2 Stage - High Power - Where to Start?

I am begining down the path on my next rocket adventure. I am looking to build a high power - 2 stage rocket. Something that will take maybe up to a 54MM in the booster and a 38MM in the sustainer. I've searched TRF and read what was available.

So my questions are:

Are there any good kits to meet my needs? Or am I better off doing a scratch build?

Where can I find more information on the design of the booster? Especially around the recovery end of things?

Where can I find more information on the design and build of the interstage coupler? Any key things to keep in mind here?

I've done research on timers and it seems that the PerfectFlite are up there in quality and ability to light igniters. I have also seen the Xavian. Any thoughts frmo those with hands on experience with these timers?

Anythings else I should be thinking about?

-Greg

Do a midpower version if ya haven't already done so

I can buy into the Mid-power version first (although I have already found that I quickly want to go bigger).

All my previous questions still aplly - all help / direction is welcomed!

PML offers several two-stage HPR kits. Check RMR for articals about the Quantum Leap and miniBBX
with Terrian (sp) booster.

Stuart

Wow, great question.... I've been tossing around the same idea. I think for my first attempt at HPR dual stage, I am gonna go with the PML Thunder and Lightning. I have 1 PML kit, the Callisto, and I love the quality of the parts and the detailed instructions. Great company (no affiliation).

Mmmmm, dual stage 38mm's. O' yea !!!!

-Kurt T.

I'm finishing up the Mini-BBX right now and plan to build the Terrier booster next winter. I built the BBX stock but it can be modified for dual deployment easily enough. I plan to cut off the payload section near the bottom (where the silver paint line is) and glue in a coupler sleeve to make the alt. bay. The Terrier is already designed for a staging timer so it should be simple.

My first HPR rocket was the Callisto. Got my L1 on it. Photo Below. I agree the PML kits are nice but I have had some issues with the Quantum tubing. It tends to be suspect to breaks and creases, especially at the end of the tube.

My L2 (dual deploy) rocket I went with LOC tubing and fiberglass wrap. Very strong and durable and I think is the way I'll be going from now on. A bit more work, but worth it in the end.

After looking at the PML kits and Interstage components (and the price) I think I'll go for a scratch build. I like the feeling of creating something on your own and the added effort is not too great.

Valkrider,

Scratch building is a lot of fun and you can change things on the fly to fit your needs. I have attached a link below of a two stage I built last year that flies well and you may find a few tips in there that can help your with your design; just click on any pic to enlarge and then page through. It's also good to have a theme or set of goals. My goal was to build one model that incorporates almost all aspects of HPR Rocketry and this model included:

HPR Model
29, 38 and 54mm capable
Supersonic Sustainer
Two Stage
Cluster Motors
Canted Motors
Timers
Altimeters
Redundancy
Single Deploy
Dual Deploy
Air Start
Drag Seperation
Charge Seperation
Parachutes
Streamers

They are fun to design and build and you can take it as far as your imagination wil go. Best wishes and good luck with the project and don't forget to keep us posted on your progress! Also, here is a link to my build and I hope it comes in handy.

<a href="https://www.rocketryforum.com/ctulanko/album/index.php?dir=tres">Two Stage HPR Upscale Tres Build</a>

<a href="https://www.rocketryforum.com/ctulanko/album/index.php?display=tres%2Flaunch%2Ftres2.jpg">Tres Launch</a>

Greg-
If you know anyone that has experience wrangling deals maybe they could scratch out a deal for some motor casings for you and you could do a 5 stage 98 to 75 to 54 to 38 to 29.

The other Greg

Hmmmm, A Motor Deal?????? Now that's a thought . . . . Oh Wait, I DID THAT ALREADY!!! Someone else can run it this time.

It actually wasn't that bad and the casings are working great, especially the 54MM 1706 casing with the K550 in it Hauls @$$.

I'll be flying that motor a couple times at RocStock in less than 2 weeks. Trying to also pick up a K185 and go for the LOOOOONG Burn approach.

I prefer scratch-building -- gives you more freedom, you're not locked into someone else's ideas.

