New Rocket for LVL 2 Cert?

[JasonB]

Do I have to build a new rocket for my level two cert? Or can I reuse my Zephyr with the appropriate motor?

Thanks!

I have a Public Missiles AMRAAM 3 I am going to build if needed ... but with work time is a premium. Though a 54mm launch sounds like a lot of fun

 

[David Schwantz]

I did both L1 and L2 with a LOC 4" Phoenix.

 

[JasonB]

Nice! I have one of those also waiting for build!

 

[Bat-mite]

You do not have to build a new rocket for L1 or L2, but you must for L3, after the design/kit is approved by the TAP/L3CC. But if you did not build the rocket with L2 impulse ranges in mind, make sure it is structurally sound enough for the motor you use.

 

[JasonB]

It has rockepoxy internal and external fillets ... every joint of the motor mount except under the external motor mount ring. Other than putting expanding foam in the motor mount area I dont think i could have made it any stronger.

 

[G-Dog]

Do I have to build a new rocket for my level two cert? Or can I reuse my Zephyr with the appropriate motor?

Thanks!

I have a Public Missiles AMRAAM 3 I am going to build if needed ... but with work time is a premium. Though a 54mm launch sounds like a lot of fun

Are you hoping to certify as a NAR member? If so... then just a suggestion on my part...

Take a peek at NAR's Level 2 "Minimum Requirements"(their words, not mine),, in particular, point #6 which reads...
https://www.nar.org/high-power-rocketry-info/level-2-hpr-certification/
""6) The general expectation is that a member will gain experience with additional Level 1 flights prior to attempting Level 2 certification, as noted under “How Do I Get Started in High Power Rocketry” on the main HPR page. This could include building several L1-capable rockets and multiple flights on H and I motors. A HPR flight log will help certification teams in evaluating a member’s experience level prior to attempting a Level 2 certification flight.""

note...the above mentions the "How Do I Get Started in High Power Rocketry" which is located here...
https://www.nar.org/high-power-rocketry-info/...and states, in part...

""The expectation of the certification program is that members gain experience at each certification level prior to progressing to the next level. This would include building and flying several rockets that use one or more motors of the flyer’s current certification level. Members are encouraged to keep flight logs of their HPR flights to capture successes, failures, and lessons learned. Having this experience log will assist your certification teams when you apply for certification at the next level.""

Each of these clauses are subject, somewhat, to interpretation and my guess is that's probably by design. But, to me at least,
the *spirit*(if not the specific language) of these statements is pretty clear. I suppose, ultimately, you as a flyer and certainly the
person(s) handling your Cert process on site will probably have the 'final say'.

 

[Astronaut Cheeseball]

You could use the same rocket (Zephyr) for L1 & L2 certs as stated above. The fun of building another rocket for L2 certification broadens the learning experience and allows sometime in between certs to reflect on your accomplishments.

 

[Adam3836]

Do I have to build a new rocket for my level two cert? Or can I reuse my Zephyr with the appropriate motor?

Thanks!

I have a Public Missiles AMRAAM 3 I am going to build if needed ... but with work time is a premium. Though a 54mm launch sounds like a lot of fun

Sounds like you built it strong and the zephyr can handle a J motor all day long so should be good
Of course run some sims to see it play out on the computer but otherwise let it rock

 

[Hobie1dog]

Sounds like you built it strong and the zephyr can handle a J motor all day long so should be good
Of course run some sims to see it play out on the computer but otherwise let it rock

+1

 

[JasonB]

I got my NAR number few months ago ... i have done two launches with my Zephyr so far ... H182 and I280 ... i see what you mean about multiple launches and builds though ... I have to build the AMRAAM at some point might as well build it do a 38mm I motor on it and then lvl 2 it after on a 54mm

i have toyed with the idea of getting a Katana and doing dual deployment on my level 2 ... send it with the goal of 10k. We had a 14k wavier last month

 

[mtnmanak]

I recommend you convert your Zephyr to a dual deploy bird by adding an ebay and a payload bay. This is a pretty simple conversion. Fly it a few times on H & I motors to ensure you got the build right and your dual deploy system works, then use that rocket to get your level 2 on a small J. I have two Zephyrs and converted both of them to dual deploy and fly them on J's frequently. It is a great bird and the process of converting it to dual deploy will give you some great level 2 skills while providing you with a rocket you can test safely with Level 1 motors until you are sure it is good. Then, when you fly it for your Level 2, it will just be another launch instead of an anxiety producing experience.



