Help me choose my L1 cert rocket! (Super DX3 vs Goblin vs Zephyr)

FlyBy01

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Hey All,

I'm finally taking the leap and going for my L1 cert. My model rocket history has been on and off but I'm finally ready to go for it. I've been doing model rockets ever since I was a little kid and my dad and I would build Estes kits. Last year I bought a few new Estes kits and finally started building them. I took my 2 year old out to a launch earlier this month and he loved the big ones so much I'd really like to get into something bigger (plus it's always been my little kid dream to have a "big kid" rocket).

Here is where I'm at. I have the funds to get just about any of the L1 kits but I'm stuck between 3 options:

Super DX3 4.0 Payloader (https://www.apogeerockets.com/Rocke...et-Kits/Super-DX3-4-0in-Payloader?cPath=1_82&)
Goblin (https://www.apogeerockets.com/Rocket-Kits/Skill-Level-4-Model-Rocket-Kits/Goblin?cPath=1_82&)
Zephyr (https://www.apogeerockets.com/Rocket-Kits/Skill-Level-3-Model-Rocket-Kits/Zephyr?cPath=1_82&)

Any advice? I feel like the one I REALLY want is the DX3 because what I'm really interested in is dual deployment. It seems like the DX3 can very easily be retrofitted to change the payload section to an e-bay. The idea would be to build it with and e-bay instead of a payload bay but fly it as a motor-eject for the actual L1 cert. Then I'm only buying that rocket to get my L1 and then get into dual deployment with something I already own.

The Goblin seems like a good choice, cheaper than the DX3 and pretty straight forward and the Zephyr seems like it's basically L1 on easy mode. Part of what I like about the Goblin or the DX3 is the challenge whereas the Zephyr seems like it's probably a lot like building an Estes kit. The glues don't scare me, I regularly work with epoxy when woodworking so it's not a new concept but a lot of what I've read about L1 is keep it simple.

Any advice would be appreciated!

Casey Levinger
Goblin of course
 

DarthDaddy762

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All great info for sure! My experience with L1 was

1. Become proficient at building a stable rocket.

2. Choose the rocket based on the field and your building skills. (Building skills and flight skills should improve over time.)

3. Learn how to sim_plan your vehicle and flight.

Enjoy the journey. L1 is about learning, improving and fun!

BTW I L1 on Zephyr with an H143!

Good day for sure!

Wish you the best!
 

Biodragen

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I did my L1 on the Zephyr
With your choices I suggest the DX3 and do a 54MM, this way you can do larger motors when you get your L2
 

bjphoenix

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I used a 4" diameter rocket for L1, essentially a LOC IV. I think I could reasonably launch it with a J for L2. I've seen smaller diameter kits that say that can be used for L2. I think these will achieve enough altitude to make recovery somewhat risky. Of course I see people putting high power motors in the Estes Big Daddy. Some people like to push the limit, other people like to play it safe. Some of the recommendations are to achieve the highest chance of success. If a person wants to accept a little more risk that's completely up to them.
 

conneryc

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As most people has said, the DX3 is probably the best option. When building a rocket for a certification flight, you want to keep it as simple as possible with minimal failure points. That is why the DX3 is probably your best option. It has the minimum number of fins needed for stability (3). The more fins, the more failure (break) points. Also you don't want a rocket with a fin design where any part of the fin extends below the body tube. If it does, that part of the fin is what will most likely contact the ground first during recovery and will take the biggest hit. Which can result in breakage. The DX3 fin shape is perfect for this as the design allows for the body tube to hit first and not an part of the fin.
 

thzero

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As most people has said, the DX3 is probably the best option. When building a rocket for a certification flight, you want to keep it as simple as possible with minimal failure points. That is why the DX3 is probably your best option. It has the minimum number of fins needed for stability (3). The more fins, the more failure (break) points. Also you don't want a rocket with a fin design where any part of the fin extends below the body tube. If it does, that part of the fin is what will most likely contact the ground first during recovery and will take the biggest hit. Which can result in breakage. The DX3 fin shape is perfect for this as the design allows for the body tube to hit first and not an part of the fin.

I'll disagree with this. Any of the rockets is fine. Keeping things "simple" is an opinion. All of these rockets have pretty darn sturdy fins, and if you bring the rocket down around 17-18fps to the ground then you won't have an issue with "breakage". If something goes wrong, i.e. parachute doesn't fully inflate, doesn't deploy, etc. then all bets are off but at that point is it really a successful cert flight?
 

AndrewGil

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I did a LOC IV for my L1, but after building the Zephyr for fun I wish I did that rocket for my L1. It is far stronger that my LOC IV that still pops fins off.
 

FlyBy01

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I don’t understand why a fin would fail if internal and external fillets are used? The only reasons I see for fin failure are high Mach speeds and recovery system failure, or too small of a parachute.
 

John_461

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The DX3 is a great choice for level 1 and 2. I suggest you fly it "stubby" (without the payload section or av-bay) on a small H to get you level 1, then get some good experience flying dual deploy on high power motors before moving up to level 2 motors. Make sure you sim first to ensure stability, but my mind-sim says you'll be fine on any 2 grain 38mm or pretty much any 29mm H.
 

Chad

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I did my L1 and L2 on the 4" cardboard DX3. It works well because 4" diameter is big enough to get your hand into and therefore easier to build. The fins aren't that tall, pretty long, and 1/4" thick so very hard to break. Being cardboard it's pretty light so the recovery gear doesn't have to be super beefy or expensive. I've always loved the DX3, all my scratch built airframes are based on its fins and general proportions.
 
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The DX3 is great, the only thing I would recommend is buying it directly from Madcow. Not sure why anyone would pay Apogee $185 for a resell rocket when Madcow manufactures the rocket and sells it for $135. Add Apogee's shipping rate of $30 (vs Madcow's $16 shipping) and you would be paying an almost 45% markup. That savings can probably buy your Level 1 motor. Maybe even your Level 2 motor.
That goes for anything Apogee does not manufacture. Look at a Missleworks RRC they are $20 more for them than the manufacturer. I called them on it and got a message from Tim. We charge more because you can call us and we will be there to help you…. Uugh, so will the manufacturer!
 

Back_at_it

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That goes for anything Apogee does not manufacture. Look at a Missleworks RRC they are $20 more for them than the manufacturer. I called them on it and got a message from Tim. We charge more because you can call us and we will be there to help you…. Uugh, so will the manufacturer!

This has been my issue with Apogee since I got back in the hobby. They are just too cocky for my liking. I also find that I have to question a fair amount of the information I have gotten from them to the point that I stopped asking questions. I still like their kits and they have a lot of really nice stuff but the attitude doesn't sit well with me when there are other brands out there that appreciate your business.
 

Chad

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That goes for anything Apogee does not manufacture. Look at a Missleworks RRC they are $20 more for them than the manufacturer. I called them on it and got a message from Tim. We charge more because you can call us and we will be there to help you…. Uugh, so will the manufacturer!
The thing i like about Apogee is when i order something it gets to me fast. I think a large part is because of geography though as they're in CO and I'm in TX. Another thing is they have a pretty wide product selection so you can order a range of stuff but only pay one shipping fee where if you were to order from a handful of other places you'd have to pay multiple shipping fees. You're certainly right about markup though, you're going to pay a markup that you may not if you went straight to the manufacturer.
 
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