I have some pics and info about staging, including a couple ways to connect the stages:

https://albums.photo.epson.com/j/AlbumIndex?u=3009006&a=30072909&f=0

Lately I've been doing some neat two-stage flights with a 2.6" diameter rocket with a 38mm motor mount in the second stage. It uses a PerfectFlite timer which is mounted between the fins of the second stage rocket. I'm also using a PF altimeter in a separate bay just ahead of the tail section. The alt bay has a 29mm duct running through it so I can use motor ejection for backup. I'm just doing single-deploy at this time.

I'm finishing up a new second-stage that will have a 54mm motor mount, with 8 small channels between the motor tube and the airframe. Then I'll make an interstage coupler with carbon fiber rods that fit into those channels. The timer will be mounted in the coupler.

A 5 stage like an N2000 to a M1315 to a K700 to a J570 to an I200.

Greg-
If you know anyone that has experience wrangling deals maybe they could scratch out a deal for some motor casings for you and you could do a 5 stage 98 to 75 to 54 to 38 to 29.

The other Greg

Click to expand...

Originally posted by Rocket Guy 1317
A 5 stage like an N2000 to a M1315 to a K700 to a J570 to an I200.

Click to expand...

Actually I was thinking N4800 to M1315 to K1050 to J570 to I200.
More accurately I was thinking:
Central 98mm N4800 with 4 38mm J570's so the big boy doesn't have to do all the initial lifting parallel staged to two 75mm M1315's parallel staged to 4 54mm K1050's separation staged to 4 more 38mm J570's separation staged to 3 29mm I200's.
A five stage rocket in 3 physical stages.

& 18 motors, but who's counting?

Greg

Originally posted by 11Bravo
Actually I was thinking N4800 to M1315 to K1050 to J570 to I200.
More accurately I was thinking:
Central 98mm N4800 with 4 38mm J570's so the big boy doesn't have to do all the initial lifting parallel staged to two 75mm M1315's parallel staged to 4 54mm K1050's separation staged to 4 more 38mm J570's separation staged to 3 29mm I200's.
A five stage rocket in 3 physical stages.

& 18 motors, but who's counting?

Greg

Click to expand...

you forgot the C6-5

Also forgot the F39! Or the 24mm Ellis G..

I've seen the PML Terrier/Mini-BBX, Quantum Leap and T+L all flown successfully 2-stage, very cool. One of the best was Pete Davy's QL, he had a long staging delay with an AT I357 in the first stage and a Pro38 Smokey Sam in the second, which was awesome when it kicked in:

https://www.bits.bris.ac.uk/niall/gallery/EARSJune/pete10

Perhaps the coolest was Damian Hall's 'Uncle Bob' - 3" 2-stage K to K, 21000+ ft! His booster was very simple, the electronics for the second stage ignition are located in the sustainer, with positive separation of the stages via a BP charge.

https://www.rokits.org/gallery/ub-construction

Whew - Glad to see this thread has come back to reality, not that comtemplating a 5 stage rocket isn't cool!!!

I've been looking at the Quantum Leap II and it does look like a very nice package. Pretty much what I had in mind. Thanks for the links to the other build details as well. Exactly what I need to educate myself!

-Greg

Have you seen Jerry O'Sullivan's series on building a QL?

https://www.vahpr.com/qleap_precursor.htm

Also, check out his big 2-stage stuff on the same site - awesome. Watching the Nike-Nike 2-stage video should give you some ideas about why you want a good interstage coupler design!

Ordered the Quantum Leap II kit. Figured that for my first 2 stage rocket I'd pay the bit extra and start with all the parts in one bag.

I am sure I'll find a few things to modify along the way. Decided to go with the Phenolic and will be glassing. I'll post details when I get around to the build!

Thanks to everyone for your input.

I have a 54mm-38mm two stage setup. The 38mm ignition chamber in the booster section is epoxy coated, so when the second motor comes to life it just blows the booster right off. It is a very versatile rocket, as I can fly it as a short 54mm or 38mm, a long 54 or 38mm, and of coarse the 2-stage setup. It also has dual electronics bays in the sustainer for ignition and deployment.
I'm thinking about extending the booster as it will only except a 1700n motor currently, and more power never hurts.