Today i have been shopping for materials to make the screen frame, and this is what i have found out. for a 180" x 75" frame...
To have the basic frame made out of 1x3" aluminum welded... It is about $700
To make the basic frame out of Extruded T channel Aluminum... It is about $400 Here is the stuff I am looking at... http://www.automation4less.com/store/proddetail.asp?prod=650001
I saw where someone else did one a few years back on a smaller frame and used 1.5x1.5", and said that if you need more strength you could go 1x2"... Would I really need a 1x3 or should I go with the smaller size?
Pluses of the Extruded aluminum...
1:No need to drill and tap 80 holes for the pegs to hold the o-rings that connect the screen grommets to the frame
2: I can easily use "L" brackets to stand off the screen from a 2x4 frame behind the screen frame... Plus it means I don't have to use as large of a piece of aluminum as it is already supported to prevent sagging.
3: Cost of the aluminum is is 1/2 of the basic welded frame.
4: easy to attach a would frame to as it can be done with t-nuts.
5: Easy to locate the t-nuts in relation to the grommets.
Negatives of extruded aluminum...
1: buying 80 t-nuts, and corner connectors.
Pluses of welded frame:
1: Rock solid construction
2: Drill the holes for the frame anywhere rather than have to line up the screws with the "t" slots.
Negatives of welded frame:
1: Awkward to transport to our home.
2: Have to accurately drill, and tap 80 holes for dowels (or something for the o-rings to attach to).
So it looks like it is the most economical to go the Extruded Aluminum route for ease of construction, time, and price. I am thinking of using standoffs every 3-5 feet... I am thinking this will keep the frame true, and prevent the scree frame from sagging.
Does anyone see any possible problems with this scenario?