My approach to Level 1

Just thought I'd post something directly about rocketry, and a couple other
folks have described their approach to NAR Level 1. Here's my plan...
I've acquired my Skyripper H hybrid motor and most of the pieces of GSE...
I've learned a lot about some very obscure (and hard to find) gas fittings.
All the rocket pieces and materials are on order, and I finally bit the
bullet and ordered a flight computer-- I settled on the G-Wiz LC 400. I like
the accelerometer-based apogee detection, and the power output (supports two
batteries).
The rocket will be an overstable 4" x 72" (+/-) scratch built, G10 fins
(hopefully... I've gotten some tips from my cousin the machinist on cutting
and handling the stuff, and think I can pull it off. If not, plywood). Dual
deployment, ejection at apogee (drogueless -- 25' 9/16" tubular recovery
harness), a 54" x-form chute at 400'. Weight right around 5.5 lbs. If final
ground testing supports what I've found so far, I'll be introducing a
variation on main chute deployment, mostly applicable to hybrids. Of course,
none of it matters until the bird is flown and back in hand, undamaged, but
damn am I having fun planning. Complexity means failure points, and I've
always loved dancing with Murphy.
Barring the unforseen, at our Section's June launch I plan for a 1000' L1
certification flight on an H155 load, top speed of about 170mph. I took the
suggestion "low and slow" quite seriously.
Kevin OClassen
NAR 13578
Reply to
Kevin OClassen
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What size MMT are you putting in that? Sounds like it could be good for the smaller HyperTek motors too (300/440CC).
I'm taking a similar approach, similar motor, but smaller airframe and only single deployment. I'm looking at about 2000ft on a WCH H100.
I now have a head full of pipe fittings too!
I guess my approach can be summarised as 'KISS, SCHMISS'!
If I hadn't happened to win a 2.6" rocket that would take the motor, I would probably have built something a bit smaller and sleeker. Then again, with a relatively low flight using apogee-only deployment I can use my G-Wiz MC's low altitude channel in 'apogee delay' mode and fire a backup charge. I am considering a separate backup timer too, not really sure I want 3 charges though, so I may go for having the separate timer and G-Wiz channel firing the same charge via separate e-matches, if that makes sense.
Good luck, its nice to read of someone doing an interesting L1 :)
Reply to
Niall Oswald
38mm x 28"
I designed the rocket around the Skyripper H & I 38mm cases, since that was the motor I ended up with. After my certification, it should fly to about 3000' on the SR I motor.
We fly from tree-surrounded small fields, and I really want to get my cert flight back... hence the low altitude and the low main deployment.
I plan to start from scratch for L2.
I want that on a T-shirt.
Kevin OClassen NAR 13578
Reply to
Kevin OClassen
I take it the J won't fit then :( The SRS motors look nice - simple and elegant, as well as shiny as anything :) My L1 rocket was never intended for hybrids, but I made the MMT long enough for a 6-grain Pro38 with L2 in mind, and that just happened to be long enough for an H hybrid.
Ah, I guess I've been spoilt by my weekend visit to a site with massive altitude potential!
Might have to do that in time for UKRA'04, when I plan to launch my L1. I really hope it works! You will post up the results, wont you...
Reply to
Niall Oswald
That is a very nice rocket and motor to fly for your L1 Kevin !
I've flown the Skyripper H and I in a LOC Easy I-65 and it was a nice filght.
Reply to
AlMax
Kevin,
Why do you want to dual deploy from a 1000' flight? Going only to 1000', you might want to consider single deploy.
I can appreciate wanting the complexity of electronics on a cert flight, because I did my first electronics for my L2 cert. I personally would be more comfortable flying the "I" motor to 3000' and doing dual deploy. You also might want to consider boosting your second deployment altitude up a bit, maybe to 800' for your first flight. This gives a bit of extra time to "work things out" if a chute gets tangled or something. Go for the lower deployment altitude when you're sure that your 'chute packing skills are up to speed.
Those are some of my thoughts and experiences with dual deploy. However you decide to do it, good luck on your cert flight!
Reply to
J.A. Michel
Joe,
You've no idea how I've dithered about this issue. Your post recrystallized the points I've considered, and reminded me of something important. Cheaping your way out of a situation leads to problems. That's what's happened here. Cheapie me was trying to save $60 by buying the G-Wiz LC instead of the MC. Unfortunately the LC comes in *either* 400 or 800 foot main deployment only. The LC will not let you choose deployment height.
