Join Date: Aug 2003
Location: sarnia, ontario, Canuckland
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I had some falcon screen AT material delivered and have begun the the build. I purchased 12' 2x8 and 2x4 lumber. I clamped the lumber together and let it sit for a week in the hope the lumber would acclimatize to the humidity and remain fairly stable.
Based on Aussiebob's calculator (props to him!) I came up with a 35.8' radius. My prefference would be to set up a trammel and physically mark the curve...and were it summer, that's how it would have been done. given this weeks temps of -40 deg C (with wind chill)...no screen is worth that, so i embarked on mathematically calculating the depth of the curve from the chord. A lot of googling, some help from some forum members and a couple friends (thanks Tosh's!!!), I got a formula and was able to build a chart, and then check it by graphing it. it worked! Even if you have never used the metric system, it may be worth trying it since working to the nearest mm is easier than calculating fractions of inches...and AB's excel spreadsheet allows you to input both metric and imperial units, so you can go between them at your convienience.
I printed depths for 5cm and 1cm increments from the center point...just in case. I ended up finding the 5cm increments enough. I then cut a strip of wood approx 1/4" by 11/4" x 11' and drove screws about every 20 cm used the wood to mark the curve...see pics below.
my plan is to cut out the curve and then attach a piece of lumber vertically to the curve that will act as the masking and and serve to stiffen the structure and lessen the chance to flex. I plan to rip the 2x4 on a tablesaw to the correct dimentions...likely 1/2" thick. the masking can only be 2 2/4" wide as that will yeild just enough room to slide my subs under the screen frame as i only have 82" height due to duct work, and the subs (laying on their sides...) are 22 1/4" high.
i purchased o-rings from amazon as well as a grommet kit and refils. My plan is to fold the falcon screen material over duct tape or a fabric stifening tape...(not sure what its called...and grommet through the tape and doubled over material. screws or bolts placed around the edge will act as anchor points for the o rings to tension the screen. this method of screen building and tensioning has been borrowed from some other screen builds.