80/20 Aluminum Question

[kribbz]

For all the 80/20 guys here, I’m looking to use the 80/20 to build a light mount for my t5 fixture. It’s an aquatic life 48” fixture and will have 3 radion xr30’s in it. I’m figuring the weight to be about 31 lbs hanging. What I want to do is build 2 90 degree brackets coming off of the wall and suspending the fixture from it. The bracket needs to come about 24 inches off of the wall to suspend the fixture above the middle of the tank. I've got a few questions for you guys:

1. How do I figure out which brackets to use for the 80/20 to support the weight. I haven’t been able to find any load data on it.
2. How are you guys fastening the rail to the wall?
3. Do you put end caps on the 80/20 to cover up the exposed ends?


I'm new to this stuff so any help or pictures would be greatly appreciated! I put a mock up picture below so it explains what I'm trying to do. The black lines are the rail. The red is the bracket idea I have in my head and then the circle is a carabiner clip that i'm hoping I can fasten to the bracket.

 

[Quietman]

8020 has a beam deflection calculator. Assume Fixed One End and you can adjust load location or assume the worst case and put it on end of beam.

Make sure you're putting the anchors into studs. If you don't have studs in convenient locations then put a 3/4" support board in back crossing at least 2 studs and attached to them. Or you may want to go with hanging instead if the anchors are better.

 

[DMathys]

I did something similar to what you are doing but attached to the stand instead of the wall. Hope this helps.

1. I used a deflection calculator to figure out how much sag I would get and played around with different profiles until the sag was almost gone. No brackets or supports needed.

Beam Deflection/Displacement Calculator | 80/20 Aluminum Extrusions

Use this calculator to determine the deflection or displacement of 80/20 T-Slots profiles with one fixed end, two fixed ends, or a load supported on both ends.

8020.net

2. I have two holes through my 80/20 that connect to the top and bottom of the stand. I’m sure you do something similar and attach it to a stud or sturdy drywall anchor. Stud would be better.

3. I put end caps on the exposed ends that I could see. I think it looks cleaner. The exposed ends that are out of sight are open.

 

[apb03]

I have the same setup that you are looking to do. Here's a photo, and a picture of how I mounted it to the wall. I have 3 of the brackets holding it up.

I didn't make it myself, I contacted a local 80/20 distributor, sent a mockup photo such as yours and they made it up for me.