Dual deployment & gadgets and stuff

After Whitakers and viewing all that spensive stuff and parachutes and socks and hats and coats and any sort of things people had flying out of their rockets, well I have a question.
What would be the cheapest (not junk), smallest (size of rocket) and electronic parts that I would need to do a dual deployment?
Remember, this is coming from a guy that considered Aerotech F and G as big motors until this past weekend.
Thanks for any help.
Randy

Good question airforce! I think you could do a dual deploy using a G-Wiz, an E30, and maybe BT-50 (assuming a standard 9V battery would fit).

You could probably go way smaller if you used like a MAD to pop the drogue and one of those teeny timers for the main. Think this could fit in a BT-20 (?). A D21 might boost it well.

Your forgetting the rocket pants...

Mark Brown did the most research on this subject trying to get the best bang for his buck. I will get him to chime in here. One of the ones that he ended up with is the G-Wiz.

Now, to save you some time and money, (reading between the lines) I like to offer this set of guidelines for certification:
For level 1: Single deploy - low and slow.
For level 2: Dual deploy - one altimeter - low and slow.
For level 3: Dual deploy - two altimeters - as low and slow as possible.

So, if you are thinking about level 1, I would suggest a simple H level rocket. PML sells a Pterydactl, Jr that would be perfect. Low and slow...

Oh, and check out this document:

https://secure.consumersinterest.com/pml/home/images/pmlalti.pdf

It shows the estimated height by kit/given motor. This may help you make a decision. The Tethys looks good too.

LOL... I have sorta changed the subject on ya havent I?

Ooops, I misinterpreted the thrust of this thread (?)

The G-Wiz is nice because it has 3 channels: drogue at apogee, main at either 400 or 800 feet (factory set), and also has a channel for either launch detect or booster burn-out (configurable). IIRC it is the only unit in that price range that does all three. At least it was at the time I bought mine. I have used all these functions (but not at the same time). What it doesn't have is an audible 'readout' of altitude, or a PC interface. There is now a G-Wiz flight computer, but I don't know much about it.

Here are my personnal recommendations:

L1 - motor ejection only (low to medium performance)
L2 - single deploy (low and slow)
L3 - listen to the L3

On my L2 I planned it to use electronics and motor ejection as a backup. I have heard people say this is a bad thing. However, I can't say I bought into their rationale.

Thanks guys.
I wasn't really referring to any level requirements but I really do appreciate your information. I'm just saying, for example, could you take an Estes Executioner and make it dual deploy? how'd I do this time?
I'm doing a scan for G-Wiz right now.

Randy
ps. I am giving great thought concerning the L1, why not!!!!

So I had it right the first time, eh

The G-Wiz can be found at Pratt Hobbies or Aerocon. If you get one you might want to sign up for the GWiz Yahoo group. The designer monitors the group, as well as Doug Pratt.

FYI: My level 2 was done with an altimeter as main and motor ejection as backup. It all worked fine except I had blowby from the motor ejection which reached the altimeter which fried after it did its job. So, it isn't impossible, you need to make sure the airchamber of the altimeter is sealed tightly.

GO AIRFORCE! GO AIRFORCE! GETCHA LEVEL 1!

On my L2, the motor eject happened several seconds after the apogee charge. Not optimal by itself, but hopefully would save the rocket. As it turned out it wasn't needed, an I doubt if I'd ever fly it on that small a motor again.

I agree with Phil. If you buy an altimeter, you might as well go for L1. If you want, get a bird that will fly on a small/mid H and G's. That's also what I did so I'm biased

I'm planning on certing L1 with motor ejection only, so as to make it as simple as possible (Small Endeavour, torn between using an H238 and an H165. Both just over 2,000 feet, so should be a good flight without having to strain the eyes to see it). After that, I'll start looking into DD with an altimeter and a Phobos (most likely). Sound good, or does anyone have better suggestions? I like PML just because if something happens and I screw something up, I'm more likely to recover with minimal damage and be able to try again...

Loopy

Randy,
I've done some research but, not quite the level that Phil leads you to believe. I like the G-Wiz but, it's not the cheapest unit out there. I've got a Missile Works RRC²X unit and it is really nice for $95. I've also heard good things about the PerfectFlite altimeters for about the same price. Both of those are really compact and are among the smallest altimeters. Regardless of which altimeter you choose, you'll have to design an altimeter bay for it. This can be challenging in smaller rockets. I hear mshaner is the expert in this area. Hope this helps.

Originally posted by Loopy
I'm planning on certing L1 with motor ejection only, so as to make it as simple as possible (Small Endeavour, torn between using an H238 and an H165. Both just over 2,000 feet, so should be a good flight without having to strain the eyes to see it).

Click to expand...

