Make the Timer
Cut out two plastic circles larger than the diameter of the timer gear.
Drill a 1/8 hole in the center of the inside plastic circle. Sand a
rough flat spot on both sides of the timer gear. Very carefully CA glue
the inside plastic circle to the inside of the gear. Clean out the
plastic from the hole so the gear easily snaps back onto the timer. CA
the solid plastic circle to the outside of the timer gear. Drill a 1/32
hole in the side of the timer gear and CA in the timer pin. Careful when
gluing in the timer, apply glue to the taps only. Never get any glue on
the center of the timer.
Thread the Timer Line
Use monofilament fishing line, about 8lb test. First tie and CA one end
to each launch pin. Then thread the line around the center pin and
forward to the timer. Pull the two lines forward and taught to the
timer. Verify one last time that the wings are swinging smoothly. Use a
cloths pin to keep the wings closed and pull taught the two lines. Wrap
around the timer and mark a spot on the lines at about the 6 o'clock
position. Tie an open circle knot at this position and CA the knot. Now
trim the line at about 1/2 pass the knot so you have something to help
place the knot over the timer pin. Adjust as needed so that the wings
snap open in 2.5 to 3.0 seconds.
July, 2017 - Just tried this way... First make
about 5 small loops in the monofilament line, I just tied them around a
1/8 rod. This gives you a choice of which loop to use. Pin the set of
loops to the fuse where the set timer should be. Thread the lines back
thru the fuse and out to the launch pins. Mark the lines with the wings
closed. Tie at the marks to each launch pin. CA all knots.
Glue in a 1/16 wire pin for the rubber catapult.
First install the timer on the right side of the fuselage. The timer
will face you as you launch. Reverse the line threading in Figure #1 on
the plan so that you can hold the catapult in your right hand and hold
the plane in your left hand.