19 August 2024
5 August 2024
2 August 2024
An indoor model paraglider using Bienfang tracing paper
The intention is to make a small glider without rigid primary structure and successfully glide it in an indoor environment.
A real paraglider has no rigid primary structure, and yet it manages not to collapse upon itself because the sailcloth is stitched to form a ram-air structure. I don't want to even try and replicate it on a miniature model gliding indoors.
Let's replace the ram-air structure by changing the design and material. Firstly, make a single-skin sail from Bienfang tracing paper. To this single flat (and unstable) airfoil, we want to stiffen it chord-wise and we can do that by folding the tracing paper upon itself. Do it a few times and we will have as many integral paper ribs (without camber) as we wish. To these ribs, rig the underslung weight for balance and we are done.
An alternative method is to fold the single sail into an accordian stack and punch holes into it to allow rigging the underslung weight for balance.
Rigging the underslung weight
The weight is a piece of metal nut, washer or even a nylon foam wheel. The hole will allow the rigging lines to pass through, simplifying the tying of the weight.
For the moment, the rigging lines are designed to be identical and the most important aspect of each set of rigging line (fore and aft) is to hold the sail (relative to the weight) at the same pitch as the other sets. Making the rigging lines identical will be very time-consuming. A jig is therefore necessary and I am thinking of using paper stapler's staples to fabricate simple hooks.
