I wanted to have something big built for flitefest west and came to the conclusion that i wouldnt beable to finish my 200% ft-bronco in time as it has some new shapes i have never worked with before (hot cutting fuselage and tail booms). I have built several flying wings and was confident i could get that done in the time i had. So i designed up a 90" flying wing to hot cut from 2" wall insulation. When im all done i will post all the video i have taken, so for now just pictures.
My plan is to have it break apart into 3 pieces for storage and transport. This first build i am going to make it one solid piece to save time and to make it stronger for "landings".
The foam i am using is 2"x4'x8' and costs around $20. So this is about half of that or $10 worth of foam. The process is similar to cutting out foamboard. I print out the wing templates, trace them on the foam and cut them out with a knife. In this case the knife is a huge electrically heated blade.
For the airfoil i am going to use MH32. I simply grabbed the airfoil, imported it into inkscape and than scaled it up to the root chord of the wing which is 20 inches. Print it out and stick to two stacked pieces of aluminum flashing and cutout with office scissors. Take the stack to the drill press and make holes for T-pins.
On the airoil is a straight line down the middle which represents the angle of attack. I used a combination square to mark and record this line across the foam. This tool also allows you to perfectly mark mirrored spots on the other wing.
For the center section i took a rectangular block and put the templates on both sides. Than took my cutting bow and traced the templates. For the wing cores i use a pivot point setup. One end of the hot wire goes to a central "pivot". In my case a threaded rod glued into my work surface. Than line up the angles of the lines you drew on the wing so that both sides match up. Also when the hot wire is on the bottom of the airfoil, the wire should be perfectly parallel with the bottom of the foam.
For heat i like to use a 4s battery. It draws about 2.8 amps, so no worries about hurting the battery. The trick is to keep consistent pressure, constant movement, but go very slow....very slow!
I am using low temp hot glue for most all construction. For sparing i am using fiberglass kit rods. After inserting the spars i found some extra wood and gorrilla glued them in the back to reinforce the motor area. Than i sprayed super77 over the entire wing and applied uni-directional filament tape across top and bottom and than bi-directional filament tape around the entire perimeter.
To keep up to date you can follow progress on instagram: https://www.instagram.com/thenated0g/
currently in the build it weighs around 860g. I still have to add balsa elevons, maybe a coat of paint, and 5mil laminate over the entire thing. Im guessing final weight around 2.5kg
My plan is to have it break apart into 3 pieces for storage and transport. This first build i am going to make it one solid piece to save time and to make it stronger for "landings".
The foam i am using is 2"x4'x8' and costs around $20. So this is about half of that or $10 worth of foam. The process is similar to cutting out foamboard. I print out the wing templates, trace them on the foam and cut them out with a knife. In this case the knife is a huge electrically heated blade.
For the airfoil i am going to use MH32. I simply grabbed the airfoil, imported it into inkscape and than scaled it up to the root chord of the wing which is 20 inches. Print it out and stick to two stacked pieces of aluminum flashing and cutout with office scissors. Take the stack to the drill press and make holes for T-pins.
On the airoil is a straight line down the middle which represents the angle of attack. I used a combination square to mark and record this line across the foam. This tool also allows you to perfectly mark mirrored spots on the other wing.
For the center section i took a rectangular block and put the templates on both sides. Than took my cutting bow and traced the templates. For the wing cores i use a pivot point setup. One end of the hot wire goes to a central "pivot". In my case a threaded rod glued into my work surface. Than line up the angles of the lines you drew on the wing so that both sides match up. Also when the hot wire is on the bottom of the airfoil, the wire should be perfectly parallel with the bottom of the foam.
For heat i like to use a 4s battery. It draws about 2.8 amps, so no worries about hurting the battery. The trick is to keep consistent pressure, constant movement, but go very slow....very slow!
I am using low temp hot glue for most all construction. For sparing i am using fiberglass kit rods. After inserting the spars i found some extra wood and gorrilla glued them in the back to reinforce the motor area. Than i sprayed super77 over the entire wing and applied uni-directional filament tape across top and bottom and than bi-directional filament tape around the entire perimeter.
To keep up to date you can follow progress on instagram: https://www.instagram.com/thenated0g/
currently in the build it weighs around 860g. I still have to add balsa elevons, maybe a coat of paint, and 5mil laminate over the entire thing. Im guessing final weight around 2.5kg