I also have a PML AMRAAM. Great rocket as well. However, it is not as simple to build due to the quantum tubes and piston eject system. Those components add complexity. Also, unless you are planning to modify the AMRAAM 3 or use a Jolly Logic chute release, Rocksim is showing that an PML AMRAAM 3 will go to about 5000 feet on even the smallest J motor. That would be a pretty high Level 2 flight and may cause a very long walk or even a lost rocket on a single deploy flight.

My dual deploy Zephyr flies to less than 700 feet on a small J and bumping that up bit gives you a nice low and slow dual deploy flight on cert day. I would aim for a nice 1200 foot flight with mains opening around 500.

 

[Arpak]

I got my L1 and L2 on the same Zephyr. I agree with mtnmanak, you definitely want to convert it to dual deploy before doing it, a J270 takes it close to 3500ft if I recall correctly, that's a bit of a walk.

 

[JasonB]

great thank you for the info! I used a Jolly Logic on my 2nd Zephyr flight because it was an estimated 4k flight on the I280 ... we have a large dry lake bed for an area.

ill keep everything im learning stewing around in the brain housing group... ! Thanks

 

[thzero]

Design and build your own.

 

[Steve Shannon]

Do I have to build a new rocket for my level two cert? Or can I reuse my Zephyr with the appropriate motor?

Thanks!

I have a Public Missiles AMRAAM 3 I am going to build if needed ... but with work time is a premium. Though a 54mm launch sounds like a lot of fun

Neither NAR nor Tripoli require you to build a different rocket for L2, but over the years it has been discussed, probably by every board. I don’t think such a rule is needed, but I would like to see some flyers get more experience between L1 and L2.
Having said that, why do you feel the need to do your Level 2 now? You say you are short on time because of work and I would suggest that nothing is gained by hurrying to do your L2, especially if you’re time crunched in your life. Fly the Zephyr on several more motors, including some higher thrust ones, convert to dual deployment if you’d like, gain some experience. Add a camera. Test some electronics. Learn. Then, when you have the time to build the AMRAAM, take what you’ve learned and apply it. Then do your L2 on whichever rocket you want.

 

[Philip Tiberius D.]

Not to highjack a thread but... just doing some Sunday morning thinking before my coffee (Peet’s - Major Dickenson Blend) really kicks in... with an EggTimer Apogee deployment system and either a JLCR or Cable Cutter (Aerocon Systems for example) what is the advantage of Dual Deployment? A streamer or drogue parachute can be released at apogee then the main at what ever altitude you decide. True it’s electronics heavy but so is the traditional Dual Deploy, is their some advantage on DD (other than possibly higher drag on descent from the “laundry line”) ? I see a small advantage is less weight possibly.... Thoughts? Comments?

 

[mtnmanak]

Not to highjack a thread but... just doing some Sunday morning thinking before my coffee (Peet’s - Major Dickenson Blend) really kicks in... with an EggTimer Apogee deployment system and either a JLCR or Cable Cutter (Aerocon Systems for example) what is the advantage of Dual Deployment? A streamer or drogue parachute can be released at apogee then the main at what ever altitude you decide. True it’s electronics heavy but so is the traditional Dual Deploy, is their some advantage on DD (other than possibly higher drag on descent from the “laundry line”) ? I see a small advantage is less weight possibly.... Thoughts? Comments?

I do use JLCRs on many of my rockets, great piece of kit. For smaller Level 1 motor eject rockets, it really is all you need most of the time.

The big difference as the rockets get bigger is that the parachutes get bigger. I find the JLCR less reliable on larger chutes because there is too much stress on the pin. At some point, Dual Deploy is just more reliable. Once you get to the point that you have redundant dual deploy computers on board, it is very unlikely that the dual deploy system becomes the point of failure on a launch.

For me, the line is somewhere around a 36" parachute. Anything above that and I feel like I am in Dual Deploy Territory. I know a bunch of people who are comfortable flying a JLCR with larger parachutes, but I just don't want to deal with the uncertainty at that level.

Interestingly, very small diameter rockets also benefit from dual deploy. I just built a 29mm minimum diameter rocket with full dual deploy. I tried fitting a JLCR in the 29mm tube and it was tighter than I was comfortable with. Considering this rocket will fly to over 10,000 on an I motor, I decided to go full dual deploy. Worked out great.

