Doubt regarding parachute

[Dratinia18]

Hello everyone, hope everyone's doing good! So today finally came the day to start thinking and designing the parachute for my rocket. First of all some details, It is a 140cm high rocket roughly weighing 2kg, We are expecting it to reach an apogee of 800m and a velocity of 0.5 mach. So here are my questions -

1. Should I make it out of stock nylon, because I already have it?
2. What size should I prefer, 48inch or 24inch?
3. Which config would be good for better performace? circular/hexagonal and which would be easy to make?
4. Should there be a hole in middle?
5. What to use for parachute line?
6. Should I use some special kind of thread for sewing or ordinary polyester sewing thread? Can I do it on a normal sewing machine?

Sorry for so many questions. If you can please share a guide which you guys followed on how to build a parachute. Thanks everyone!

 

[Voyager1]

You should search the forum for threads discussing making your own parachutes. These will most likely be found in the Recovery section.

Have you simulated your design in OpenRocket, RockSim, or any other software? A simulation of the design will allow you to optimise your choice of parachute size and CoD (coefficient of drag) to give you a landing speed of, say, 5-7 m/s.

Designing the parachute with, say, 6-8 separate shaped panels stitched together will allow you to improve the CoD by providing a more efficient open chute profile.

 

[teepot]

My 2 cents. If it's light weight nylon and rip stop it should be ok. For a 4.5lb/72 ounce rocket I would use a 70" or 80" regular flat circular chute. A higher CD chute would be smaller. I use Rocketman 2'2 CD chutes and would use one of their 48" chutes for that weight. If you use a spill hole the chute would have to be bigger if it was circular. The 2'2 CD chute has a spill hole. For shroud lines I would use Kevlar and for sowing I would use Kevlar thread. But rather than do all of that I would buy a high performance chute from a company that makes them. Rocketman, Fruity Chutes, Spherachutes come to mind. There are others. As was mentioned above a simulation would tell you what you need to know. A thread search would go a long way to finding your answers too. Again, just my 2 cents.

 

[lr64]

If you want your rocket to come down at 25 feet per second, and your chute has a Cd of 1, you would want a chute that's 3 feet in diameter when deployed. You'll need more fabric than that, obviously. I'm assuming you launch near sea level. In the Denver area, you'd probably need a little more. The velocity is proportional to the square root of the projected area loading, if you keep the shape the same, though the kinetic energy should be proportional to the loading. The speed will be inversely proportional to the square root of the Cd. So if you had a highly improbable Cd of 2 instead of 1, you could get by with about a 25 inch chute.

I'm sure you can find a chute design someplace to copy.