Why use a drogue

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Budro0

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So, I know why I use drogues in a dual deploy setup, but I'm curious if there is a right answer. Or a best answer.

In reading other people's posts here, I've come across a couple different reasons for using a drogue (and some for not using one).

1. Balance the drag of the separated rocket into a flat or inverted V - allows the main to be deployed away from the rest of the rocket and prevents entanglement.
2. Slow the separated rocket to allow for safe deployment of the main.
3. Something else?

I'm a "balance the drag" kind of guy, but I'd like to see if there is some consensus among the crowd on the best answer.
 

OverTheTop

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Personally I am a (2) sort of guy. Bring the rocket down fast but in a controlled manner. I am not personally concerned about having it come in flat or inverted-v. YMMV :).
 

Wayco

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Personally I am a (2) sort of guy. Bring the rocket down fast but in a controlled manner. I am not personally concerned about having it come in flat or inverted-v. YMMV :).
You live in Australia, everything is inverted.
I'm switching out my small drogue chutes to Top Flight streamers, based on the decent rate I'm getting off the RRC-3 altimeter. Looking to get them down faster, and they are more visible.
 

Antares JS

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#1 for larger rockets. Another reason: Visibility. On even small rockets that don't have/need drogues, I attach a streamer to the drogue harness to aid visibility.
 

DAllen

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Drogues break up the stability of the falling parts. Had a buddy almost fail his L3 because he went drogueless. The upper part with the main was quite nose heavy and started to come down first dragging the fin can along much like a lawn dart. Main deployment happened at a real high velocity and to be blunt I was shocked there was no damage. No idea who is TAP was but as I recall this happened in '07.
 

Buckeye

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I'm switching out my small drogue chutes to Top Flight streamers, based on the decent rate I'm getting off the RRC-3 altimeter. Looking to get them down faster, and they are more visible.
This^

Streamers will fall faster than drogueless and drogue chutes, yet remain in a kinda organized, vertical, orientation.
 

Budro0

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It can also be used to pull a d-bag out and ensure proper inflation of a larger chute
Valid point, but would that not make it a pilot chute? Or do you use the drogue to slow descent/orient the airframe, and also as a pilot for a d-bag?
 

Budro0

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This^

Streamers will fall faster than drogueless and drogue chutes, yet remain in a kinda organized, vertical, orientation.
So do you like your descent to be oriented more vertically? I like a fairly flat fall
 

Budro0

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Drogues break up the stability of the falling parts. Had a buddy almost fail his L3 because he went drogueless. The upper part with the main was quite nose heavy and started to come down first dragging the fin can along much like a lawn dart. Main deployment happened at a real high velocity and to be blunt I was shocked there was no damage. No idea who is TAP was but as I recall this happened in '07.
This is my main concern - orient the airframe in a way to maximize the drag of the airframe itself, so it doesn't burn in.
 

Buckeye

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So do you like your descent to be oriented more vertically? I like a fairly flat fall
I like my descent to be fast (hence more vertical) and visible. So, streamer for me. I fly plenty of high-altitude shots, and rockets with drogue chutes or no drogue at all can drift a long way before the main is deployed. I have not run into any problems with the main shredding while deploying. Yet.
 

Budro0

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I like my descent to be fast (hence more vertical) and visible. So, streamer for me. I fly plenty of high-altitude shots, and rockets with drogue chutes or no drogue at all can drift a long way before the main is deployed. I have not run into any problems with the main shredding while deploying. Yet.
That's fair. I'm not sure I've ever flown over 5k. What are your speeds like at main opening and do you use "heavy duty" chutes to account for it?
 

ep29030

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You don't need a drogue for most rockets. I would argue the main purpose of a drogue is to orient parts of the rocket to assure orderly (safe) deployment of main parachute(s).
 

MJW

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Personally I use them to create an inverted V for organized main deployment. My main usually uses a reefing ring so deployment velocity is not a big concern as long as the rocket is in two pieces when it deploys.
 

Budro0

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You don't need a drogue for most rockets. I would argue the main purpose of a drogue is to orient parts of the rocket to assure orderly (safe) deployment of main parachute(s).
I mostly agree with you. When it comes to dual deploy rockets, I do all the calcs to figure how big a drogue I'll need, but I still watch carefully on the first couple flights to fine tune it. In the end, I usually size down a bit to balance. In my experience, some rockets don't need drogues.
 

Buckeye

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That's fair. I'm not sure I've ever flown over 5k. What are your speeds like at main opening and do you use "heavy duty" chutes to account for it?
I had a couple flights around 80-90 ft/s average at main deployment. I am a total cheapskate when it comes to parachutes. Nothing heavy duty.
 

Budro0

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I had a couple flights around 80-90 ft/s average at main deployment. I am a total cheapskate when it comes to parachutes. Nothing heavy duty.
I feel like 80-90fps is still manageable for most chutes. Off the top of my head, it seems like my L1 bird was up around 80fps at main opening with no issues. Still, in my mind, it seems like having a more vertical orientation would lead to higher speeds and a larger opening shock.

Do you have video of your flights? I'm curious to see how your rockets orient under a streamer.
 

Mike Haberer

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Drogues break up the stability of the falling parts. Had a buddy almost fail his L3 because he went drogueless. The upper part with the main was quite nose heavy and started to come down first dragging the fin can along much like a lawn dart. Main deployment happened at a real high velocity and to be blunt I was shocked there was no damage. No idea who is TAP was but as I recall this happened in '07.
Drogue less only works well if the two parts of the rocket are about the same weight and with a sizeable cross section (aka, big bird). Heavy nose cones are killers. Heavy fins cans aren't much better.
 

Budro0

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Drogue less only works well if the two parts of the rocket are about the same weight and with a sizeable cross section (aka, big bird). Heavy nose cones are killers. Heavy fins cans aren't much better.
I know what you mean. I had a single break rocket that I flew with a JLCR. I did have a fair amount of nose ballast but still figured I'd put a little drogue on it the balance. Problem was, the drogue lined everything up and the rocket would slip laterally with the fins pointing the way. I figured out pretty quick to just use that one drogueless and never had any wild descents after.
 

Rob Campbell

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The purpose of the drogue is to allow the rocket to descend rapidly enough so it doesn't drift too far from the launch site, yet slow enough the main will deploy without damaging either itself or the rocket.
 

Onebadhawk

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I will never fly without a drogue..

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