Liftmaster 8500 compatability

[michaelg]

Gentlemen,

I am considering the Liftmaster 8500 jackshaft door opener after reading the stellar reviews on this forum. In doing my research I also looked up the manufacturers requirements and noticed that the opener is made for doors with drums between 4" and 6". Looking at my door the drums are less than 4" and closer to 3". I have a new Clopay door that measures 13' x 7'. Is the smaller drum size incompatible with the Liftmaster 8500?

Thanks for your help,

 

[AndyL]

Basic answer - maybe.

I've done 3800/8500s on the clopay 3½" drums and it hasnt been an issue. However it may not fit as you might expect.

usually clopay uses the flags for 4" drums - in which case theres no issue (measuring out from mounting surface you'll probably be 2⅜- 2½" to shaft center)

occasionally they use the correct offset plates - which doesn't allow the 3800 to fit, but if your more typical construction - with a 2x4 that protrudes from the drywall - you just need to modify the lower mount, and stay on the outside of the 2x4 the doors mounted to.

The door does run slower, which isnt a bad thing, you will have some fun fitting the cable tension monitor without having the top section rip it off the wall; but its not impossible...

 

[Palnud12]

Andy,
I am new on this site and I am having the same problem with my Clopay door running into the cable tension monitor. What do you do to solve this problem?
Thank you,