At the end of the day, I have had a JLCR fail on me (pin got stuck), but I have never had a properly designed and tested dual deploy system fail.

 

[Dan Griffing]

Do I have to build a new rocket for my level two cert? Or can I reuse my Zephyr with the appropriate motor?

Thanks!

I have a Public Missiles AMRAAM 3 I am going to build if needed ... but with work time is a premium. Though a 54mm launch sounds like a lot of fun

I used my L1 Zephyr for my L2 with a J270 motor. But I went much further than necessary by adding Apogee’s dual deployment kit with an 18” main chute airframe compartment. I also added an Eggfinder GPS as well so that I could track my rocket to avoid losing it.

A level-2 motor will send a stock Zephyr so much higher, that motor ejection near apogee could result in the rocket drifting so far that it gets lost. You can’t get your L2 cert if you lose your rocket.

But dual deployment adds a lot of new complexity to your rocket and it all needs to work perfectly for a successful launch.

 

[Dan Griffing]

I recommend you convert your Zephyr to a dual deploy bird by adding an ebay and a payload bay. This is a pretty simple conversion. Fly it a few times on H & I motors to ensure you got the build right and your dual deploy system works, then use that rocket to get your level 2 on a small J. I have two Zephyrs and converted both of them to dual deploy and fly them on J's frequently. It is a great bird and the process of converting it to dual deploy will give you some great level 2 skills while providing you with a rocket you can test safely with Level 1 motors until you are sure it is good. Then, when you fly it for your Level 2, it will just be another launch instead of an anxiety producing experience.

View attachment 463359

I also have a PML AMRAAM. Great rocket as well. However, it is not as simple to build due to the quantum tubes and piston eject system. Those components add complexity. Also, unless you are planning to modify the AMRAAM 3 or use a Jolly Logic chute release, Rocksim is showing that an PML AMRAAM 3 will go to about 5000 feet on even the smallest J motor. That would be a pretty high Level 2 flight and may cause a very long walk or even a lost rocket on a single deploy flight.

My dual deploy Zephyr flies to less than 700 feet on a small J and bumping that up bit gives you a nice low and slow dual deploy flight on cert day. I would aim for a nice 1200 foot flight with mains opening around 500.

My L2 cert was with a dual deployment converted Zephyr on a J270W. The onboard Altimeter3 recorded an altitude of 3032 feet. The launch weight of the 75.4” rocket was 8.25lbs.

 

[KB4SMK]

I did my NAR level 1 and Level 2 on the same day with the Same Rocket. Madcow 4.0 Nike Smoke single deployment.

 

[Philip Tiberius D.]

I do use JLCRs on many of my rockets, great piece of kit. For smaller Level 1 motor eject rockets, it really is all you need most of the time.

The big difference as the rockets get bigger is that the parachutes get bigger. I find the JLCR less reliable on larger chutes because there is too much stress on the pin. At some point, Dual Deploy is just more reliable. Once you get to the point that you have redundant dual deploy computers on board, it is very unlikely that the dual deploy system becomes the point of failure on a launch.

For me, the line is somewhere around a 36" parachute. Anything above that and I feel like I am in Dual Deploy Territory. I know a bunch of people who are comfortable flying a JLCR with larger parachutes, but I just don't want to deal with the uncertainty at that level.

Interestingly, very small diameter rockets also benefit from dual deploy. I just built a 29mm minimum diameter rocket with full dual deploy. I tried fitting a JLCR in the 29mm tube and it was tighter than I was comfortable with. Considering this rocket will fly to over 10,000 on an I motor, I decided to go full dual deploy. Worked out great.

At the end of the day, I have had a JLCR fail on me (pin got stuck), but I have never had a properly designed and tested dual deploy system fail.

All good info, thanks.

 

[ThirstyBarbarian]

I recommend you convert your Zephyr to a dual deploy bird by adding an ebay and a payload bay. This is a pretty simple conversion. Fly it a few times on H & I motors to ensure you got the build right and your dual deploy system works, then use that rocket to get your level 2 on a small J. I have two Zephyrs and converted both of them to dual deploy and fly them on J's frequently. It is a great bird and the process of converting it to dual deploy will give you some great level 2 skills while providing you with a rocket you can test safely with Level 1 motors until you are sure it is good. Then, when you fly it for your Level 2, it will just be another launch instead of an anxiety producing experience.