Your post pushed the final button, durn it. I called Aerocon and changed my order to a G-Wiz MC. So, LOL, the plan for my cert flight is now something like "drogueless deployment at apogee, main ejection 3 seconds later". Might end up being 800' for main deployment. Because of the way my recovery system is set up, I have to use dual deployment, but the MC gives me the flex to take the most reliable route.
Sempre Gumby!!
Kevin OClassen NAR 13578
Reply to
Kevin OClassen
The MC has a bunch of useful features - not only the datalogging but you can use the main channel as a post apogee timer, which I am planning to do on my L1. Its also got the handy safety jack - you did order the 'remove before flight' tag, right :)
It sounds like it will be a fun cert flight - doing it in style! If I make that t-shirt, it will have 'The more failure modes the merrier' on the back I think :)
Reply to
Niall Oswald
I know that saucers are approved for L1 cert flights, but I would personally be far more impressed with someone who pulled off a flight like the one Kevin is planning (or dare I say the one I am planning) than flying a saucer. That said someone might have been flying dual-deployment minimum diameter rockets on G80's (or even better G hybrids) and just wanted a simple cert flight to move onto H's.
Of course the KISS approach is not without its merits, if you want to certify with minimumstress. I think half the fun is doing something risky/complex though!
Reply to
Niall Oswald
I will add that until I actually make a successful flight of my rocket, I can talk all I like but I'm not L1 certed, 'Flier X' who used a saucer to cert is and can fly H and I motors all they like!
Like I say though, getting over all that could go wrong (or at least cause me hassles) will, for me make it more satisfying when I do certify successfully. If it takes a couple of tries for whatever reason, never mind (I really hope it doesn't, I'm trying hard to think of non-destructive failure modes here!).
I'm sure this argument has been had out on here before, but I can see where people who think saucers shouldn't be allowed for cert flights are coming from. There are arguments either way, but if the flier is unknown to the RSO, flying a saucer, IMHO, does not demonstrate the same level of competence as flying a 'traditional' rocket (i.e. one with fins and a parachute/streamer). As I see it, its a bit like the difference between taking your driving test in a manual or automatic car - if you can drive a manual you can drive any car, with an auto-only license you've not demonstrated competence at what is a fundamental part of driving a manaul car.
Its not to say that the flier is (neccessarily) any less competent, but if the RSO only has the cert flight to go on (lets say the flier has travelled from a different part of the country, or is even making their first rocket flight, or they've only flown saucers...all hypotheticals I know), how are they to know if the flier can successfully pack a 'chute or determine the stability of his/her rocket.
Flame away, just my thoughts. Saucers are cool, and they do satisfy the requirement for a recovery as intended, but I'm not sure that flying a saucer is a good test of competence for an HPR flier. Perhaps a saucer with a 'chute, I don't know.
FWIW I have no issue with saucers (and their ilk) in general, I've seen some very cool flights made with them.
*dons nomex underwear, hopes for intelligent and reasoned responses!*
Reply to
Niall Oswald
Stop judging either.
The variety of methods to achieve a stated goal is the spice of life.
Now if only the goal was reduced in stature to a merit badge, 90%+ more of the population would qualify for access.
Reply to
Jerry Irvine
Can't disagree with you there.
I guess what Phil is questioning is whether 'throwing a saucer up' actually reaches the goal. On the other hand, if NAR/TRA/UKRA say it does, then it does.
How does this apply to L1 certification?
Reply to
Niall Oswald
I totally agree. I know there are some (like Art Applewhite) that totally disagree but that's just a combination of conflict of interest & not knowing any better.
Reply to
Phil Stein
Saucers are cool but as Niall said, building one doesn't show that you can do several major things right. I believe that showing that you can do these thngs sucessfully were the reason that the cert process was established. If a person can't show me that I'm not going to cert him. Of course he can go find someone else that will.
Reply to
Phil Stein
Jerry-
I don't see what the big deal is with needing a cert or not. If you don't have a cert and want one, you are going to build a rocket weather you have a cert or not. Either way, you fly that rocket. The only difference is how close a look at it someone takes before the flight. Knowing it is a first flight, the typical RSO will look it over fairly well anyway. Also, you have a few people sign off. If you fail, you get to do it again - the same as if you had passed. What is the big deal?
Reply to
Phil Stein
The cert process was established to simply show you can successfully launch an H. I was there. I know.
Reply to
Jerry Irvine

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