s6's latest - Swarmprince - 4 way cluster

The latest off my workbench - I give you "Swarmprince"

3" BlueTube with a 4 motor cluster - one central 29mm surrounded by three canted 29mm. AC ply fins, a plastic nosecone, "standard" type AV bay in the middle using a Landru 3D printed sled and Missileworks avionics.

I built this with motors in mind. What I initially envisioned is to put a longburn red motor in the middle, and three sparkies in the canted holes. Should be quite a showy liftoff, eh? Due to the canted outer motor mounts, I can only put CTI 2 grain or AT 29/40-120 motors in there. Still, lots of different possibilities to configure. I will definitely be doing some ignitor tweaks and such to "make sure" all my motors light off the pad.

I've moved into a different approach to my last few builds it seems. I've been going for "good enough" on the finish/paint, rather than trying to make it extra special. I'm still spending a fair bit of time "doing it right" sure, but I'm not obsessing, and I'm content with "decent enough". It actually feels pretty good doing this. Just don't look close!

First flight will hopefully be at the Tripoli Vegas Oktoberfest at Jean Dry Lake, Oct 17-19. I'll be burning a CTI G-54 Red (LB), and three CTI G-80 Skids. Preliminary sims tell me about 4300', but I haven't done the really detailed sim yet.

Here 'tis:


s6

WOW, any photo of the build

Awright- that is just disgustingly pretty! "Good enuff" my A$$! I hope you get fin rot....

(Jk, bro'- I'm excited to see a lift off pic- that will be hella cool!)

((d'oh! I'll be there!))

It will never fly!

Way too shiny ....:wink:

Very nice! Love the fade paint job.

that's sick!!

Very Cool!

Nice. I just realized we were parked next to each other a few Hellfires ago. I probably only had the V2 back then

A+ as usual. My video camera and I will see you at oktoberfest!


Alex

Aksrockets said:

A+ as usual. My video camera and I will see you at oktoberfest!


Alex

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Does this mean you are confirmed as going?
Still not 100% sure for myself, but working on it. Just cleared one more hurdle today - it's looking better.

s6

That looks like a great place to shove a bunch of G138T's Very nice.

That looks so cool!

Don't forget to take launch pics of this beast!

I like the motor retention for the outer motors. :cool2:

Handeman said:

I like the motor retention for the outer motors. :cool2:

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I thought that was especially clever! Can't wait to see this baby under power!

nice build, yet another piece of beauty.
One warning. Sparkies dont tend to be nice and want to light at the same time.

Well that didn't go quite as planned..........

Had the chance to put Swarmprince up in the air this weekend at the TRA Vegas October launch out at Jean Dry Lake (this was sort of an "Oktoberfest Lite" event after the real one got cancelled).

Got it all prepped and ready, checked everything once, twice, thrice, and then once more again, and hauled it out to the rail pad. Checked it all one more time, and told the LCO to let 'er rip. Well, first off I KNEW I got really lousy camera shots. It also seemed like MAYBE all the motors didn't light (some other observers thought so too, but it was hard to tell). It also seemed like it didn't go all that high. Hmmmmm. But both recovery events happened as they should, and it was easy to see where it landed. I walked out to recover and found things not so great - quite a bit of damage to the fincan where bits were burnt up and blown out. There were even some pieces of airframe that were just gone. It looked like an ejection charge fired inside the rocket and blew things apart. But I KNOW that I removed all of the motor ejection charges from all four motors (didn't I??).

So, I brought it back to my prep table to pull out the motors and see if I could figure out what went wrong. The central motor, and two of the outboard motors came out just fine. Two of them still had the tape and wadding over the front end so that was how it should be. The central motor had a very small bit of burn-through of the tape over the front end - but nowhere near enough to cause the damage that occurred, and it vented out to a different chamber that had blown out anyway. The fourth motor was stuck - I could NOT get it out of the rocket. It was also hard to tell if it had fired or not - the nozzle (that I could see) did seem a little bit charred, but not much - again it was hard to tell for sure. I put it all away to focus on launching other rockets while I could.

Now back at home, I've had some time to really dig in. I managed to pull that motor out with a LOT of whatever the opposite of finesse is, and found this:


I think this might just be the problem, no?

So, yes I had a CATO. Dang it. This one motor apparently blew up, firing forward into the sealed up portion of the fincan, and blowing the rocket apart. Swarmprince is hurt pretty bad - one of those that's unclear which makes more sense - to repair it or to start over. I'll post some pics of the actual damage to the rocket later (didn't have time to shoot any yet).

It did have a decent flight at least. My photos are awful, but here's a few of what the launch looked like:

In the last one, I think you can see a bit of when the blowout occurred. Also there are no pics of when the sparkies finished burning and that long burn red was still going - it was pretty cool looking.

Someone else was there who I believe got much better photos of the flight (they can't be any worse than mine!). If/when I get copies of them, I'll post them here.

R.I.P. Swarmprince,
s6

ouch! That's a nasty burn through.

Dave Pacheco just sent me a much better photo of the liftoff:



Pretty sweet, no?

s6

stealth6 said:

Dave Pacheco just sent me a much better photo of the liftoff:

View attachment 188686

Pretty sweet, no?

s6

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Beautifully built rocket and a very unique design. Sorry to hear how the flight ended.

Amazing photos all round as it's not easy to do. Shame about the rocket. Get onto CTI if I was you. Not had it my self but everyone here has said how good they are at helping amend these issues.

Posting a couple photos of the damage to the rocket.

Now that I've had a chance to look at it, it's obvious this was a not just an ejection charge - it was a pretty big "conflagration". The burn through alone wouldn't have happened with just an ejection charge, and large bits of BlueTube were shattered. Notice the black on the fins? - that's not a painted fade, those fins are painted solid gold. The other fins all have cracks in them along the fillets as well. The failure point along those fillets is interesting - what failed was the plywood; the epoxy and it's bond to both BlueTube and plywood held up.

I don't think this is going to be repairable. The upper half of the rocket is all fine - AV bay, recovery harnesses, payload tube, nose cone, avionics, etc. But if Swarmprince is ever to fly again, I'm going to have to build the fincan from scratch.



sigh,
s6

Yep, a rebuild is in order, any thing that can melt a hole in aluminum will make short work of body tubes. You might be able to salvage the fins.

Sorry to hear this, s6! Why do all the bad things happen to good people!?

Alex