on to my L2

Now that I'm L1 I would like to build my L2 vehicle. I definitely want to build DD and I know there are a lot of option's. Since I never built a DD I was considering a kit, but would rather scratch build it.

Any suggestions on electronics would be helpful. I wad told to exercise redundancy and also purchase each altimeter from different manufactures in case there is an issue with one make - model.

I just want a challenge and something rewarding.

Thanks in advance

My advice would be to gain some L1 experience before pursuing L2, and particularly if you want to do dual deploy, build and fly your DD bird a few times to get the hang of it before you add the stress of certifying.

As for redundant dual deploy, that's certainly an option, but not required for L2. Why not get used to flying with electronics first before going with redundancy?

It's all about learning, gaining useful hands on experience.

Ah, you've been bitten by the High Power Bug.

LOL!

Bill nailed it. Just keep flying HP until you reach the point where the motors simply aren't big enough to satisfy. In the meantime, start working on a dual deploy set up so you can get your chops up. DD makes retrieval hikes a lot shorter, especially on those windy days.

The Missile Works RRC2+ altimeter is a simple, ready to use altimeter for $50 after shipping. You could add an Adept22 or Adept's DDC22 for redundancy. The DDC22 is specially made to be a back-up altimeter, as it doesn't record altitude or stats. It comes to about $40 after shipping; so you could have a redundant system for $90.

The next question is: one or two charge wells? To be completely redundant, two altimeters, two igniters, two charge wells at each end. However, in anything less than a 4" diameter tube, you may not be able to fit two. So another idea is two altimeters, two igniters, but both going into one charge well.

As to whether or not to scratch build, that is entirely up to you. How soon do you want to certify? How much do you want to spend? How much risk are you willing to accept on your cert flight?

I am not a great builder. I much prefer flying to building. So for my L2, I bought a kit and one altimeter. I built it to spec. I flew it once on an I motor to make sure everything worked, then flew it on a baby J. Piece of cake. But I know that draws criticism from a lot of people, because I minimized my time to launch and my risk level. And I later realized that I had done some things wrong along the way, and I'm learning how to correct them.

It's kind of like how different businesses select managers. Some will say, wait until an employee is already doing a lot of management tasks, and then promote him to a management position. Others will say, put someone into a management position and then teach him to manage as he goes. I'm kind of like the latter example. I got a quick and easy L2, and now I am learning more about DD and altimeters and build techniques, etc. But many others will tell you to learn all that stuff first, and then certify.

Bottom line is, build a rocket, pass the test, and fly it on a J, K, or L motor, and you have L2. It is up to you to decide how you are going to handle those three things.

For electronics I would recommend the RRC3. Like the RRC2, but you can use the 3rd Aux channel as a backup main. I use the ground tested amount of powder in my main charge, then 1.5 sec later the backup charge (130% of main charge) fires. If the main charge did it's job you just get an extra puff of smoke, but if it failed for whatever reason you WILL get the parachute out. You may damage the payload section, but a new payload section is easier to make than a new fin can. I have needed the backup charge once. I believe one of the shear pins pulled and jammed instead of shearing. The backup charge blew the NC with authority, and all I had to fix was a 1/2" zipper in the payload section.

As for two fully redundant altimeters, going without a second is a chance I'm willing to take. With very careful setup, i.e. continuity check every connection twice, check your battery voltage and connection, motor backup (130% needed charge) to drogue charge, redundant main charges, mount everything securely, secure your charges adequately, etc. the chance of complete failure on a routine flight I would think is low.

I only have a dozen or so DD flights, but I have not had an altimeter/deployment related crash, yet with this method of care. The only close call deployments were that described above, and two instances of twisted shock cords with cable cutter DD (which were user error, not equipment error) that untangled in time to get the main open. I've gotten comfortable enough that I now use DD for anything over ~1200 ft, and I definately trust my altimeter more than motor ejection.

I am sure there are more experienced DD folks to offer opinions, but I'm only 10 months removed from my first DD flight, so maybe my perspective is closer to where you are. I will say that I don't think there should be a requisite number of flights between levels, but I have learned things with each flight, and am integrating some of those lessons into the design of my L2 rocket. My L1 rocket could have easily handled an L2 motor (and will get one someday), but I wanted to try a few different techniques which are perfectly accessible at L1 so I put the saved motor money into those efforts. After all, 2 L1 high power flights a month is still $40-80 in reloads alone, more like $60-100 when you throw in range fees, e-matches, bp, clusters, hazmat shipping if you have no field dealer, etc.).

Anyway, my 2 cents, as always YMMV. In any event, good luck.

You'll get 1,000 different ways to do your L2.

rule #1: Do what makes you happy.

DD is fun, and I like it. If you're interested, go for it. Remember, if your flight fails....you have to....OMG fly another rocket! There is no penalty for failure. No problem with going for L2 the minute your L1 lands and gets inspected. If there was a need for it, the rules would require a certain number of flights... they don't.

Personally, I wouldn't bother with redundant electronics unless the project was huge. Run one altimeter, and use the motor eject as a backup for the apogee separation.

Hey AfterBurners,

For doing your first Dual deploy would recommend a simple straight forward Altimeter.

What comes to mind are the RRC3+ and the soon arriving StratoLogger CF as both can be used as a back up altimeters in the future after you get a few more altimeters in the stable. There will also be a eGGfinder TRS coming soon that will be worth pursuing also.

Take the practice tests and get comfortable with the material, ask the vendors what Certification specials they have - THAT answer MAY dictate what rocket or scratch build you want to do and what motor...then you can decide if you want to DD or just keep it simple. Have flown my eGGtimers as a ride along altimeter for some L1 fun ..got the altitude and speed but didn't want to do the additional prep for the flights that were staying inbounds for deployment.

