Advice on a CAR L1 and L2 Rocket

[DavidInNS]

(i tried several searches and scrolled back a few pages in this section, but I couldn't find the information I was looking for. My apologies in advance if I missed a key thread and this is yet another repost.)

I've decided I want to go for my CAR L1 and L2 cert so that I can fly H and I motors, respectively. There seem to be so many choices and options that the more I read about them the more I'm driven to the edge of sanity! ;) I would love some advice from people who have "been there, done that" to give me their thoughts based on what I've found.

I'm trying to find a nice balance between style, flying options, and cost. I would love a kit that would be light enough that I could put it on a rail (now that i've sourced a 3m stick) with a G motor and not need to worry about waivers, but at the same time can hold up to H and I motors when I get the chance to go to high power launches.

In the style department, my taste in scale kits seem to gravitate toward designs such as a Patriot M104, Amraam, or Tomahawk. Non-scale kits that have interest in the style department include things such as LOC's Hi-Tech H45, EZI-65 (I love that fin design and the way they look), and LOC IV. I've been trying to consider kits that have a 38mm mount as I can always adapt down for those G flights.

Am I asking too much from just one kit in this regard (being able to fly mid or high power) in the style/price range I'm considering?

As an aside, I really like the PML Amraam kits, but their charts showing they need to be strengthened for certain flights (in I impulse class) combined with their FAQ saying they need to swich from QT to phenolic to do it may put the cost of their kits out of my reach. Does anyone have any comments on needing to strengthen the Amraam 3 to fly I motors?

I also want to say as an aside that I'm grateful to everyone who helped with my launch rail question in another thread, and I hope you'll put up with me asking such a basic HPR question that's probably been beaten into the ground. I appreciate your patience! :)

[jms]

I bought the Mad Cow Super DX 3 for my CAR L1 which I hope to challenge this fall. It's a great kit, and in my humble opinion, a perfect bird to build for cert flights. It also sports a very large payload section (don't glue the nose cone on!) which can allow you to get your feet wet with electronics.

Sodmeister (from Manitoba) I think did his CAR L1 on it, and he's send me photos, given me build tips, and helped tons along the way. So between him, me and I know there's a number of other Canucks who've built the DX 3.

I ordered mine from Apogee, as well as the 38mm Cesaroni starter set (6 grain case, 3 grain case, 2 spacers and the ProDAT tool), and don't forget to buy a motor retainer. I bought the Aeropack tailcone style (I only ever saw people use the flat retainers on this bird so I thought I'd be a bit different).

To round it out, Mark from stickershock23.com and myself put together a custom vinyl design for it called "Toxic Thunder".

As for build progress: yesterday I finished the internal fillets on the fins. I used a double wood glue joint on both the MMT and the inside of the airframe. Because it's plywood to kraft tube, a wood glue joint is going to be far stronger than the fin itself and much lighter than epoxy. My wife and I epoxied in the rear centering ring, and I drilled the holes through the upper air frame and into the nose cone.

I am using neoprene well nuts (auto body supply store had them) to hold on the nose cone, which are great because you have to really force them in and even without securing with a machine screw the nose cone is not coming off. When you drive in a #8-32 machine screw it actually sucks the rear of the neoprene tight against the inside of the nose cone. I can also then remove three of the machine screws and the well nuts will still give retention while also being holes for altimeters.

I am hoping to finish off this build today, and if the weather doesn't turn ugly I'll throw down my first coat of primer on it.

[DavidInNS]

wow thanks for such a great response!

I have some questions about ordering over the border (I too looked at apogee and the DX3), but im running late for work so I'll PM you when I finish my 12 hour shift of doom! :(

[jms]

Yeah, there might be a better place to buy in Canada. Drop me a PM and don't hesitate to hit up sodmeister, he's extremely helpful and has actually flown his Super DX 3 :D

[bobkrech]

The 3" PML AMRAAM kit would be fine for all 38 H-motors, most 38 I-motors and even a few 38 J-motors. The potential problems are related to fin flutter at lower transonic velocities. If you order the QT kit with 0.093" thick fins instead of the stock 0.062" fins, you should be fine.

Also note that PML uses a piston instead of wadding for recovery. That's fine, but the PML directions have incorrect instructions for building and installing the piston. A piston should have the bulkhead at the bottom end of the piston, and the open cup should face the NC and contain the chute. This results in a stable piston configuration that releases smoothly. http://www.deltavrocketry.com/piston.htm

Bob

[Threemorewishes]

Hello DavidInNS,

I did my CAR L1, L2 and L3 all on a modified LOC IV. L1 was done in the almost stock configuration and L2 and L3 in a stretched configuration. The stretched configuration included an electronics bay and an upper body tube section.

The only modification I did to the stock configuration parts was to swap out the original fins for ones that butted up against the motor tube. I think LOC includes feature in the kit now.

Good luck with what ever kit you choose.

