I am planning to hang a projector which weighs 8lbs (~3.5kg), on a wall arm.
The arm weighs 4lbs (~1.8kg) and has a load capacity of 44lbs (~19.9kg), and I'll be hanging the projector at the arm's minimum extension (~12").
The fact that the arm is extended away from the wall adds leverage and therefore increases the effective force applied by the weight of the projector so as far as the wall is concerned, it's not just the 8lbs. I'm not savvy enough to calculate this though- perhaps someone can point me in the right direction?
I have (to be confirmed) found a 2" stud with a stud detector in what appears to be 1/2" or 5/8" drywall/plasterboard. I have some molly bolts, various size screws with rawl plugs available.
I am wondering
- If I put 2 screws into the stud and 2 molly bolts in the plasterboard would it likely hold?
- If it's not a stud, and I use 4 molly bolts, would it likely hold?
Commonly people suggest placing a board behind the arm it seems, but I'm hastened to do this as effectively the questions above still apply.
There's equal leverage, but it increases probability that I would hit 1 or more studs, or enable me to spread the molly bolts around a greater area.