Go Devil 54 for L1/L2 cert questions

[jwheat632]

So I recently bought the Go Devil 54 kit for my L1/L2 certification. My university rocketry club is helping guide me through how to build it, however they've never built a minimum diameter(md) rocket kit and this is the first rocket I've ever gotten. I've researched motor mounting on md rockets and have found 2 options: friction mount and md retainers. Does anyone know which of the two would work best/another method that would work better for an L1/L2 rocket?
Also are they're any specific types of motors for md's vs a traditional style rocket? Or would the motor retention be the only difference?
Furthermore, if anyone has built this kit and has any advice, it would be much appreciated.

 

[llickteig1]

You can't certify on a team built project. The flyer must build it.

Imo, 54mm minimum diameter rocket is a very poor choice for certification.

You should go to a launch and discuss motor retention with experienced flyers. See how they do it. Then decide what you're comfortable with.

 

[jwheat632]

You can't certify on a team built project. The flyer must build it.

Imo, 54mm minimum diameter rocket is a very poor choice for certification.

You should go to a launch and discuss motor retention with experienced flyers. See how they do it. Then decide what you're comfortable with.

Sorry, bad wording. They're guiding me through the build process as far as teaching the basics and answering questions as we build. I'm doing the actual building. They just don't know some specifics for how to build a minimum diameter kit and wanted me to do some research and get back to them so they could help guide me through the build.

 

[mikec]

Imo, 54mm minimum diameter rocket is a very poor choice for certification.

I agree, they usually go really high, requiring dual deploy, and have some setup issues.

You have three off-the-shelf options: friction fit (lots of things to go wrong), a forward retainer (works but can't use smaller diameter motors) or a standard retainer on the back end (adds drag depending on what type you use.)

 

[GaryT]

You can't certify on a team built project. The flyer must build it.

Imo, 54mm minimum diameter rocket is a very poor choice for certification.

You should go to a launch and discuss motor retention with experienced flyers. See how they do it. Then decide what you're comfortable with.

I'd have to say I totally agree with llickteig1 on this one, 54mm MD isn't the right rocket for L1 and L2. Needless to say can do whatever you like, but my recommendation would be for L1, build your rocket dedicated to your L1 say 4" Dia and a 38mm MM with motor eject at apogee.

L2 build another bird say 4" Dia 54mm MM and Dual Deploy, I only say this because in the long run you will have learned multiple techniques well! your not under the gun to do to many unfamiliar things all at once, take your time concentrate on the L1 and don't even think about the L2 till its time for that chapter, you take what you've learned in you L1 build and apply it to your L2 build when its time. Just my 0.02$

 

[David Schwantz]

Hey Wheat, I have built and flown this rocket. I have used the MD retainer in the tube, but this will not mount all motors. I also used friction fitting with tape wrapped around motor casing. But I use aluminum tape around the nozzle and the rear end of the tube. It getsfolded over around the back of the nozzle also. i have not lost one yet like this. As others have said, this might be a better choice for a second rocket. it will go out of sight. Cert flights are great if you see the whole flight.

 

[dhbarr]

Build your sim with an i600r and a j500g. Ponder whether and how you'll get it back. Then make more design trades.

 

[OverTheTop]

Your rocket will do about 21k' and something like Mach 1.8, give or take, on an L motor, if built sufficiently well.

It might be good for L1 with a motor adapter. If built right it will happily take J motors for L2 without much trouble. It will not be a low and slow flight and you are likely to need tracking.

As to whether it is a good choice or not is between you and your TAP or certifying person.

Good luck with your journey .

Personally I would suggest building two rockets for the two levels. You will learn things with each build. YMMV.

 

[cwbullet]

Your rocket will do about 21k' and something like Mach 1.8, give or take, on an L motor, if built sufficiently well.

......

Personally I would suggest building two rockets for the two levels. You will learn things with each build. YMMV.

I agree. You need to add the RSO to the list of approvers. The problem is you really need to know who it will be on that day and where you will fly. We have a 15K waiver and I have had a couple of flyers show up expecting to fly 15K. They forget the 10% rule.

Pick a rocket that you and your TAP and Prefect are happy with and your field can support. As a Prefect that certifies level 1 and 2 flights, I recommend a lower and slower flight for level one. There is nothing more distressing than building up that perfect flight only to lose track just before it pops the main out. You watch that dot in the sky drift out on the horizon feeling helpless. You have the glimmer of hope as you search in that direction for days.