Greg

Here's a few pictures of the L1 and L2 certification flights.

L1 in stock configuration on CTI H 143Smoky Sam.
http://img.photobucket.com/albums/0903/MuddyTires/MellowYellowH143SmokySam.jpg

L2 in stretched configuration on CTI I350 Smoky Sam.
http://img.photobucket.com/albums/0903/MuddyTires/MellowYellowI350SmokySam.jpg

[CF-105]

Four inch airframes are my favourite "general purpose" size. I got my CAR level 1 on an Estes/NCR Archer, and later built a clone that flew on J's.

That size range includes the PML Patriot, and there are lots of other kits in that range. Greg mentioned the Loc IV. PML makes several other 4" kits (Tethys comes to mind), as does Loc/Precision, Mad Cow and others. Even the Aerotech G-Force flies great on H's (and maybe I's - I forget if I tried that) with only modifications to the motor mount, and still stay under the weight restrictions for "model rockets" with a G.

Ultimately, it's your decision though, and should fit your style and what you're comfortable with. You could cert on a Loc Mini-Magg (5.5" stubby thing) or a PML Cirrus Dart if you prefer. The biggest caveat is: remember that you have to get it back so the RSO can inspect it.

There's a fellow in Fredericton that retails plastic model kits, that can also bring in Mad Cow. We have a CTI motor vendor locally who can bring in PML; for Loc and Aerotech I think most of us order from Coast Rocketry way over on the other coast...

Greg - are those photos from a long, lost Blazing Archer? That tarmac looks familiar...

[sodmeister]

I believe SIGMA(Ontario) deals with MadCow ,LOC and Aerotech ,CTI and a whole lot closer than BC.

Paul T

[DavidInNS]

wow thanks for the replies everyone! hopefully I addressed everyone's comments here:

Good call on the Aerotech kit. I liked the DX3 but I had concern about being able to launch it on "hobby" motors.

bobkrech - thanks for the heads up on the Amraam kit. That's good to know and makes it easier to keep it in consideration.

Greg - I believe you are right. I remember reading something about that in addition to coming with a 38mm motor mount stock. One of the things I liked about the LOC IV was what seemed to be a "straightforward" build combined with good looks. And that smoky sam really gives it a presence for sure! :)

Kevin - I think I know the CTI motor vendor. I think I met him when I was a spectator at the Rage 2 years ago and he's a member of a yahoo user group. Thats the main reason I'm considering CTI motors over Aerotech (easier access)

[Threemorewishes]

...Greg - are those photos from a long, lost Blazing Archer? That tarmac looks familiar...

Hello Kevin,
Good eye. They are indeed from a Blazing Archer launch. It's the only memories of that rocket I have left as it was lost at LDRS24.
See you on the field.
Greg

[Blackfly]

As with Threemorewishes post, I would recommend using a single rocket for 2 or three levels of flight. Spend the extra funds on motors & a good recovery system.

IMHO, a 4" quantum rocket is fully capable of K-impulse flights. Build it well and it will be a thing of beauty. Bluetube is another solid product that I've recently upgraded to, as my projects are leaning towards mach+ flights.

Colin at Sigma Rockets can get everything you need, and more, and he's wonderful to deal with.

Coast rocketry also has excellent service, and with 5 day fed-ex shipping, a 7lb 36" box shouldn't cost more than $35 to ship, coast to coast.

Blue skies,

Patrick

[CF-105]

Hello Kevin,
Good eye. They are indeed from a Blazing Archer launch. It's the only memories of that rocket I have left as it was lost at LDRS24.
See you on the field.
Greg
You lost that, but recovered the Big Daddy?? The rocket gods are indeed capricious!

David - That's another point I forgot to mention: whatever you end up with, install a 38mm or larger motor mount, regardless of what the kit comes with stock. Adapters will let you flight smaller-diameter motors.

[sodmeister]

That`s what is nice about the DX3 ,very stable design (check CP/CG) and very durable with good building practices.

I did my level 1 & 2 on it and it was flawless.Could do level 3 on it also if you wanted.

Friend did his level 1 & 2 on DX-3
Brother did his level 2 on it.

What can you say ;)

Paul T

[DavidInNS]

whatever you end up with, install a 38mm or larger motor mount, regardless of what the kit comes with stock.

fer sure! :)


That`s what is nice about the DX3 ,very stable design (check CP/CG) and very durable with good building practices.

I did my level 1 & 2 on it and it was flawless.Could do level 3 on it also if you wanted.

Friend did his level 1 & 2 on DX-3
Brother did his level 2 on it.

What can you say ;)

I say its a kit thats in contention for sure! :)

[jd2cylman]

Dump the pistons and use Kevlar chute protectors and shock cord protectors. No piston jamming ever.

Another LOC kit that would work is the IROC. 5.5" dia. w/38mm MMT. Light enough for a H123 and heavy enough for a J350. An added plus is that it's big (ish).