When do you Dual Deploy?

I jumped on the dual deploy band wagon with both feet a few years ago, not that I regret the decision to build all of my rockets capable for DD, I find that I do a DD set up less and less. Our field is big enough and our waver is only 10k, most rockets I fly only do 4k to 5k mostly under, even my J flights stay under this.

While i'm a firm believer of a backup apogee ejection, that's all i'm finding that i'm doing. Save the money and extra set up time I guess if i'm going to keep it under 4k. I just haven't had to walk that far to get my rockets yet at this level of flight.

At what point do you all bag the dual deploy and just do a down and dirty basic recovery? Sure a lot of factors come to play, altitude and size of field as the main ones. As cool as it is I'm just not finding it necessary as much any more, I guess till I get some flights over 4k.

All that said I think every HPR rocket should have a backup apogee eject, and should have the ability for DD for that day you stuff the biggest baddest motor in.


TA

I always do an altimeter deployment when possible. No having to adjust delays.

Not to mention I get more practice doing DD.

blackbrandt said:

I always do an altimeter deployment when possible. No having to adjust delays.

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Do you find that setting up the altimeter and BP charge is less work than drilling a delay? Which do you think is less prone to human error?

Both of the HPR fields I fly at have their challenges. One is on a hilly ranch, the other is on a farm surrounded by canals, corn, wheat, etc. They can both be fairly windy too. I'd say 2000' is the hard limit for me. Even then we've had some epic hikes at the ranch. Anything over that and it's going DD.

Even if you have a big field and don't mind walking 300 yds. to your rocket, I still think it is fun to try to land as close to the launch area as possible (of course, staying away from the spectator area).

Well, the way I look at it, I get the enjoyment of altitude reports after the flight, the practice of setting up an avionics bay and charges, and a feeling of accomplishment. It may not be less work, but it is almost always more accurate than guesstimating a delay. Just throw the altim in there and go launch.

CZ Brat said:

Do you find that setting up the altimeter and BP charge is less work than drilling a delay? Which do you think is less prone to human error?

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+1 with Chris. I don't mind setting up DD for flights over 2 grand. I have even been setting up more and more of my single break rockets with altimeters in the nose cone and cable cutter deployment. I get a lot of satisfaction from watching DD deployments.

I agree with Jim. I went several years not flying rockets that required a delay and when I went back to it I remembered what a pain in the butt it was to figure out what the delay should be. I'll take a flight computer every time.

Andrew

I prefer electronic deployment as well...
I wouldn't even go to 2K and deploy a main....
I'm tired of those epic recovery's.... lol
And I agree with,, there is a sense of satisfaction from a successful dual deployment....

Teddy

I hear what you are saying TA. I actually prefer motor eject over DD because I like the simplicity. I have gotten away from DD for the most part. Not to say I am opposed but for most of the flying I do I prefer the simply goodness of motor deploy at apogee. We seem to fly the same type of rockets to the same altitudes although if I had your waiver I'd be going higher. A Magg to about 2500-3k on motor deploy is just too fun, no need to bog it down with DD.

All of the rockets I fly anymore ar DD. I don't have to worry as much about winds aloft and the recovery is closer. The time savings of apogee deployed rockets may be off set by the added walk time.

Well I do like the safety of a backup eject, I run my motor eject a second or two long and let the electronics fire at apogee. The last two failures I have had do to some problem with the laundry not deploying, the rockets have been saved and only slightly damaged do to the fact the rocket was a least separated. (no ballistic reentry)

I let the electronics do the work and the motor is the backup. Most of my AV bays have redundant electronics all the way down to 3" dia rockets.

Its just the under 4k DD is a waste of money and time at our field. It's still fun to see it work and I may lower my ceiling if I find i'm walking to far.




TA

I just started dual deploy this year. After many long walks even on sub 3k flights...I've started building all my rockets to use it. At least for now I cannot see flying without it.

BalDave2 said:

All of the rockets I fly anymore ar DD. I don't have to worry as much about winds aloft and the recovery is closer. The time savings of apogee deployed rockets may be off set by the added walk time.

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+1 for sure...

Teddy

It's all very well to figure out what the delay should be but if the flight does not go as expected then electronic deployment is a lot more likely to bring your rocket back undamaged.

Always... unless you like walking or you fly in "no wind" conditions.
Back to the OP's question however, perhaps you should clarify... there's discussion on electronic deployment vs. motor based deployment instead of single-event or dual-event recovery?

Ya this is just about dual event recovery, I did touch on a back up at ejection is why it may have gone that way a bit.

