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Bruce Hansen's 1946 Erector Parachute Jump

Bruce writes: "This model is the early style (1940-1948) Parachute Jump built from a 1946 9½ set. What makes this 9½ set unique is the blue paint used on the CS wheel segments. The finished model is about 5 feet tall.

The concept of the model is quite simple. The parachutes run up/down on a fixed string tied between the top of the tower and a board at the base. The NT cones run up/down on the same string as the parachuters. The cones are raised by a separate piece of string running over pulleys at the top of the tower and down through the tower to "drums" made from Z flanged pullies and W stacks attached to the motor.

The cones drop from the top of the tower when the motor is manually shifted to neutral. The relatively heavy cones drop in about 2 seconds and the top of the parachute wedges in the cone. The motor gear box is shifted 'on' and the cones with the parachutes attached start to raise. A BL washer is strung through the parachute string near the top of the tower. The cone passes over the washer on the way up; when the parachute contacts the washer it separates from the cone and drops. The motor is then shifted to neutral at the top just before the NTs bottom out on the tower. I put my finger on one of the drums to keep the cones from dropping until the parachutes touched down.

Here's a shot of the top of the tower. The string from the motor drums goes up through the center and passes through a "CR" turret plate with hub in the center. The string continues up and over P7 pullies and down over AQ pullies to the NT cones.

I mentioned the concept of the model was quite simple. However, the execution is very finicky. My problems with the original design and improvements were:

  1. Parachutes hang up on the string when they rise/drop. I tried waxing the string which helped some but I found monofilament fishing line to be the best fix.
  2. Cones hang up on the BL washers at the top. I ended up tying a piece of rubber band around the string at the top instead. The cone easily passed over the rubber band knot and the 'chutes dropped as intended. I still used BL washers at the bottom of the string/fishing line.

My success rate of lifting the (4) parachuters and dropping them from the tower's top went from about 5% to 30% with the design changes. That's probably why Gilbert changed the design in 1949 to the more reliable OH/OI gear system as pictured in Dr. Prune's parachute jump. Just for grins, here's a shot of the 1946 9½ set used to make the model. The early version parachute jump plans are available from Downloads page on this website."