly at the side edge of the garage door. My switch wiring was right there running up to the opener unit, so I tapped in there along the run.
As you can see, the reflector is attached directly to the side of the door itself, probably 3-4" away. I cranked the sensitivity threshold up to 70 since the reflector is so close, but I also angled the garadget a bit so that when the door is open, it isn’t firing directly across where something else might reflect back, and instead it ends up hitting the wall on the other side of the garage about 3 or 4 feet inwards of the door.
That’s all there is to it, hope this helps someone else installing with this style opener.