Kelly
Usually remembers to get the pointy end up
I was trying to pack a parachute to fit into a 7" by 38mm bay (love those units!), and I wasn't happy with the nomex blankets I had - too bulky, or too small. I had a chunk of Nomex, so I started to think about and experiment with different shapes to see what would be closest to 'ideal'. Eventually I arrived at a triangle shape, which I'm just calling a 'nacho' blanket. Here's how I arrived at the sizing for this blanket.
First, I wanted a piece that would wrap completely around the chute, so it need to be 7" long and pi * diameter wide:
Next, I wanted a chunk on top to overwrap, provide better protection, and keep it all together. I decided to make this triangular (to minimize fabric), and be long enough to wrap once around the circumference again:
Finally, the ends needed wrapping, so I added a couple triangular chunks (to minimize fabric) on the ends, these need to be about pi * radius long to wrap around the end, plus a bit to hold it together, so I just made it pi*diameter long:
And that's the nacho. The sloping lines forming the sides of the lower and upper triangles roughly formed a straight line, so I just made it so. I cut off the left/right corners as well, just to get rid of some fabric. Here's me wrapping a parachute:
The Nacho measured 14" wide across the bottom (after trimming the corners), and about 9.5" tall. If I had used a square wrap with the same amount of cloth, it would have been about 8.5" square (about 12" on the diagonal), and would have wrapped around the chute more, but would not have as much material on the ends (which, I think, is where it is needed most). Also, note that this is not just a square cut in half, as the angle at the top is not necessarily 90° - it depends on the length vs. diameter.
Anyway, it seems to wrap my chute pretty well with a minimum of material, and so this is probably how I'll make my blankets from now on.
PS don't fold your parachutes like you see here - I pretty much just wadded up a 'chute to demonstrate the wrap.
First, I wanted a piece that would wrap completely around the chute, so it need to be 7" long and pi * diameter wide:
Next, I wanted a chunk on top to overwrap, provide better protection, and keep it all together. I decided to make this triangular (to minimize fabric), and be long enough to wrap once around the circumference again:
Finally, the ends needed wrapping, so I added a couple triangular chunks (to minimize fabric) on the ends, these need to be about pi * radius long to wrap around the end, plus a bit to hold it together, so I just made it pi*diameter long:
And that's the nacho. The sloping lines forming the sides of the lower and upper triangles roughly formed a straight line, so I just made it so. I cut off the left/right corners as well, just to get rid of some fabric. Here's me wrapping a parachute:
The Nacho measured 14" wide across the bottom (after trimming the corners), and about 9.5" tall. If I had used a square wrap with the same amount of cloth, it would have been about 8.5" square (about 12" on the diagonal), and would have wrapped around the chute more, but would not have as much material on the ends (which, I think, is where it is needed most). Also, note that this is not just a square cut in half, as the angle at the top is not necessarily 90° - it depends on the length vs. diameter.
Anyway, it seems to wrap my chute pretty well with a minimum of material, and so this is probably how I'll make my blankets from now on.
PS don't fold your parachutes like you see here - I pretty much just wadded up a 'chute to demonstrate the wrap.