I have lost more rockets than I can count, but none of them were cert flights.

 

[dr wogz]

And I'll chime in as another who will say:
Keep it simple
Keep it in sight
Remember, this rocket, for either L1 or L2 or both will [hopefully!] be flown other times, not just for these two attempts. You will want to try different motors, to achieve different results, and reach different goals / expectations.

That standard for achieving L1 or L2 (or L3!) is build one for L1, then build another for L2. You'll soon discover you want things in your L2 that you don't for L1 (Such as DD, tracking, redundancy, etc..) Building: the skills & techniques are harder than you might think! They take practice, time & patience to get good results..

Since you don't seem to have any experience, I would suggest you go with an L0 type MPR rocket first. Get something with a 29mm Motor mount, about 2-4" dia, cardboard & plywood. Build it and fly the stink out of it; F & G motors.. Get used to flying it in different conditions & configurations, building motors, and how a club launch works. Talk to other club members, they well be the biggest & best influence you can have for success. Know what the numbers mean, and how to differentiate the results from the different numbers. You'll also see it's a bit cheaper than trying to continually fly L1 or L2 motors at every launch. You can also get more flights in, being MPR.. Once you can do these flights routinely, the L1 flight will be like any other.. And you'll have the confidence to achieve it!

 

[David Schwantz]

I agree with wwwwwhat has been said except foooor I do not see anything wrong with the same rocket foooor 1&2 cert flights. Maybe not a Go Devil54MD, but I did both of mine on the same one. just put 3lbs in the NC to balance her. Flew greeat and could see both flights all the tme.

 

[David Schwantz]

Sorry, key pads are starting to stickk.

 

[jwheat632]

Hey Wheat, I have built and flown this rocket. I have used the MD retainer in the tube, but this will not mount all motors. I also used friction fitting with tape wrapped around motor casing. But I use aluminum tape around the nozzle and the rear end of the tube. It gets folded over around the back of the nozzle also. i have not lost one yet like this. As others have said, this might be a better choice for a second rocket. it will go out of sight. Cert flights are great if you see the whole flight.

Hi David,
I understand what ya'll are saying in that this would be better as a second rocket, however the whole program is set up by the university rocketry club to get new members some experience by building a rocket and being certified through NAR for L1/L2 before being put on an actual team. They intended for us to use one rocket for both and told us that 54 mm would be preferred. I've committed to the Go Devil so I'm at least going to give it a try.

Since you've built this kit and flown it, I have a couple other questions if you don't mind...(sorry if I get any terms wrong)
1. How did you set up the recovery system for your rocket/how would you recommend I set mine up (deploying parachute mainly). I also plan on using a tracker.
2. I saw some other users suggest using an adapter for a 38 mm motor for my L1 flight, then switch to 54 mm for L2. I'm assuming that would be my best bet. The club is providing the motors and wants me to get suggestions on which motors would work. Do you have any suggestions? I plan on going with the friction fitting for motor retention.

 

[David Schwantz]

if I were to use this MD for a L1 cert, I would remove the payload section, put NC right on the booster, and fly motor eject. A small H motor in 38mmmm with the adapter would fly her great. Use Open Rocket or rocksim to get the right motor choice afteeer you know all up weight. Check rail exit speed and max alt. Try an H100W-14A and see what it says. I used AT H283ST for my l!, but it was a big bulky rocket. Hit max alt a 600agl and popped chute at about 222222222200agl. Pucker facttttor on that one. For the L2 flighttt you could still fly with no payload section, use a JLCR to deploy main at 500 or 600 feettt. If you want to use electronic and DD, then reinstall the payloooad section, build your Av bay. You can use a streamer as a drouge, chute is not required. But both work. Again you can use a 38mm for an L2 flight. I have flown mmmine on J250 a K550rms, do not use that one for the cert flight, you will never see it after about 1 second. it is nice to see the event happen, also your TAP and Prefect may require seeing them for the flight. Good luck, and feel free to ask anything you need. Also, since you want to fly this on severalll different motorsss, you may need to add and remove weiiiight from the NC. there are seveeeral ways to build this into it. I like to use a removableee bulkhead setup. LOC makeeeees the RNWS, I have used it and it works well. Jason may have one that fits youuur NC, he is grreat to deal wiiiith. damn sticky keys.

