Opener adjustment, arm length ?

[mister_two]

Just replaced an old Stanley opener with a Chamberlain CG40 and I have a question regarding the length of the arm that attach to the door, you know, the curve part that connects to the straight arm that connects to the trolley. Is it better to lengthen this part or to get it as short as possible ? If I get it as short as possible the straight arm part will extend beyond the curved arm and the manual says to cut the extra length - which is more work. Right now it works fine with the straight arm extending beyond the curve - it doesn't block anything. Is there any benefit to lenghten it as long as possible? Or to keep it as short as possible? It's not a heavy door, your regular single garage door, standard size, 7 feet tall I believe.

By the way, the chain that came in the box was too short. I had to call Chamberlain and they mailed me the correct chain. It took 5 - 7 busines days. And it took 7 business days to get here I asked if they could overnight the new chain and they said "no".

 

[daveroy]

If you make the arm too long... the door will be pulling in to the garage instead of up when the opener initially starts... I have seen this bow the tops of doors over time.

 

[koditten]

I agree with the bowing of the top of the door if arm is too long, but aren't you sapposed to have a stiffening bar going across the top of the door? At least all the doors I have with electric openers have this bar. The doors with no openers do not have this bar.

KO