Circular Bin-Liner Parachute

To familiarise yourself with the principles and problems of using parachutes, make this parachute which does not require any special sewing skills.

Right click and select Zoom in to see clearer.Materials and equipment

For this parachute (and its drogue), you will need . . .

  • a large bin-liner;
  • gaffer tape;
  • around 20 metres of light nylon cord;
  • a mug of cold water;
  • a knife;
  • a small open flame (like a candle)
  • 2 plastic rings (about 2cm diameter); and,
  • 0.3m elastic cord.

Shroud

The shroud is very easy to make. Simply take a bin-liner (a wheelie bin-liner - 250 litre - is good for this. You want a reasonably thin and flexible sheet so don't use garden refuse bags) and slit it across the bottom and down one side thus making a flat sheet and lay it flat on the floor.

Pick it up from a point that is halfway between the sides that are closest together and the same distance from one of the other two sides (where the green lines cross on the diagram). By doing this, you will get the largest area (outlined in purple) and have the most spare to make a drogue chute.

Next, make a really good job of gathering the sheet in, pulling it down along its length until, you have in one hand the centre (green) and the in the other (at a distance between your hands, equal to the radius of the required shroud), the outer rim (purple).

Then, using a bread knife or other sharp, long bladed knife, cut through the gathered end at the desired position and then again an inch or so from the green end - this latter cut will make a hole in the parachute that will increase its stability in decent.

When you lay the shroud out flat on the floor, you should have a circle around 3 to 4 feet in diameter with a 2" hole in the middle. Now, from the remains of the original sheet, you can repeat the process, making a drogue of around 1.5 feet in diameter with a 2" hole in the middle.

Cords

Right click and select Zoom in to see clearer.Take the nylon cord and cut off roughly 2 metres - placing this to one side. To the remainder, fold it in half, then in half again and so on until you have 8 lengths, just over 2 metres long. Cut it into these lengths and seal the ends by melting in a flame for a second or two and then putting the melted end into the mug of cold water (left). Instead of using a knife or scissors, nylon can be cut by putting it in a small flame thus automaticaly sealing the ends.

Take one of the eight pieces and fold in two, forming a loop. Thread the loop through one of the plastic rings and then pass the two loose tails through this loop. Pull tight, tie a knot (not to stop it from coming undone but just to provide a bit of resistance) and repeat for the other seven lengths. You should now have sixteen ends coming from one plastic ring. Then tie the elastic to the ring (as in the photograph) - tying a knot in each end so as to stop fraying.

Now, tie a knot in the end of each of the cords - this will stop the cord from slipping from the shroud.

Now, make a smaller one with six or eight cords around one foot long for the drogue.

Assembly

Place the plastic ring in the middle of the shroud and lay out the cords so that they intersect the edge of the shroud at equal distances. Make sure that the cords are in the order that they are on the plastic ring as this will make it easier to sort out any tangles that you may get into later on in the field. It is easiest to do this by laying them out and then taking opposite cords and laying them out at opposite sides. Then count four cords and place that one half way. Right click and select Zoom in to see clearer.Then divide in two again and so on until you have all sixteen cords laid out equally.

Then, place the knotted end near to the edge of the shroud (half an inch) so that the cord goes away from the centre as it would during the decent. Then put a piece of gaffer tape on (about a 1" length) and press down firmly. Repeat for the other fifteen. Now you have your main chute.

Repeat, using the same techniques for the drogue.

Test the chutes by carefully pulling them along. You should see that they produce a fairly good hemispherical shape and a lot of drag.

On to the Pictures . . .


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