Drogue Shute L3

[AmericanRocketeer]

Greetings fellow rocketeers....

I am currently building a HV ARCAS full scale duel deployment carbon fiber rocket. After propellant burn my rocket will weigh no more then 28 lbs. I have decided to use a Top Flight 96" 20-32 lb main chute. My question is what type of drogue chute should I use. I will be launching this at Black Rock with an Open Rocket simulation estimate of 18,500 ft. altitude. It gets windy on the playa and I am concerned about drift. I am going to deploy the main chute at about 1,500 ft. I am concerned if I use too small of a drogue chute when the main chute opens I will zipper the rocket or shred the parachute. I am currently considering an 18" Fruity Chute. Any thoughts or advice I would appreciate it.

 

[Bat-mite]

18" seems a little small, to me. I'd go with a 24" or 30".

 

[AmericanRocketeer]

18" seems a little small, to me. I'd go with a 24" or 30".

Okay sounds good. Have you heard anything about PUBLIC MISSILE nylon chutes. They have a center spill hole so the rocket falls straight down?

 

[tim cubbedge]

My L3 weighs about the same with no motor & I'm using a Sperachute 30" drogue with spill hole. I've heard the same about low drift with spill holes but can't confirm.

https://spherachutes.com/items/drogues/30-in-hd-detail.htm

 

[ozwald]

I have used PML chutes for all of my Cert flights including the drogue for my 70 pound Nike Smoke. I use a 36" for the drogue on the Smoke and use an 18" for my 3" and 4" models. They are very rugged IMO and have no apparent damage that I can see after many flights.

 

[AmericanRocketeer]

My L3 weighs about the same with no motor & I'm using a Sperachute 30" drogue with spill hole. I've heard the same about low drift with spill holes but can't confirm.

https://spherachutes.com/items/drogues/30-in-hd-detail.htm

Awesome info Tim. Thank you

 

[markkoelsch]

I think the 18" is probably a little small, but not by much. If you are already going with Top Flight have you considered a small Crossfire chute for a drogue?

I would not think anything larger than a 2' chute though.

 

[AmericanRocketeer]

I think the 18" is probably a little small, but not by much. If you are already going with Top Flight have you considered a small Crossfire chute for a drogue?

I would not think anything larger than a 2' chute though.

good looking out Mark... I will look into it....thanks... thanks to everyone that has helped me....

 

[markjos]

Well, if you're already running simulations with OpenRocket, how about running some with various parachutes, export the data and look at vertical velocities and drift distances? Model the 'chutes as closely as you can (or choose from the database), and see what comes up. I know, there are many variables to a parachute design, and sometimes it's tough to determine just what to use, but many manufacturers do specify Cd, or descent rate tables for various weights. If you find a drogue that gets you in the neighborhood of a 90fps descent rate, I bet you'll be good to go. Try doing the math (or at least let OpenRocket do the math). You might find that the process builds your confidence in backing up your own answers with data.

And yes, garbage in, garbage out - if you use bad information, the results aren't useful, but I maintain that the exercise is worthwhile.

You might also find that this Apogee newsletter article is useful.

Good luck with your flight.

Mark

 

[AmericanRocketeer]

Well, if you're already running simulations with OpenRocket, how about running some with various parachutes, export the data and look at vertical velocities and drift distances? Model the 'chutes as closely as you can (or choose from the database), and see what comes up. I know, there are many variables to a parachute design, and sometimes it's tough to determine just what to use, but many manufacturers do specify Cd, or descent rate tables for various weights. If you find a drogue that gets you in the neighborhood of a 90fps descent rate, I bet you'll be good to go. Try doing the math (or at least let OpenRocket do the math). You might find that the process builds your confidence in backing up your own answers with data.

And yes, garbage in, garbage out - if you use bad information, the results aren't useful, but I maintain that the exercise is worthwhile.



You might also find that this Apogee newsletter article is useful.

Good luck with your flight.

Mark

Sounds good.... I did not know you can export the data.....

 

[AdAstraPerAspera]

Okay sounds good. Have you heard anything about PUBLIC MISSILE nylon chutes. They have a center spill hole so the rocket falls straight down?

I've had good luck with PML chutes. The hole eliminates that that wobble back and forth that some chutes get, and may alter the decent rate, but the rocket will basically move with the wind on almost any chute. Check decent rates and go by that when sizing your chute.

 

[AmericanRocketeer]

I've had good luck with PML chutes. The hole eliminates that that wobble back and forth that some chutes get, and may alter the decent rate, but the rocket will basically move with the wind on almost any chute. Check decent rates and go by that when sizing your chute.

Will do AdAstra.... I am thinking I am going to use a 24" PML Dura Chute for my Drogue and a 96' Top Flight chute for my main. Thank you...