Scratch building will save you some dough on non FG rockets, and you can pick your components. I like LOC style rockets but try to use a BlueTube coupler with fiberglass lids for the avbays. With Fiberglass seems to be cheaper or same as a kit and usually need to buy accessories anyway.

Kenny

+1 on the stratologger. As far as using the same altimeter as a backup, can you identify a failure mode of the initial main charge that would be solved by the second main charge from the same electronics? Granted it you didn't ground test that 130% might be important. That can be avoided. The other failure modes (low battery volts, battery failure, altimeter failure, switch failure, wiring coming loose somewhere along the way) it won't help. That's why we use completely separate channels to be called a backup.

JMHO

one should keep in mind that life is a journey (with endpoints) enjoy the ride. IMO if you treat rocketry as a journey and enjoy the ride you'll be happier, there are a lot of rockets you can build(and things to do) in the L1 range of motors.
Rex

What's your rush? Enjoy Level 1 for a while!

Hey guys thanks for all the great responses to my thread and I greatly appreciate them all! What I 've noticed is after getting my L1 there are so many more options out there and I think its really cool. Maybe I'll fly some more L1 rockets for while build a few more motors and pick out a few more kits.

I think bottom line what I want is to make each build whether its a scratch build or a kit to have some challenge where I can improve my skills and become better at what I do. That's why I figured a DD would be a good starting point. I could build the rocket kit / scratch build and just fly it a lot. Stay focused on making consistent reliable flights. Once I become comfortable with flying it just launch it as my L2 cert flight.

I need to balance my time between building and flying. I like both, but don't want to spend my days just building rockets. especially if there's nothing gain from it as far as learning new techniques.

Also when I build I'm going to try to stay within a reasonable budget.

DD is definitely a good place to start. Once you do that it opens up lots of fun things (many that naturally lead to more altitude) that easier done without a really long walk.

Dan- congrats on your L1. Sorry I was so tired and wasn't much help. I was one of the last to leave but never found your cone and chute. Glad you posted up close to us. It was a pleasure to meet your girl friend-next time, let's party before you take off!

AfterBurners said:

Hey guys thanks for all the great responses to my thread and I greatly appreciate them all! What I 've noticed is after getting my L1 there are so many more options out there and I think its really cool. Maybe I'll fly some more L1 rockets for while build a few more motors and pick out a few more kits.

I think bottom line what I want is to make each build whether its a scratch build or a kit to have some challenge where I can improve my skills and become better at what I do. That's why I figured a DD would be a good starting point. I could build the rocket kit / scratch build and just fly it a lot. Stay focused on making consistent reliable flights. Once I become comfortable with flying it just launch it as my L2 cert flight.

I need to balance my time between building and flying. I like both, but don't want to spend my days just building rockets. especially if there's nothing gain from it as far as learning new techniques.

Also when I build I'm going to try to stay within a reasonable budget.

Click to expand...

After playing around in L1 for a year and a half, I just got my L2 on a 4” Madcow AGM Pike with a Prefectflight Stratologger altimeter. The year and a half was spent trying different rockets with different motors in all different weather. I also spent time practicing with the DD system. I had flown my L2 cert rocket before on L1 motors and ground tested DD plenty. As a result, I went into my L2 with a lot of confidence. There were no butterflies like I had on my L1. I bought a Cesaroni J335 and got the casing for FREE! as part of the cert special. It was a textbook flight to just under 2,900 feet and the rocket landed 100 yards away.

I really like the Perfectflight Stratologger. It’s a nice altimeter for the money. But it has features I don’t use and spent extra money on. All I needed was an altimeter that would fire charges for DD, and the RRC2 would fit that need at a little lower cost. With 20/20 hindsight, as a younger guy with a limited budget, I would have bought the RRC2 first and the Stratologger later when more experience and needs and budget warranted.

As far as redundancy, I don’t think an extra altimeter is needed for L2. Using the motor back-up should be enough. If your DD system fails, the motor eject will separate the fin can from the payload and bring the rocket down at a rate that will keep it from destroying itself or something else.

As you get into larger, heavier, higher, faster, more expensive rockets, redundant systems would come in handy. You don’t want a 12 pound fiberglass rocket with a metal tip coming in ballistic :shock:. And redundancy is needed for an L3 cert if you plan to continue. Until you get to those points, motor backup should be enough. When I eventually move to redundant systems, I’m going for 100% redundancy. Redundant batteries, wiring, altimeters, e-matches and charges. An altimeter with redundant outputs won’t help if the battery comes loose or the altimeter fails.

As for kits, I like the 4” cardboard kits that are tall enough for DD. They’re reasonably priced, easy to assemble, and fly well on L1 to low-end L2 motors. Madcow kits like the Super DX3 and AGM Pike are perfect for this. I found the Patriot’s payload bay was a bit too short for all the main laundry without having to modify the nosecone. I’m sure others will recommend many alternatives that worked for them.

As others have said, enjoy the process! Practice builds confidence. And make sure you ground test your DD charges.

Just remember, L-2 is only a credit card away!

fyrwrxz said:

Dan- congrats on your L1. Sorry I was so tired and wasn't much help. I was one of the last to leave but never found your cone and chute. Glad you posted up close to us. It was a pleasure to meet your girl friend-next time, let's party before you take off!

Click to expand...

Always good to see you Dave. And yes next time a few beers before we leave. We were both very tired. Sheryl had fun and I think made a few friends.

evil ed said:

Just remember, L-2 is only a credit card away!

Click to expand...

I decided to go with a WM Darkstar Jr dual deploy. My friend Matt will be buying the same kit but we are waiting until black Friday. And yes it will be a drag race cert 2 flight