A Question of Clusters

DizWolf said:

Hi my name is David and...... and screw you I don;t have a problem!!!! I just need 2 more 24/40 cases....the loads come in three packs....it makes sense!!! and I don't like cleaning at a launch...what if I need to fire off a cluster i haven't built yet and someone needs to borrow a case to get a cert? It's in the yard sale for $20 less than retail!!! I have to get it now... and IT'S A MILLENNIUM CASE!!!!!!

ummm.... Clusters are cool.

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LOL brother, you got more backbone that I do-I never let my wife see all the cases together at one time. Same way with reloads. And parachutes. And altimeters. And rockets...

fyrwrxz said:

Clusters are a gateway drug to ruin. Once the dealer gets you hooked, it wears off as your tolerance builds and you need a better high. Then you go for airstarts. and then you add stages, then you are walking on traffic medians carrying a sign the says "Will work for motors". By now the kiddies are asking for shoes and wondering where daddy is. Your ex-wife says something like "Probably out wandering around in the desert looking for his thousand dollar rocket." Sadly, you;ve become an HPR junkie and all your Estes friends have dropped you. You can't fly in the park, you have an unsightly fiberglass rash and your boss has fired you for downloading Rocsim on your work station. All because of one little extra engine. But all is not lost. We're your friends here. We accept you as you are. We are here to help. Hi- I'm Dave and I can't quit buying cases.......

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Uh, thanks there, fyrwrxz... I guess you've certainly showed me what lies down that road, if I should choose it....:sad:

Maybe I won't build that cluster rocket after all...

Quest motors seem like they have thinner walls than Estes, and they also have a paper label that I've usually have to peel off to use. But they seem to work just fine, and they make more smoke and noise than Estes. If you want Q2G2 igniters for clustering, then I'd just go ahead and buy the Quest motors, and use those with the Q2G2 igniters that come in the package. You get great igniters and a loud smokey burn for your cluster launches.

Kirk G said:

Uh, thanks there, fyrwrxz... I guess you've certainly showed me what lies down that road, if I should choose it....:sad:

Maybe I won't build that cluster rocket after all...

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No, No , NO! You gottit all wrong-it's GOOD to cluster! Here's why:
1) It gets you out in the fresh air
2) You get to work off calories walking about with your tracker
3) Doesn't rot your teeth
4) More vendors will know you by first name on sight
5) It's a hobby the whole family can enjoy-once you teach the kids to build reloads
6) you gain the respect of all the guys flying 1/2A motors (okay- just the ones that don't cluster, or have gliders, or small dogs and/or chldren)
7) The RSO spends way more time with your rocket-allowing you to bond
8) You get your own groupies, worshipping at the pillar of fire and smoke (okay may be not so good if you have an established religion that doesn't serve Kool-aid, just roll with it)
9)You get to be the last guy away from loading the pad. You get recognition.
10) The pictures are awesome!
Just try one cluster...it's a game changer!

fyrwrxz said:

LOL brother, you got more backbone that I do-I never let my wife see all the cases together at one time. Same way with reloads. And parachutes. And altimeters. And rockets...

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I had them all together for one photo. Then back into hiding places. One over the broomhandle, couple in the toilet tank. Hollow out a couple table legs... Duck tape a few under the coffee table...

Why clusters? Why not clusters! For my two motor clusters, I just twist the ignitor leads together. For three motor, I solder extensions to the ignitor leads so I can twist them all together. I've never used a clip whip, never saw the need. I've only ever used Estes ignitors with clusters. Never had a problem with them.

Clustering is as much Art as Science. That said I'd MUCH rather cluster then use AP motors. That's actually how I got the club nickname mrcluster back the the 80-90's when I was up-scaling everything clustering D12's.

There are several Great new options to cluster ignition unfortunately the best of them The Quest Q2g2 very low resistance igniters are apparently in very short supply and may not be returning.

Add to that the NEW pyrogenless White tipped Estes igniters and you have a real potential for missed ignition in clusters. Estes Solar igniters (with Pyrogen) or hand dipped are the ONLY Way to Go with clustering. And each and every igniter MUST be checked before, During and AFTER insertion in the motors to be sure they are still good. Check, Check, Check! those igniters for continuity. Last check should be on the pad.
The other most important issue with cluster ignition is ample current. you need to get the most amps (Minimum 2amps per igniter) to the igniters as quickly as possible. This means moving the Battery power source to the LAUNCHER side of the system away for the controller. This is best done with a Relay ignition system employing continuity check at the pad not the controller.
If your interested in reliable Cluster Ignition of BP motors up to 12 then I strongly suggest checking out the Tech-Tip 006 "Clustering BP motors" in the library section of www.narhams.org which will give you an in-depth look at what has to happen in those first milliseconds after we push the button to have all motor come to life.