All my DD are single separation cable cutter so the matter of no DD is just omit the cutter, no moving the parachute around.


TA

I'm also wondering about dual deploy... I'm planning on building my first real HP rocket this winter, and I'm wondering about the added construction and electronics cost vs benefit ratio.

In my book, there is a lot to be said for simple motor deloyment. Much faster flight prep and apart from issues on my part, very reliable.

For the fields I fly, I would consider 1500'-2500' to be the altitude limit for motor deployment. Above that, or in high winds, then it is DD

I fly DD whenever I can squeeze it into a rocket; even electronic single deploy when possible. I've had more recovery issues with motor deploy than electronic. As others noted, with the main at 500' or so, it cuts down on drift if its windy. Also, most of my motors are EX, and though I can use Loki delay grains, I don't want to depend on them and unproven timing. In 38's, I sometimes put in an undrilled Loki delay to use as a just-in-case late backup, never actually needed it though.

I also use full delay for tracking smoke. It burns after apogee, so I get even more tracking.

CzTeacherMan said:

I'm also wondering about dual deploy... I'm planning on building my first real HP rocket this winter, and I'm wondering about the added construction and electronics cost vs benefit ratio.

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The benefits are pretty well spelled out throughout this thread, you can fly higher and recover closer as well as increased deployment reliability. Costs really depend on your building materials, but all you need is an additional section of airframe (length is typically a personal preference) and a coupler with bulkheads. You will need to make a mounting sled for your electronics and batteries. I like to use an arming switch but many people prefer the hard wiring method. Also, you will need an altimeter or 2. There are many different brands and models to choose from which can be had for around $40 per altimeter and up depending on the features you want.

Anything much over 2,000-2,500', when feasible. I'm not going to go retrofitting any existing rockets we have that MAY see 2,000' on a good day, but if I expect a nominal flight on a particular rocket to be in the 2,000+ range, I'll figure dual-deploy at design and will fly as such.


Later!

--Coop

I am trying to do at least one DD flight at each how power launch , whilst marching toward a Level 3 flight.

The more I do it, and in various rockets - the better I get at av-bays, preprep and getting the rocket on the pad . The biggest epiphany had lately was 'This would not be so hard, if I had more altimeters' - so grabbed a couple of eggTimers (built by CaveDuck) to supplement the RRC3 and Raven that usually ride together.

Kenny

My reasons for using DD are more geared to where I am flying than anything else. I don't mind a walk to go get a rocket as I enjoy the outdoors and it gets me exercise which I need. Having said that , it's not fun walking thru swamps, and 6 foot tall weed patches after the almost always existent winds pushes my rocket to the undesirable areas at our launch area. So for the most part anything over 2000-2500 feet I generally am thinking DD as I have a bit better control of missing some of the challenges ( or so I think).

I enjoy both aspects of launching rockets with motor deploy and DD. There are times when the simplistic motor deploy appeals to me more, especially if I have friends or relatives coming out to spectate as I find I can visit more during prep than with a DD rocket.

I think if I was launching somewhere very flat such as a playa, I would go higher with non DD flights. One day I hope to test that theory.

KenRico said:

I am trying to do at least one DD flight at each how power launch , whilst marching toward a Level 3 flight.

The more I do it, and in various rockets - the better I get at av-bays, preprep and getting the rocket on the pad . The biggest epiphany had lately was 'This would not be so hard, if I had more altimeters' - so grabbed a couple of eggTimers (built by CaveDuck) to supplement the RRC3 and Raven that usually ride together.

Kenny

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I think i'm going al-natural for my L3 it will be low and slow and only redundant backup main deploy at apogee. The motor cost to dang much to fiddle around with anything else.

Rrwjr said:

My reasons for using DD are more geared to where I am flying than anything else. I don't mind a walk to go get a rocket as I enjoy the outdoors and it gets me exercise which I need. Having said that , it's not fun walking thru swamps, and 6 foot tall weed patches after the almost always existent winds pushes my rocket to the undesirable areas at our launch area. So for the most part anything over 2000-2500 feet I generally am thinking DD as I have a bit better control of missing some of the challenges ( or so I think).

I enjoy both aspects of launching rockets with motor deploy and DD. There are times when the simplistic motor deploy appeals to me more, especially if I have friends or relatives coming out to spectate as I find I can visit more during prep than with a DD rocket.

I think if I was launching somewhere very flat such as a playa, I would go higher with non DD flights. One day I hope to test that theory.

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Oog a swamp would warrant a DD every flight.

TA

I just did level 1 cert now will try 2 with dd.