I built this Launcher using simple stuff available from most hardware stores.
A length of 32mm drainpipe, length of your choosing.
2 steel threaded rods M8 with 8 nuts
A fence lock with a latch system (as seen in the video)
a wooden plank with at least the width of the fence lock
A long steel rod (like concrete rebar) cut into 3 pieces, 1 short 2 long
strong nylon rope
2 round hooks wit a threaded end
3 strong keychain rings
a ground anchor
Bungee cord (http://www.hobbyking.com/hobbyking/st...)

If desired you can 3d print the bungee hook I designed
(http://www.thingiverse.com/thing:1506861)

Cut the drainpipe down the middle and drill a hole in each end for the M8 rods to go through and attach them.
Cut the plank in 2 pieces of about 60 cm and stack them on top of each other.
Take the 2 longest lengths of rebar and put them at each end between the planks and put the short end in the middle.
put in 2 screws on ech side of the rebar to clamp them between the planks and screw the tightly together. Put the fence lock in the middle with the short rebar between the planks and screw it all down.
Pull the bungee cord through one of the keychain rings and put a threaded hook in each end of the cord and lock them down with cable ties. put the second keychain ring through the threaded hooks.
Tie a piece of nylon rope to the ring and make a loop at the end to pull your plane.
take a longer piece of nylon rope and tie it to the ring. Tie the 3rd ring to this rope and leave this piece longer to be adjustable in length. Take a heavy screw or bolt and tie it to the end of this rope (so it stays low on launch, or it might catch your prop) which can be used as a safety pin.
all done!! happy flying.

Questions? put em below.