What size of parachute for this rocket?

[WarrenW]

Hi Everyone,

I have started my rocket that uses BT80 tubes at a height of 36 inches and a 3-cluster of C6-3 motors. This will carry an egg although I have not yet built the container to carry the egg. It will be something with a lot of cotton! The nose cone I ordered for it is plastic and seems heavy. So now I need to build a parachute. I read some other posts on here as far as what to use. I don't have much time to shop around since this will be launched this coming Saturday. Someone posted that they used a 0.3 mil clear poly paint drop cloth from HD. How big would I want the parachute to be from one side to the other? The container holding the egg will be blown out with the nose cone so would I connect the shock cord from the tube to the egg container and then to the nose cone? Where should the parachute lines connect to?

Thanks!

Warren

[H_Rocket]

How much does it weigh (with the payload)?

[gary7]

Quoting Handbook of Model Rocketry 7th Ed

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"The parachute size to use can be determined by a basic rule of thumb: A parachute should have 44 square inches of canopy area for every ounce of recovered weight."

Of course you have to consider how far you are willing to let it drift with a larger chute for recovering a rocket that will be more intact or keeping the drift to a minimum by using a smaller chute in which case you risk rocket damage because it came in too fast.

There are more considerations than chute size too, like type of material used, weight of rocket, vents in the chute, shroud line length and more. Read the Handbook quoted from here, chapter 12 starting on page 179.