View attachment 463359

I also have a PML AMRAAM. Great rocket as well. However, it is not as simple to build due to the quantum tubes and piston eject system. Those components add complexity. Also, unless you are planning to modify the AMRAAM 3 or use a Jolly Logic chute release, Rocksim is showing that an PML AMRAAM 3 will go to about 5000 feet on even the smallest J motor. That would be a pretty high Level 2 flight and may cause a very long walk or even a lost rocket on a single deploy flight.

My dual deploy Zephyr flies to less than 700 feet on a small J and bumping that up bit gives you a nice low and slow dual deploy flight on cert day. I would aim for a nice 1200 foot flight with mains opening around 500.

Your advice seems spot on to me. But are you saying that dual deploy Zephyr in the picture only goes to 700 feet on a baby J? I would have guessed much higher. My Warlock goes higher than that with an extra payload section and a load of Halloween candy. I’ve watched a number of Zephyr L1 flights to around 1500 feet on H motors, and it seems impossible one would go only half that on a J, even with that addition of a dual deploy setup. How much does it weigh, and what motor are you using?

 

[Dan Griffing]

Your advice seems spot on to me. But are you saying that dual deploy Zephyr in the picture only goes to 700 feet on a baby J? I would have guessed much higher. My Warlock goes higher than that with an extra payload section and a load of Halloween candy. I’ve watched a number of Zephyr L1 flights to around 1500 feet on H motors, and it seems impossible one would go only half that on a J, even with that addition of a dual deploy setup. How much does it weigh, and what motor are you using?

ThrustCurve rates the J270W as a low level “baby” J compared to other Js. But it sent my 8.25lb Zephyr DD to 3032 feet.

I agree that its implausible for a Zephyr DD to go only to 700 feet on a “baby” J.

https://www.thrustcurve.org/motors/AeroTech/HP-J270W/

 

[mtnmanak]

You guys are right, Rocksim is throwing some really odd numbers at me. Looking back at my previous flights, they are much higher than what Rocksim is now showing. I built this file in Rocksim 9 and have since upgraded to Rocksim 10.2. I think this may be the problem.

I am going to try and rebuild the .rkt file and see if I can figure out why Rocksim is giving me wonky numbers. It would be a real pain if I can't trust my old files and need to rebuild them in Rocksim 10.

 

[ThirstyBarbarian]

You guys are right, Rocksim is throwing some really odd numbers at me. Looking back at my previous flights, they are much higher than what Rocksim is now showing. I built this file in Rocksim 9 and have since upgraded to Rocksim 10.2. I think this may be the problem.

I am going to try and rebuild the .rkt file and see if I can figure out why Rocksim is giving me wonky numbers. It would be a real pain if I can't trust my old files and need to rebuild them in Rocksim 10.

Yeah, that would definitely be a pain. Hopefully that is not it, and it’s some kind of global preference-type setting that is off. I use OpenRocket and am not familiar with Rocsim, so I’m not sure what it could be.

But your advice on adding an AV bay and payload for the Zephyr and testing it out on lower altitude L1 motor flights is still good, and a J motor flight with an apogee at 3,000 and main at 500 or so is a totally reasonable L2 flight.

I kept my L2 flight a lot more simple with the Warlock on a J290 to around 2,000 feet, motor eject, and Chute Release at 500 or 600 feet. Very easy and satisfying. I’m not an altitude junkie, and I like my flights simple. But that Zephyr to 3,000 dual deploy sounds good.

 

[Handeman]

I see two problems with using the same rocket for L1 and L2. The same basic problem applies to using a 29mm MPR to do a L1 cert.

The first is you get much higher altitude on a L1 rocket when you fly it on a J motor. The discussion of JLCR and DD makes it obvious this is a major consideration.
The second it that the L1 rocket is usually a 38mm MMT and a small J is all that will fit. You still need to build another rocket with a 54mm or 75mm MMT if you want to fly any L2 motors other than baby Js.

Everyone can approach the L2 cert how they want, but my advice has always been, build a rocket for the cert level you are attempting, and build it to fly the range of motors that cert level allows. That is pretty easy to do for L1 with 480 Ns from smallest to largest, but becomes harder for L2 where the motors covers a range of 4.480 Ns. Getting experience with 54mm K motors is a good step before going to the 75mm Ls.

I always felt learning to fly your field is a large and essential part of each cert level. Part of that is understanding the power the motors have. It takes a while get enough experience to understand the power range of H & I motors. When you start on the J to L range, the learning curve is much steeper, but even more fun.