Rigid Parachute

 11 August 2022

OK, a RAM parachute is cool. Packs neatly into a small bundle, but needs careful rigging and launch to be successful. And I don't want to spend too much time. Visually, it is just an arc off a cylinder and has lines hanging the weight below.

Making the foil

1. Make a card template of an arc and hot wire cut out a foam former.
2. Cut 4 strips of 2mm foam sheet, curl them to get close to the foam former.
3. Glue 2 strips together, using the foam former to hold it to the arc shape. Do likewise for the remaining 2 strips. Now we have a curled leading edge and a curled trailing edge.
4. Cut strips of 2mm foam sheet to form the 'ribs' and glue them to the inside of the leading and trailing edges. A curled ladder frame is formed. Maybe 4 ribs is enough.
5. Glue tissue to the outside of the frame, use the tissue so that the grain is running fore-aft.   

Making the motor base

1. Just a rectangular piece to mount the receiver, battery and 2 motors.
2. 4 holes at the corners of the motor base will be the rigging points.

Rigging assembly

1. Make a starboard and a port pair of lift lines to pass through the leading holes of the motor plate. Each pair is adjustable by lengthening or shortening with a stopper.
2. Similarly, 2 identical pair of pull lines is done for the rear pair of lines and passed through the trailing holes of the motor plate.