Started a new Micro 6-motor cluster model

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Micromeister

Micro Craftman/ClusterNut
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I've been kicking this design around for a little while now. 6 MMX-II's gives me 1.86Ns or a mid level A thrust level so I'm using a fairly large but short section of BT-20 main body tube with a couple outboard pods just for fun.
I'm still in the building stages on this model so the only photo out of the camera so far is one of the aft end showing the cluster arrangement.
As I develop this model I'll share more. Overall; if built as envisioned the model will be about 8-9/32" long with a fin span of 2.875". Should be a fun and Fast flying cluster:)

MM 370uc07b_business end 6 MMX cluster_05-22-10.JPG
 
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Truly mad. Mad as a hatter. A micro rocket-building hatter. :roll:

Clustered Micromaxx? Somehow that seems to fit, John. I'm having a flashback to a certain PMC project from awhile back... ;) :D

I've wondered from time to time about clustering my FlisKits Mud Wasp. But 6 motors in your project? This should be interesting.

MK (barking mad, myself)
 
Here is a little ditty I was working on for the Manned Spaceflight contest.

MMX3clusterP1015728.jpg


It is a three MMX cluster...
MMX3clusterP1015698.jpg


And I thought I was way out there....
:shock:

Six MMX?
Woof....

So when do we see more of your build?
 
No Layne, not even close, MAD is when you try to make a Mach attempt on a MMX motor, now that's MAD.

SD, a person who has been MAD :D

SD:
You have to keep in mine that to many Mach attempts mean less then nothing. Particlually at this scale. sort of like the Micro Powered H level model. sort of a fun exercise to ponder but not worth the cost or trouble to produce.
We have all kinds of really interesting stuff to work on keeping within the realm.
 
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Layne:
That's a pretty neat looking little cluster of three. Very nice design.

LOL! Yes Mark, the XB-70 is a fun flying in-line 6pack. This one won't be anywhere near the same LOWt.

Well, since I've sort of let the cat out of the bag anyway I guess I should start at the begining.

This model got it's start from a Club Activity. We're in the process of a Kit-Bash contest, the contest will be running the rest of this calander year. We each purchased a spacific bag of parts and can use nothing except the things in or on that bag of parts and envelope with the contest instructions.

As I was thinking about what to do with that model I came up with the micro version. As usual I like to make everything in Microsize so this is just an extension of that. I'm calling this little beasty the MM KBK-10 Cosmic Cluster.
The first photo below is sort of the pattern sheet/design I'm working from. It's not a completed or done drawing so it is not for others to build from, you can if you wish but know it has not be simmed or tested in any way. I Know this model will require a decent amount of nose weight just because of all the motor weight in the end.
Anyway heres where & how we started:)

MM 370uc01_MM 6motor cosmic Cluster Plan Drawing_05-07-10.JPG
 
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Before I went to far I layed out the Main transition light cardstock (67lb) cone and made a couple extras just to practice on. while I was at it I cut and fit the forward centering ring for the core cluster, then printed the reduced fin patten and motor tube spacer strips on file folder to get things started.

Over time flying Micro clusters I've found it is most helpful to be able to completely externally tape the motors as well as a bit of friction fitting tape inside. Since starting this practice I've only kicked a single engine from a PMC that I didn't have a good tight seal on anyway.

MM 370uc02_Cardstock Main trans & cluster ring_05-07-10.JPG

MM 370uc03_File Card Fin Pattern &  parts_05-07-10.JPG
 
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Decided to use Flis parts for the forward transition and all nosecones just to be lazy. Man it's just great to have quality Micro parts easily accessible.
T3/T2.5 Balsa Transitions is partically hollowed out for a loop of 90lb kevlar set in epoxy.
Main T3-AD nosecone just gets a little CA soaking on the shoulder base to harden it up some. Those two T2.5-AD external power pod nosecones also get a couple layers of epoxy to help them stand up to the ejection charges of the motors.

While those pieces set up we cut the 1/32" basswood fin pieces, dry fit, then carpenters glued up. For a bit of extra strength they are then sandwiched in high rag onion skin tracing tissue attached with thinned Elmer's carpenters glue. plased between Wax paper and pressed under a couple heavy books overnight. The result were quite pleasing. absolutely 0% wrinkles.
I did change the fin pattern slightly...making the flat end aft rather then forward as it was intended...didn't even notice the goof until I had them on the model:(

MM 370uc04_Hollow out Transition_05-21-10.JPG

MM 370uc05a_dryfit pair of 2 piece fins_05-21-10.JPG

MM 370uc05b_4 - 2pc fins glued up_05-21-10.JPG

MM 370uc06_4 fins in tissue sandwich_05-21-10.JPG
 
John is there an alternative motor geometry for a 6 engine cluster? I'm interested in finding the most efficient way to fit 6 18MM BP engines in a single body tube.
 