 

[ben]

Wheat - what school and where are you planning on certifing? NAR or TRA.

Ben

 

[jwheat632]

if I were to use this MD for a L1 cert, I would remove the payload section, put NC right on the booster, and fly motor eject. A small H motor in 38mmmm with the adapter would fly her great. Use Open Rocket or rocksim to get the right motor choice afteeer you know all up weight. Check rail exit speed and max alt. Try an H100W-14A and see what it says. I used AT H283ST for my l!, but it was a big bulky rocket. Hit max alt a 600agl and popped chute at about 222222222200agl. Pucker facttttor on that one. For the L2 flighttt you could still fly with no payload section, use a JLCR to deploy main at 500 or 600 feettt. If you want to use electronic and DD, then reinstall the payloooad section, build your Av bay. You can use a streamer as a drouge, chute is not required. But both work. Again you can use a 38mm for an L2 flight. I have flown mmmine on J250 a K550rms, do not use that one for the cert flight, you will never see it after about 1 second. it is nice to see the event happen, also your TAP and Prefect may require seeing them for the flight. Good luck, and feel free to ask anything you need. Also, since you want to fly this on severalll different motorsss, you may need to add and remove weiiiight from the NC. there are seveeeral ways to build this into it. I like to use a removableee bulkhead setup. LOC makeeeees the RNWS, I have used it and it works well. Jason may have one that fits youuur NC, he is grreat to deal wiiiith. damn sticky keys.

Thank you so much for the suggestions! This should give me enough info to point me in the right direction. As I research more and begin to plan the build/begin building, if I have anymore questions I'll post in here.

Wheat - what school and where are you planning on certifing? NAR or TRA.

Ben

Hi Ben,
University of Alabama and the Club is planning on using NAR for the certifications.

 

[manixFan]

Ok, so this may be an unpopular opinion but I did my L1 on a dual-deploy PML Sudden Rush, which I also used for my L2. My L1 was my first flight on anything bigger than a D motor. Shortly after that I built a PML Nimbus, a 54mm MD rocket. That was 15 years ago and the Nimbus flew at LDRS this year. Below are photos of how I handled motor retention. It's a Slimline retainer that is feathered into the body tube with filled epoxy. I cut slots in the fins to allow the retainer to slide on all the way. I use the Slimline 54mm to 38mm adapter to fly smaller motors, which is shown in the second photo. I routinely fly it on K185s and K550s, as well as a variety of smaller 38mm motors.

I have built many MD rockets since and now use internal motor retention. But the Slimline method shown below has worked well.


Tony

 

[cwbullet]

[/QUOTE]

And I'll chime in as another who will say:
Keep it simple
Keep it in sight

I am going to have to put that in my quote book.

 

[dr wogz]

I am going to have to put that in my quote book.[/QUOTE]

I should have also added:

Keep it on site.

 

[Nytrunner]

Thank you so much for the suggestions! This should give me enough info to point me in the right direction. As I research more and begin to plan the build/begin building, if I have anymore questions I'll post in here.


Hi Ben,
University of Alabama and the Club is planning on using NAR for the certifications.

Ah, more Alabama rocketeers! Where do you plan to certify?
Your main challenge is going to be getting this (high altitude) rocket to come down on the field (and not land in a tree). Dual deployment or a chute release is an absolute must. I strongly recommend your team/club/program invest in a tracker like the eggfinder products or the missileworks T3.

The suggestion of flying L1 without the payload tube (motor deployment charge and single chute, maybe a chute release) is a good one.
Then when it comes to L2, you'll add the ebay and payload tube, stick the drogue in fornt of the motor, and the main in the payload tube (called traditional dual deployment). Apogee Components has many good videos that could help you and your team learn rocket techniques.

 

[blackjack2564]

What mid power rockets have you built/flown to date and..........

Why this for a L-1 and 2 ?

Do you have a tracking device.
know how to dual deploy?
Built ejection charges and correctly sized them?
Know what motors by definition are required for L-1 and 2?
size a drogue & main?


If ya do then:
Build the rocket with correct epoxy...no tip to tip required.
take the easy route on retention. glue an aero-pac on tube and done.
Get/borrow a 2 grain 54mm case and a spacer.