View attachment Cluster Wiring Diagrams-2c_Dwg(Revised)_09-17-12.pdf

It's all been said.
I'll just add more visuals.:eyepop::y:


-Ken

I totally dig clusters. Keep the pictures coming!

Original 1960s era clusters were necessary because an 18 mm motor was limited to a B because of the original thick casings. To lift a bigger rocket you needed 2, 3 or 4 B motors clustered.

Later we got the D13 motor ( now a D12).

Gary Byrum said:

I use the clip whip method also, but with a different approach than what SBoomer mentions. One lead from each starter is twisted together, and one of the firing leads connected. The other 3 leads are connected to the clip whip (which has 3 wires of it's own ) and the whip is connected to the other firing lead. If you can get Quest Q2G2 starters, I highly recommend them. I had a very successful ignition with this approach, The red lines in the pic below represent the clip whip.

View attachment 184734

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This is the way I do it, three engines, two Micro clips. (12 volt system!)
The longer leads on the Q2G2 igniters make it much easier to twist the ends.
The insulation on the wires eliminate any possibility of shorts.

The Estes igniter (starters, whatever) are bare wire, another reason I prefer the Q2G2s for clusters.

Micromeister said:

Add to that the NEW pyrogenless White tipped Estes igniters and you have a real potential for missed ignition in clusters.

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Out of interest, why are the new "starters" more of a problem for clusters? Without pyrogen, you need to be more careful to make sure that they're in good contact with the propellant, but then that's a problem for single motor rockets too. Of course, the result of not making contact with a single motor is less serious, it just means the rocket doesn't go anywhere whereas a cluster with one motor that didn't ignite is liable to go off course. But I've used some of the new types and so far have had 100% ignition, albeit only on single motor rockets - I haven't tried them in a cluster.

So, apart from the need for extra care when fitting them, is there something else about the new "starters" which makes them less reliable for clusters? Do they draw more current than a Solar igniter? Because eventually those nice Solar igniters are going to run out... (I'm going to hoard the things, use "starters" for single motor rockets, and keep the Solar igniters specifically for clusters. )

What you said in the 1st paragraph. If the igniter blows in a sinle-motor config, stick in a new one and try again. But in a clustered config, if half the motors don't ignite, you risk having a catastrophic situation.

adrian said:

Out of interest, why are the new "starters" more of a problem for clusters? Without pyrogen, you need to be more careful to make sure that they're in good contact with the propellant, but then that's a problem for single motor rockets too. Of course, the result of not making contact with a single motor is less serious, it just means the rocket doesn't go anywhere whereas a cluster with one motor that didn't ignite is liable to go off course. But I've used some of the new types and so far have had 100% ignition, albeit only on single motor rockets - I haven't tried them in a cluster.

So, apart from the need for extra care when fitting them, is there something else about the new "starters" which makes them less reliable for clusters? Do they draw more current than a Solar igniter? Because eventually those nice Solar igniters are going to run out... (I'm going to hoard the things, use "starters" for single motor rockets, and keep the Solar igniters specifically for clusters. )

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The black pyrogen on the solars create a bit of flame which makes placement just a little less (but not much) critical than with the new starters (which only glow red hot). This is based on observation of several test firings outside of a motor. I don't recall seeing any data on current draw of starters and whether it differs from the solars.

Drop a few grains of 4F BP in each nozzle before installing the Estes 'starters'. Makes placement less critical.

Try 241 D motors and 9 C motors in a 16" air frame. Appox. 4900 newtons ( probably 4200- 4400 actual)

[YOUTUBE][video=youtube;oeAsY_D6un0]https://www.youtube.com/watch?v=oeAsY_D6un0[/video][/YOUTUBE]

Why clusters? Next question! :surprised:

Back to your original questions. I use a clip wip for lack of another term . More like an umbilical and wired to suite the motors as needed. About 24 inches long to follow the rocket up the rod a bit. I think of it as insurance for a late start. Anyway, --why cluster?? You have been tossed into the mix. You have a kit you most likely would have never bought. Staging is cool and the best way to go for altitude- some times--most of mine are in another country now--. Here is how things normally go leading to clustering. Launch..... That was a little slow and scary-must of built it a little heavy-hmmm? Maybe I can strap on a couple boosters. Well that did'nt work, might need some weight in the nose. Launch--ooowwwww, how cool. I'm gonna play with this stuff now-----time goes by-----now I'm going to scratch build a cluster just because I can--hmmm wonder what a staged cluster will do---well that worked out well--now I'll try a gap stage cluster. You see where this is going by now. The point is -your already hooked , so go with it. Your gonna learn a ton. Did I mention fall off boosters--sooooo cool--Air starts, It just keeps going !!

