Making a Bungee Slope Plane Launcher

This is popular in Europe. We all hate those windless days at the slope. It is very easy to make a fast and high launch using a bungee cord. Go to a local medical supply store (or some hardware stores) and buy 25 feet of rubber surgical tubing. 3/8" OD works well. Attach a key ring at each end. I just loop the tubing though the ring and tape the ends together with a good amount of bi-directional strapping tape. Buy a corkscrew dog stake for the other end (about $5 at a hardware store).

Make a hard wood block about 4" long, 3/4" wide, 1/2" thick. Drill a hole though that will accept a threaded aileron wire. Cut the wire to about 3", make it into an "L" with about 1" bend on the theaded end. Attach to the block with nuts, Long end rearward and then epoxy the nuts.

Make a slot just forward of your wing in the bottom of the fuselage to accept your bracket. Glue it in with epoxy. You are now ready to bungee!

For the first attempts, you must make sure your plane is well trimmed and flying straight and level. Stake down the bungee securely, and slip the other ring end onto your "L". Pull back the bungee modestly for the first attempts. Release and let it fly off the ring before you do anything else. When you get it rocking it will look like this:

http://www.californiasailplanes.com/f20bungee.wmv

Have fun and be careful! Steve