Level 3 Build:Red Dragon

[cdondanville]

Here are shots of the completed electronics bay. I decided to mount the rails to the sled, instead of inside the coupler. The switches are mounted to the coupler and have the computer power molex connector on them to attach them to the board. Whole thing slides in, plug in the switches, put on the bulkheads, screw down the eye nuts and push in the key pin (through the hole in the threaded rod.) and boom, ready to fly!

[cdondanville]

I decided to go with a traditional motor mount for this as I can't see every flying anything in it but 98mm. It is not long enough to fly a 75mm M and I am not brave enough for a minimum diameter 6" rocket. I plan on getting a 4 grain EX case to fly this on as a rule. In the pictures you can see my LOC precision MMT tube. I used the centering rings I had cut earlier and cut out the proper holes for the MMT. The rear centering ring has a 1/8 layer of fiberglass on the outside. Because I could. After mounting both rings to the tube I put a U bolt in the front ring. I am going to thread the shock cord through eye bolt on the front of the motor case and attach the quick link to this U bolt to secure both to the recovery harness. The read bulkhead gets an AeroPack 98mm retainer. This is the one place where I splurge on all my rockets. I used to make all my retention until I had one of my designs impinge on the flame of a launch and feed all that heat back into the rear of the rocket. everything ended up all right, but I was left with a scorched rocket and a chipped case.

In the third picture you can see the CTI Pro98 3 grain case with the AeroPack on it ready to mark the holes on the rear bulkhead.

[cdondanville]

Building up the fin can. I used a paper pattern that goes from tip to tip of the fins. I then cut out pieces of 7.5 oz e-glass that size. I used my slow thin epoxy and laid up 3 layers on each side (12 pieces total.) I am going to let this cure and see if it needs more. This is to cut down on fin flutter and to make sure they don't pop off if they smack down hard.

[cdondanville]

To mount the MMT I scored inside the glass tube with a box cutter so the epoxy would have a place to grab. I measured the place where the upper would rest so I could score inside there as well. I then epoxied inside the upper ring with a broom handle and slid the mmt in half way. Then I expoxied around the rear of the tube and slid the MMT the rest of the way into position. Standing upright, I poured some thin epoxy in to make a seal around the MMT and grap the sides of the tube like a fillet. I will do the same around the rear when it is dry.

[cdondanville]

Working with Mark at Stickershock23.com to get the graphics and lettering.

This is the design.

[cdondanville]

Question: thinking of putting some screws through the airframe into the centering rings to add a little support against the shear between the ring and the airframe. Looking at a counter sunk #6 x 3/4 machine screw. My only worry is weakening the airframe (0.1" fiberglass) or the centering ring (1/2" birchbark plywood). Any comments on this construction technique?

[cdondanville]

And BOOM! Mark comes through with PERFECT graphics.

[Eat, sleep, and Fly]

And BOOM! Mark comes through with PERFECT graphics.

Beautiful!!!

[[POW]Eagle159]

N I C E ! ! !

That turned out perfect!

[cdondanville]

Ok, thought I would provide an update. I took Red Dragon to Phoenix Missile Works the end of March and flew her twice. The first flight on a CTI L610 was picture perfect. About 6300' and recovery in the field about 500 yards from the pad. So I packed her up again and loaded an M520 and put her up again. The up part was perfect, however the main never inflated. It knifed a fin into the red Alabama clay and ripped it loose as the body fell sideways to the ground. Ouch. No cert for you!

So I took her home and ripped the fin the rest of the way off and remounted it. I reinforced the fin can all the way around with another couple of layers of glass. Sanded primed and painted. Begged the wife and another m520 was my birthday present. Did quite a bit of research and some more ground testing to make sure I had a good chute strategy, and recovery packing.

Next chance I had was in Manchester at the HARA research launch, May 20. just before noon she was ready to go. She took off with a little wiggle but then disappeared into the haze. Got the next visual of her as she was under main at about 1100'. She came down in a field about 2500 yards from the pad. I had to wade throug about 600 yards of blackberry bushes, but she was laid out perfectly in the field and in perfect condition.

Successful L3 certification flight. 10,750' on a CTIM520 Moonburner for the 27lb scratch built fiberglass airframe. Boo-ya!

[nh4clo4]

CONGRATS!!!

Very nice rocket and a very cool choice of motor for a cert flight.

[cdondanville]

http://www.youtube.com/watch?v=VB4Wi...e_gdata_player

Video of the second flight. This is the M520 with its 14 second burn.

[Coop]

Congratulations! Well-done!

Later!

--Coop

[COrocket]

What did you end up using for tracking? I was curious because I just invested in a Garmin Astro for my rocket, and i was wondering how the Astro/Stratologger combo works.

[grouch]

Wow, how did I miss this thread? Great job Chris!!! You have had a great year in rocketry!