Fly L-1 on a 1 grain reload54, with spacer in 2 G case: depending on type of propellant you will attain approximately 2500-3000 ft per grain [based on weight ready to fly sans motor 2.5-3.5 lbs]
Fly L-2 o n 2 grain reload in same case with no spacer to about 4500-5500 ft using 2 grains.

If you do not understand what I am talking about, don't attempt this....

 

[Nytrunner]

If you do not understand what I am talking about, don't attempt this....

Or if you do decide to attempt it, at least you know more things to research

Why this for a L-1 and 2 ?

Universities (and their students) don't have much money for this stuff

 

[SammyD]

cwbullett was considering a new quote for his quote book above: "Keep it simple; keep it in sight", and the person who authored the quote added "Keep it on site". +100 on those three things. I understand the rush, but you miss so much that L1 and L2 fliers know intuitively by not starting small and working your way up at whatever pace you choose. The questions I hear you asking are questions you really should have a pretty good handle on by the time you're ready to certify L1, and you should DEFINITELY know those answers by your L2 flight.

I'll add another quote that we used to use in Virginia for certification flights: "Low and slow". In other words, don't launch something that you will not be able to see to apogee and back to the ground (keep it in sight), and don't put a monster motor in. Fly enough motor to get it to 1000', maybe 2000' or 3000' if you dare (keep it simple) That's all that's needed, AND you stand a much better chance of bringing the rocket back safely and undamaged (undamaged and able to fly again is a cert requirement).

For what it's worth I spent a lot of time in Mid-power because I could launch 10 rockets a day and spend less money than some of the guys flying bigger rockets but getting only one flight per day. Big rockets and big motors have their place, but you can get a LOT of bang for your buck flying mid-power. I did it for like 4-5 years before going to L1, then flew lots of mid-power and a number of high-power L1 flights until I got my L2 a year later. I've now been at L2 for nearly 5 years and feel pretty content here for now...

 

[blackjack2564]

Universities (and their students) don't have much money for this stuff

Yes, but having worked with programs like this...wondered why a minimum diameter rather than...say a 3 in. with 54 hole or some other more forgiving kit. Doing a minimum right out of the box with no experience is a bit nutz..unless there are some mitigating circumstances.

 

[Nytrunner]

is a bit nutz.

So are most rocketeers, so he should fit in just fine B)

It's definitely more challenging, but -if he does the research and takes his time- not impossible.

 

[mbeels]

....but you can get a LOT of bang for your buck flying mid-power.

Very true. And it is way fun.

 

[Mailman]

Build light and go with the I65 for your L1!!!

 

[Mendal]

I never personally understand rushing through L1 and L2 there is so much knowledge to be gained in these levels and flying rockets at these levels. I think it is a shame that a university program is rushing a flyer to get levels. Your levels are something that you should take pride in the fact that you earned them, and just because you have earned a level does not mean that you know all there is to know about that level.

Even if you put a GPS tracker on this you are going to run into some major issues tracking as this rocket can easily surpass the lockout speed of basically all commercially available GPS systems. I would suggest not only dual deploy but redundant electronics for deploy ment and plan for GPS and Radio trackers.

I know you are "commited" to the Go Devil but your odds of a unsucessful level attempt are rather high. If you lose the rocket or crash on a Level attempt it would be a lot more costly then if you had built a less intensive build for your Level one. I did my level one on a Madcow Super DX3 (cardboard airframe with a 38mm MMT) It was built well and has flow more times then any rocket I own.

A 38mm J motor would be enough to obtain a L2 cert.

I just encourage you to really think it through before you decide for sure. I am not saying it can't be done, but the path ahead is difficult to say the least.

Good luck however you choose to proceed.

 

[OverTheTop]

It's definitely more challenging, but -if he does the research and takes his time- not impossible.

I agree. The same path is not a requirement. It does depend on the person. Personally I jumped from D motors to L1 (certified on an I). It is a path that should not be taken lightly, but if well-considered and with some decent background (people and/or engineering theory) it is not out of the question. As long as they are not on the extreme left of the Dunning-Kruger curve they should know what path is sensible.


https://en.wikipedia.org/wiki/Dunning–Kruger_effect

 

[Nytrunner]

t is a path that should not be taken lightly, but if well-considered and with some decent background (people and/or engineering theory) it is not out of the question. A

+1