I buy a lot of Estes Blast Off Flight Packs and I go through the B's and C's fairly quickly but end up with a lot of excess A8-3's. When the club is launching from one of the smaller fields, I launch my Semroc Defender a couple of times on three A8-3's and that uses up my excess motors pretty quickly.

fyrwrxz said:

Clusters are a gateway drug to ruin. Once the dealer gets you hooked, it wears off as your tolerance builds and you need a better high. Then you go for airstarts. and then you add stages, then you are walking on traffic medians carrying a sign the says "Will work for motors". By now the kiddies are asking for shoes and wondering where daddy is. Your ex-wife says something like "Probably out wandering around in the desert looking for his thousand dollar rocket." Sadly, you;ve become an HPR junkie and all your Estes friends have dropped you. You can't fly in the park, you have an unsightly fiberglass rash and your boss has fired you for downloading Rocsim on your work station. All because of one little extra engine. But all is not lost. We're your friends here. We accept you as you are. We are here to help. Hi- I'm Dave and I can't quit buying cases.......

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Listen to him Kirk. He knows where of he speaks. Once you're hooked, you're hooked. There's no going back!

Verna
www.vernarockets.com
https://www.amazon.com/dp/B00HHJHOK6/?tag=skimlinks_replacement-20
https://www.facebook.com/RocketBabeDustStorm

Verna said:

Listen to him Kirk. He knows where of he speaks. Once you're hooked, you're hooked. There's no going back!

Verna
www.vernarockets.com
https://www.amazon.com/dp/B00HHJHOK6/?tag=skimlinks_replacement-20
https://www.facebook.com/RocketBabeDustStorm

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Getting motivated late Sunday night, and with an eye on the calendar for our next club launch, I decided to tear into the Semroc "Scrambler" kit with a three cluster engine. Starting at 1:30 a.m. I got most of it together by 3:30 a.m. in stages, that I let set and dry. I diluted some Elmer's Carpery glue to a slury and sealed all the balsa, including sanded fins, and left them out to dry. I love Yellow Wood Glue cause it is forgiving, and you can reposition or tack it in place and it will dry overnight.

Getting up at 6:30 a.m. cause somebody's alarm went off, I took the engine housing which had cured, and inserted it into the body tube and glued it well, leaving it in position to dry. Rising at 11:30 a.m. again, I walked an errand and found a large golf umbrella waiting for trash pick up. I rescued it, walked home and after a light sanding, feathered the fins and began gluing the three on.

Over the course of two hours, I not only feathered each fin, but also used wood filler to patch a dog chew on one, and glued them in place, one by one. As the last one cured, I stripped the golf umbrella of the green and white skin, and trashed the bent ribs. I checked the final fin and discovered the overhead fan had rocked the body tube and the fin had faallen over! Quickly, I picked up the fallen fin, reapplied glue, and repositioned it at the proper angle. It was drying nicely as I left for work, about 12 hours after I started the rocket. Other than final assembly of the parachutes and the priming and finishing with paint and decals, the assembly is basically done. Now to either find an egg, or a 4" action figure, for the clear plastic payload, and I might be ready to launch by the weekend!

(Sorry, didn't think to snap any pictures yet...)

But here's an idea that's been in the back of my head for a possible 4" "action figure" for the clear payload section...
https://www.comics.org/issue/17568/cover/4/

That's right... come to the Dark Side! :dark:

Verna
www.vernarockets.com
https://www.amazon.com/dp/B00HHJHOK6/?tag=skimlinks_replacement-20
https://www.facebook.com/RocketBabeDustStorm

Been obsessively thinking about building a 3" 3x24mm rocket. Any thoughts?

CzTeacherMan said:

Been obsessively thinking about building a 3" 3x24mm rocket. Any thoughts?

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What's to think about? No Brainer-24mm reloads come 3 to a pack-yeah? Gopher it!

fyrwrxz said:

What's to think about? No Brainer-24mm reloads come 3 to a pack-yeah? Gopher it!

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That's what I was thinking!... Project to tackle after my L2 build.

CzTeacherMan said:

Been obsessively thinking about building a 3" 3x24mm rocket. Any thoughts?

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Yea, do it in a 2.6"

CzTeacherMan said:

Been obsessively thinking about building a 3" 3x24mm rocket. Any thoughts?

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I just finished a 3" x 7-24mm. Maiden launch last month on a G-145 p and 4-D-12 airstarted

DizWolf said:

Yea, do it in a 2.6"

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Any problems using AT 24/40 casings when the mounts are that close together?

I am looking forward to flying this (probably at october skies). Haven't flown clusters before, but a central 24mm mount and 3 18mm mounts should provide lots of thrust and a ton of motor combinations.

CzTeacherMan said:

Any problems using AT 24/40 casings when the mounts are that close together?

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never tried it, but theres a bit of room to space them out. I think it could be done. these were designed for BP so they touch, if you pushed them out to the wall I think it'd be ok, then just run an all thread in the middle and use a nut over a washer to retain all three.