Making a parachute

[CallumA]

Hi,
I'm building a weather balloon with some friends and we are wondering how we build the parachute.
We have decided to build one using nylon instead of buying one.
I have purchased 1m x 2m of parachute grade military nylon for about £3 but I haven't a clue how to build it.

The best idea on how I have thought of is cutting it into a hexagon, cutting a hole in the top and attaching string to each corner, will this be sufficient? If not, how should I do it?

Thanks in advance.

[256bits]

I also would recommend researching on how to pack a parachute so that when deployed it does so correctly. Nothing worse than free fall of your equipment due to a tangled parachute.

[CallumA]

Thanks, my friend's mum used to pack parachutes for a job I believe so we can ask her.

Is that the best way to build a parachute though? And should I let it free fall half way from the stratosphere then deploy the parachute?

[berkeman]

Hi,
I'm building a weather balloon with some friends and we are wondering how we build the parachute.
We have decided to build one using nylon instead of buying one.
I have purchased 1m x 2m of parachute grade military nylon for about £3 but I haven't a clue how to build it.

The best idea on how I have thought of is cutting it into a hexagon, cutting a hole in the top and attaching string to each corner, will this be sufficient? If not, how should I do it?

Thanks in advance.

Thanks, my friend's mum used to pack parachutes for a job I believe so we can ask her.

Is that the best way to build a parachute though? And should I let it free fall half way from the stratosphere then deploy the parachute?

We had a thread about this a while back. There are some real subtleties to trying to make a parachute work that high in the atmosphere:

http://www.physicsforums.com/showthread.php?t=437146

.

[RocketSci5KN]

You should research the options used in High Power Rocketry - there are some commercial sellers of chutes. If you value your cargo, I'd just buy something. You also need the knowledge on how to get the chute to deploy when you want it do. For very high altitudes, the best method is called dual deployment, where a small drogue chute is used for most of the decent, and then the larger main chute is popped out under 5000 feet AGL (above ground level). Otherwise, the item could drift for many tens of miles and the likelihood of recovery becomes very slim. You'll also need some method of tracking this, because you won't see it for long.