Min-Diameter Electronic Recovery

What's the smallest diameter that you ever used electronics for recovery? I saw that Perfectflite has a pretty tiny altimeter with events. Just curious how small a rocket you guys have actually done it with.

Kruegon said:

What's the smallest diameter that you ever used electronics for recovery? I saw that Perfectflite has a pretty tiny altimeter with events. Just curious how small a rocket you guys have actually done it with.

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I'm working on 38mm, bit that's still relatively large. I know someone on here's doing 18mm. I think that's about as small as you can really go.

Nate

My smallest was a scratch built with 2.0" ID BT. The inside of the av-bay was about 1 7/8" I used a HiAlt45 with 9v battery and a pair of 1/4-20 threaded rod. It was my first av-bay and my L1 cert rocket. I learned a LOT building that. My advice is that if you want to try a small diameter, go for it. It may not turn out perfect, but you'll learn a lot by doing it and the next one will certainly be awesome.

maxvelocity just did an 18mm md with electronics.

I was only curious because I thought it might be better to learn on a 20.00 rocket in case it crashes. My L1 cert is coming up this fall (flight season is over for the local HPR group) and I'm planning to use DD for better recovery.

I have used a Telemini in a 24mm MD. Dual deploy with radio directional tracking.
Greg

I'm working on a 10.5mm airframe with electronic deployment. Timer based with a PicoTimer.

Kruegon said:

I was only curious because I thought it might be better to learn on a 20.00 rocket in case it crashes. My L1 cert is coming up this fall (flight season is over for the local HPR group) and I'm planning to use DD for better recovery.

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Good plan. Get an Estes rocket that will handle a 24mm motor so you can fly it on C-F motors. The Orange Crush is a good candidate for hacking into DD and it's got a BT60 body tube so there's plenty of room for any altimeter and battery that you may want to use.

What electronics do people use in an 18mm minimum?

Hmm odd thought. Can you do DD without L1?

Kruegon said:

Hmm odd thought. Can you do DD without L1?

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Yes

Kruegon said:

Hmm odd thought. Can you do DD without L1?

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Yup. I'm planning to do a DD flight or 2 at our next launch that wouldn't require L1. A 1.7lb rocket and a G64

Nate

cwbullet said:

What electronics do people use in an 18mm minimum?

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Mainly Altimeter One/Two/Three's from what I've seen. I haven't personally seen any 18mm DD's, but I suppose if you had an old Astron Farside or the like you might think about it...

I'm currently working on a 29mm MD with DD. It's a tight fit but it should work.

Kruegon said:

Hmm odd thought. Can you do DD without L1?

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At the PMW field, it almost doesn't make sense to do dual deploy with Level 1. Just angle the rail slightly towards the railroad tracks and you're nearly guaranteed to land in the field. (Well, for Level 1 on a decent day, at least... I'd say most L1 cert flights do 2000-3000 ft, which is pretty low for our recovery zone.) Dual deploy adds a bonus layer of opportunities for things to go wrong. In fact, I think the only time you *have* to do DD is just before L3.

In my case 38mm is the smallest I have done. This was largely due to the size of the altimeters I had. Things used to be larger than the current crop of tiny electronics. I am thinking about a 24mm for use with the CTI 24 mm motors- really cool little motors.

The smallest DD I've done flew on a K (we had a BIG flat field at the time). Done many SD with 29mm and 38mm though (E and above).

Micro DD's are a challenge due to the small space for the devices. The Pico AD4 is quite small but not necessarily that easy to use. https://www.picoalt.com/ I wouldn't do it for an L1 and would do motor ejection for an L2. After that, would do DD's with
H, I's and J's to gain experience before tackling an L. Kurt

Kruegon said:

What's the smallest diameter that you ever used electronics for recovery? I saw that Perfectflite has a pretty tiny altimeter with events. Just curious how small a rocket you guys have actually done it with.

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I've been flying rockets with 18mm electronics and 4 channels for a couple of years. These are home-made altimeters.
I'm about 80% done with the Estes Elliptic II 2-stage rocket that uses BT-20 tubes. It will probably have it's maiden flight this year at NSL.

Here an example with the altimeter controlling stage ignition, apogee ejection and main ejection with an Estes Mongoose:

[YOUTUBE]DdArnh-bf58[/YOUTUBE]

and here using the same 18mm altimeter and functions on an Estes Ascender:

[YOUTUBE]6CCZ3QzfRmg[/YOUTUBE]

jmattingly13 said:

Dual deploy adds a bonus layer of opportunities for things to go wrong. In fact, I think the only time you *have* to do DD is just before L3.

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Dual deploy adds a bonus layer of fun and new skills. I do it on every flight because I think it is cool. I mastered DD with midpower well before doing L1 and L2 (also with DD) . DD and Level 1 and 2 are not related at all. Why do so many people want to make this connection?

