Super Neon 3XL^2 - If I have to explain why, you won't understand

So a couple of years ago, I purchased a bunch of Super Neon XL kits when Estes was blowing them out. I didn't become the rocket reseller I dreamed of becoming, and still have a bunch of these sitting around. So, while working on another couple of projects, I got to thinking:

3 x BT-20 tubes fit in a BT-60, right? And the Super Neon XL is based on a BT-60. Hmm... That's not exciting enough. Hmm... Two stages, with air-gap staging... OK, that seems more like it!

So, along with building 5 other rockets (Cosmic Interceptor, three scratch built rockets, and switchblade rocket glider), apparently I need to start another project. RockSim/OpenRocket files attached. One cut tube, move the fins to the upper stage, add an ounce of nose weight, and it's theoretically good to go. Now I just need to get it built by Saturday, provided that we actually have a launch (it's fire season). Will try to do a build thread. Kinda. We'll see...

View attachment Super Neon 3XL.ork
View attachment Super Neon 3XL.rkt

We didn't have the launch, and then I found mold AND termite damage in the basement, which is where I was building my rockets. I've been slightly distracted. However, the rocket is almost ready to fly this weekend. Here are the non-standard bits:

Building the cluster mounts - basic three tubes with thrust rings. Rocket is in the background preparing to be trimmed into two stages


Add the motor hooks


I like to glue a piece of scrap body tube over the motor hook, especially when there isn't really anything else holding it in


Both mounts, finished


Once everything was ready, I added a Semroc centering ring. I also added balsa triangles to the rear so that there would be more contact surface for the glue

The booster mount has the bottom of the motor tubes flush with the bottom of the booster


The sustainer mount sticks out about 3/4", so as to act as a coupler. It's still kinda loose.



Final assembly, with paint.


I still need to:

• attach the shock cord to the sustainer and nose cone
• add the launch lug (why do I always forget these)
• drench the inside of the booster stage with thin CA to protect it from burn-through
• add a vent hole
• add something to make the booster-sustainer connection more secure. The sustainer wobbles a bit. I'm thinking balsa squares, then sanding down until I get a good snug fit.
• oh, and add that ounce of nose weight that I put in the .ork file but forgot about.
• and the decals. Must remember those

So, if I want to fly just the NC and the booster stage on 3 x C5-3's, I need 6 oz of weight to get one caliber of stability, and would attain a whopping 350' at apogee.

View attachment SNS.ork

Because I was looking at them, and thought, "why not?"

First flight will be Quest B6-0 staging to Estes B6-6. I realized that I didn't include a chute in the sim files. Either a 15" or 18" nylon chute for the sustainer, depending on how windy it is; booster gets old-fashioned tumble recovery.

75Grandville said:

...[*]add a vent hole...

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I would suggest three vent holes in the booster tube so they are outside of each of the three sustainer engine nozzles. Really cool cluster-booster design! But wouldn't this be a Super Neon 6XL? Or maybe a 2X3L?

GlenP said:

I would suggest three vent holes in the booster tube so they are outside of each of the three sustainer engine nozzles. Really cool cluster-booster design! But wouldn't this be a Super Neon 6XL? Or maybe a 2X3L?

Click to expand...

Actually, per the decalI made, it's a 3XL^2 (I updated the thread title)


Estes has an advantage - they print white under their waterslide decals so they show better. Note for future reference - purple on purple doesn't work at all...

I like the new name.

I have had trouble with decals over a painted color, I wanted bright yellow letters decal over blue paint, but they turned out looking dark green. You would have to use the white background paper and trim around each letter individually.

I have tried painting decal paper to color match the rocket background before printing the decal sheet in the ink jet printer, but it just did not work.

Did you say you had a few kits? You could trim up the stock decal sheet to make new letters, maybe...

GlenP said:

I like the new name.

I have had trouble with decals over a painted color, I wanted bright yellow letters decal over blue paint, but they turned out looking dark green. You would have to use the white background paper and trim around each letter individually.

I have tried painting decal paper to color match the rocket background before printing the decal sheet in the ink jet printer, but it just did not work.

Did you say you had a few kits? You could trim up the stock decal sheet to make new letters, maybe...

Click to expand...

Or I could just contact Mark at Stickershock... Which I will probably do, if the rocket does OK this weekend. Peel off the waterslide decals, and put some vinyl on there. With nice vivid contrasts.

So, overall a successful flight. All three Quest B6-0 (German) lit, and launched. All three sustainer motors lit, parachute came out, landed safely.

The good:

• Booster burnout was at 36 ft, per OpenRocket. There was a slow liftoff, then the second stage lit and disappeared. Very cool effect!
• Motors lit on both stages
• All bits recovered successfully!

What I would like to improve on for next time:

• The bits of balsa that I used to keep the sustainer in place got chewed up by the ejection charges of the first stage
• The booster hit the ground hard, on one of the tubes, and bent the tube. It actually bounced back up into the air!

My thoughts:

• Add BT-50 pods on either side of the sustainer, to hold streamers or parachutes for the lower stage
• Coat the balsa blocks with something to retard burning. Or just plan to replace on a regular basis
• Wondering how long the booster will stay intact, before it burns through.
• Wish I had taken pics/video

75Grandville said:

...The bits of balsa that I used to keep the sustainer in place got chewed up by the ejection charges of the first stage
...
...Wondering how long the booster will stay intact, before it burns through....

Click to expand...

Did you add any vent holes in the booster tube just below the sustainer engine nozzles? That might help alleviate some of the torching in the tube and on the sustainer if you give the hot gasses somewhere else to go. They do make some high-temp BBQ paint which might also help.

flat black header paint from napa should work as well

fm

Yes, did add vent holes. Maybe they need to be bigger. May drill them out.

Added pods so that I can attach a recovery device to the booster. My first attempt involved splitting a BT-50, but that didn't work out so well. I wound up with 3.75" BT-20 pods, topped by balsa NCs from Starlight. Glued in place, then hit it with another shot of metallic green.

Here it is drying after the first coat, hanging from my poor man's rotisserie. Cosmic Interceptor just got a clearcoat.