Loopy,
I've used both motors before. I certified level one using an H165. It is a really sweet motor. If you like redlines and you can find one, that'd be my recommendation. I just love the red flame!

airforce:
I am beta-testing a picoalt ad2
https://www.geocities.com/rdh82000/Picoalt/index.htm

3gr w/o battery
also supports cdi: capacitor discharge ignition

shockie B)

Thanks guys for the info, keep it coming, if there is anymore.
Sorta sounds like I might as well forget my small rocket idea, I really liked the idea of using the 2 chutes or a streamer and a chute to get that baby to come back closer to where it departed.

Phil, thanks for the cheer, you wasn't on top of your desk when you did that were you?

Shockwave, that looks cool and small. Please let me know how your testing goes.
Thanks

I was on the top of my desk... But what really got me in trouble is when I took off my shirt and started swinging it around my head...

Swinging what around your head????
Are you braging? Oh! you mean your L3 cert???

I still can't get the picture of that beeutiful rocket of yours taking to the sky, what a launch. I just finished going through all 90 pics that Carl put up and there it was again.

Amraam, what more can you say about that big hulk, I love pics.
I think those of us that made it there finally got to realize some dreams. My wife asked me if I liked it and would I go back, now this was just after getting home from 9 hours of driving. I said,
"I would leave tomorrow morning and make the same trip".

I wasn't even considering the meet that's going to take place somewhere in Penn but now I'm not sure, I just might check the dates and my money sack, you never know.

Something else my wife said, she said, you need to get one of those altimeter things, that sounds neat, someone stop me!!!

OMG!!!!

A man with permission!! Look out!!!!

Sorry you never got to find your legacy Airforce, that was a cool flight. I was thinking that putting a G in a Legacy was something Phil would do, then I remembered that he did put an F into an Estes Super Shot.

Hehehe...you won't find any one here to stop you! All you'll get here is encouragement

PLUS, one the boss encourages you, you best get with it

Heres a suggestion from your uncle Phil. Now that you have permission (which is the big hurdle) now you have to find that medium. Lets see, $100 for an altimeter = $20 as far as the wife knows. $150 level 1 kit = $50 as far as the wife knows. etc...

I think I need to bleach my eyes after the visual of Phil on his desk with his shirt off swinging it around his head.

I used a Perfectflite MAWD on my unsuccessful L2 flight. At $99.95, it's among the cheapest of the altimeters and it has a capacitor to help make sure you have enough juice going to the ematches for deployment. For an additional 15 bucks, you can buy a cord and software that lets you download data to your PC. I haven't done this yet, so I don't know how useful it is, but it's a neat gadget!

Anyway, despite the nasty wrenching the sheard fins put the rocket through, the altimeter performed flawlessly. I wouldn't hesitate to get another one should the need arise and while I have never used another to make a comparison to, I would recommend this one to anyone.

Does it have user selectable main output altitude? If so, what are the ranges? I'm interested in this altimeter, and have heard good things about it, but I want to be able to select different altitudes for main deployment...tends to get kinda windy here in the midwest!!!!! lol

Loopy

Loopy,
Do a Web search using Perfectflite and read all about it.
Thanks Kermie and the rest of you guys for all the information.
Randy

Airforce,

I've used the PerfectFlite MAWD altimeter and MissileWorks RRC2 altimeters and have had nothing but success with both. The MAWD is DANG small and could be used in an Executioner if you wanted to, plus its got great features for the price.

I am a total convert to dual deployment after about a year of flying that way. For me, DD is at least as reliable as motor ejection (I recommend plugged fwd closures - blow-by is BAAAAAD!), and it is COOL. Nothing sweeter than BIG altitude and dropping the rocket within an easy walk of the pads.

In my mind, the biggest problem with using altimeters in small rockets is having enough space to get all the wires and stuff in where you want them. If you could build a 2.5" or 3" rocket that is light enough to fly on the smaller engines you like to fly, I think it would be an easier first try than trying to do it on a skinny rocket. You eliminate the need to worry so much about space restrictions.

--Lance.

Loopy,

Yes, it has user selectable main...anywhere from 300' to 1500' I believe (if you go 300', you're a braver man than I). I picked it up because of the features for the price, but llickteig is right...it's very small as well.

Thanks llickteig1 for your input.
This is exactly what I was hoping for and didn't doubt for a minute that I would get this great feedback.
Now I'm really getting excited. Must have ALT, must have!!

Thanks to you all.
Randy

Hey Shock, I can't find an email address for you, so I can't keep bugging you about your test using the picoalt ad2 that you mentioned earlier. Please let me know your results.
Thanks
Randy

Originally posted by KermieD
Loopy,

Yes, it has user selectable main...anywhere from 300' to 1500' I believe (if you go 300', you're a braver man than I). I picked it up because of the features for the price, but llickteig is right...it's very small as well.

Click to expand...

What is the "general" difference in main deployment altitude and acttual chute fully open altitude?

IE, if you set the main for 500 ft at what altitude could you expect it to be fully open? Of course I realize there would be many varibles.

Like you said there are a lot of variables, I doubt if there is a pat answer. Chute size alone is a big factor...then there's rocket weight, packing/folding, speed when it is ejected.....

...length of shock cord....