Rocketry is a hobby. Do it as you please. I look at my L1 and L2 certifications not as stand alone accomplishments, but as necessary evils to reach flight objectives, like more altitude.

Buckeye said:

Dual deploy adds a bonus layer of fun and new skills. I do it on every flight because I think it is cool. I mastered DD with midpower well before doing L1 and L2 (also with DD) . DD and Level 1 and 2 are not related at all. Why do so many people want to make this connection?

Rocketry is a hobby. Do it as you please. I look at my L1 and L2 certifications not as stand alone accomplishments, but as necessary evils to reach flight objectives, like more altitude.

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I couldn't agree more Buckeye, well said. There seem to be two camps on this topic, slow/low/get it done/move on, and those of us who want to go above and beyond taking unnecessary risks but having fun along the way.

As I am yet to get my L1, this is strictly conjecture.

The mastering of any skill is two fold. The learning and the implementation. Studying the requirements and mastering the understanding of the information is a crucial step in any endeavor. In this one, all the construction skills gained through years prepares us for building our a/v bay. Understanding the altimeter properly is a matter of study.

Assuming that all this is accomplished, the implementation seems a simple thing.

I am actually considering accomplishing 4 of my 5 year end goals in one motion. L1 cert. Dial deploy. Break Mach 1. Break 1 mile.

Is it wise to try such? Probably not. But think of the accomplishment if I do. But again, I'm considering it.

One other thing to keep in mind here (just pointing it out), you're not the only one affected by your cert attempt(s). At least with TRA it also takes the Prefect's time to observe your flight, and in the case of an L2 administer the test, plus any paperwork to fill out (I think they have to fill out paperwork even if you fail). I feel more terrible about the fact that I've wasted my Prefect's time administering my the test twice (first time I got 44/50 due to not really being prepared, second time I passed the test but then the rocket face-planted) than my personal loss in the destruction of my rocket. So the net effect of a failure to certify isn't purely your own time & effort, it wastes other people's time as well, and for Tripoli at least as I understand it it's generally the only person who can do certs at a local launch, so that potentially affects other people's ability to cert at the same event (the more time they have to spend on you the less time they have to help others). So I'd say a lower-risk cert attempt is more courteous to others as well, not just an increased likelihood of success.

Kruegon said:

As I am yet to get my L1, this is strictly conjecture.

The mastering of any skill is two fold. The learning and the implementation. Studying the requirements and mastering the understanding of the information is a crucial step in any endeavor. In this one, all the construction skills gained through years prepares us for building our a/v bay. Understanding the altimeter properly is a matter of study.

Assuming that all this is accomplished, the implementation seems a simple thing.

I am actually considering accomplishing 4 of my 5 year end goals in one motion. L1 cert. Dial deploy. Break Mach 1. Break 1 mile.

Is it wise to try such? Probably not. But think of the accomplishment if I do. But again, I'm considering it.

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I think if you want to do all those things for your cert attempt, you should. Go For It!

It is your hobby and you should get out of it what you want. Enjoy.

I didn't really think about the mile high and mach for my cert, but I did almost the same thing for my L1. My goal was to learn as much as I could about HPR construction and dual deployment so I scratch built a DD rocket and flew the cert on a I110 Loki moonburner that got 4,200 ft. If I had thought about the mile high and mach for a cert, I might have tried the AT I600R instead. I met my goals for my L1 and if those are your goals for your L1, pursue them! That is what makes the hobby fun for you!

You certainly can do 4 new things on a L1 cert flight, but why would you want to put that kind of pressure on yourself.

The only requirement to get a L1 is to build, launch and successfully recover with active recovery a rocket containing a H or I impulse motor.

Electronic deployment is only required for L3 certifications, but electronic recovery has been accomplished in 13 mm airframes, Mach flights have been conducted with High Power F and G motors in 24 mm airframes, and mile high apogee flights have been obtained with 2 stage F impulse model rocket motor.

You could easily build a more conventional 38 mm rocket that you could learn to do dual deployment flights with G motors with a 1000' apogee, do a L1 cert flight with a low H impulse motor at a 1500'-2000' apogee, and then use a fast burn and/or a full I motor to break Mach 1 and/or a mile apogee.

The advantage of this approach is that your rocket can do it all, but you don't have to do it all in a cert flight. We used incremental goals to put men on the moon: Mercury Redstone put a man in space and recovered him safely; Mercury Atlas put a man into orbit and recovered him safely; Gemini Titan put 2 men in space and recovered them safely, and proved rendezvous and docking in space could be accomplished; Apollo Saturn 1 put 3 men in space, and proved rendezvous and docking with a LEM; and Apollo Saturn 5 went to the moon and back and then landed and successfully returned men from the moon's surface. Yes we could have attempted to go to the moon in one step, but it is likely there would most likely have been serious failures with in-flight loss of life along the way.

My 2 cents.

Bob