Thread: Help! Slope glider made out of Dollar tree foam board? View Single Post
Mar 04, 2011, 03:23 PM
Registered User
Fresno CA
Joined Jul 2006
1,747 Posts
Some details

If you open Steve's page and scroll down just a little, you'll see some drawings with a lot of info! Since we want something a little bigger to cope with the 5mm thick \$tree foam board lets enlarge every thing by 125%.

Lets start with the wing. Steve's wing is 6X24 inches. So we multiply 6 X 125 and get 750. Move the decimal point over 2 spaces and we get 7.50 or 7 1/2 inches. That's our chord. Next the span, 24 X125 = 30.00 inches. Now cut off a piece of foam board 7 1/2 X 30 inches. The crease need to be made by multiplying 1.8 X125 = 2.25 or 2 1/4 inches. Draw a line 2 1/4 inches back from the leading edge. Next we will lay out the ailerons. 1.5 X125 = 1.875 or 1 7/8 inches. Draw a line in front of the trailing edge 1 7/8 inches. Next find the middle and draw a line from the leading edge to the trailing edge. ( 15 inches) In the aileron area draw a line from the front of the ailerons to the trailing edge that is 1 inch from the center on both sides of the center line. This is now the bottom of your wing. Cut out the ailerons. they should measure 1 7/8 X 14 inches. Bevel the bottom of the ailerons about 45 degrees at their leading edges. Flip the wing over and re position the ailerons with the bevel down. Take some thin clear packing tape and tape the ailerons back in place with 1 piece of tape running from 1 wing tip to the other.Make 2 cuts at the aileron roots and fold the ailerons back over so they are laying flat on top of the wing. Run another piece of tape across the ailerons positioning it about 3/8 to 1/2 inch in front of the bevel. Cut the tape at the ailerons roots and fold the tape around the bevel, the flat edge of the wing then forward on the bottom. The ailerons should now move freely 45 degrees down and 180 degrees up.

Now back to the crease; first make a shallow cut in the foam, do not cut all the way through! Run the end of the spar along the cut . Carefully lift the leading edge up to form the crease. Next block the leading edge up 3/4 of an inch. Take you hot melt glue gun and inject glue the entire length of the crease and let cool. The leading edge should remain 3/4 up from the table when the 3/4 block is removed. Next lay the spar on the glue line and glue it in place with hot melt glue by stitch gluing, that's glue 2 inches then on the other side of the spar glue 2 inches then back to the first side and glue 2 inches. Just use a little bead here and you don't have to measure, but use enough to hold the spar in place but not so much that you build up excessive weight. Cut some slots front and rear of the wing so that it fits over you stick. Make the control horns from gift cards Mark the positions of your servos and make push rods. I use .039 or .047.

Sorry for the long post and not trying to HiJack your thread, Foam Crusher

Now that you know how to make the wing the rest should be easy.

Blue Skies...................Tim