After fitting up all the T2+, T3 and BT-20 parts with Flis or custom cut centering rings and finishing the attachment of the core 4 motor cluster in the main body, I attached a beading wire 49strand stainless steel shockline anchor to the T3/BT-20 transition ring base before coating it with epoxy and installing it in above the cluster mount. Slide the formed up 67lb cardstock main transition in place with just a bit of 5minute epoxy around the base. To strengthen the transition cone it is CA soaked with a paper towel mop making sure to rub it well into the fibres.

Sorry some of these activities didn't get photos as I was building this one along with the Larger model and sometimes I missed pics of duplicate steps. CRS sometimes takes over don't ya know:)

after marking the BT-20 for the two external motor pods, and the epoxy has set hard on the Nosecone/tube joints. they are added on cardstock standoffs just like the internal tubes. I've also extended them about half way to bring the motor nozzles flush with the end of the main Cluster motors when installed. After giving the carpenters glue time to cure both external pods get epoxy fillets. After that has cured the fins sets can be attached to the pods and set to the proper angle. Here one set of fins are in place standing to show the fin angle. Last photo shows all 4 fins set with finished epoxy fillets complete.

MM 370uc07a_MM body parts together_05-22-10.JPG

MM 370uc08a_ 1pr fins attached_05-22-10.JPG

MM 370uc08b_4 fins epoxy fillets_05-22-10.JPG
 
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John is there an alternative motor geometry for a 6 engine cluster? I'm interested in finding the most efficient way to fit 6 18MM BP engines in a single body tube.

There are seveal ways to stack motor tubes, It's really going to depend on the ID of you main body tube. 6 Bt-20 (18mm) motor tubes fit tightly in a BT-70 with a core tube and 5 outside, there may be a little distortion if either tube is not held to the exact spec. That's about as fine as I've ever really looked at it.
 
First of the detail builds will be the fintip laser cannons. these took a little work to find tubes small enough and ended with a .050" carbon fibre rod.

Curving the 1/32" basswood fintips just a little to help seat the cannon was kinda fun with a micro Launch lug wrapped in a piece of 220 sandpaper.
after roughing up the surface well yellow glue and epoxy fillets should keep them in place.

so far heres the over all base look. front and side views.

MM 370uc09_4 tiny laser cannon_05-23-10.JPG

MM 370uc10a_fin tip laser cannon mounted_05-23-10.JPG

MM 370uc10b_fin tip cannon mounted_05-23-10.JPG

MM 370uc11a_OA base model side_05-24-10.JPG

MM 370uc11b_OA base model Front_05-24-10.JPG
 
To make the tiny 1/8" launch lug nose and tail cones we'll use a stick if 3/16" hardwood dowel, a hand drill, files and sanding sticks. cutting them off the stick with a Hobby knife an carefully fitting them inside the LL's with some yellow glue.
Standoffs are 1/32" basswood also paper laminated just for fun.

MM 370uc12a_begin turning .188in dowel NC's_06-04-10.JPG

MM 370uc12b_finished LL size NC_06-04-10.JPG

MM 370uc12c_1 of 4 LL size dowel tail cones_06-05-10.JPG

MM 370uc12d_all 4 forward Pods_06-05-10.JPG
 
Adding the Forward pods and beginning conduit attachments with .045" styrene it's starting to look like the drawing.
next will be to make the two matching Radar antenna arrays, ducting and attachment standoffs. These have me a little worried. Making the dishes for the larger model I used a water soaked center form one of the BT-20 centering rings, forming it over a marble. but these are gonna be like the center of a T2+ centering ring? We'll SEE...

MM 370uc13a_Forward Pods attached_06-11-10.JPG

MM 370uc13b_Forward Pods Attached_06-11-10.JPG
 
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Over the weekend I had some time to work on both the full size and micro versions of this design.
Making the antenna arrays for the MMX model was really kinda fun! Used a fiber center from a T2+ centering ring to mold the radar dish pans, splitting off the disks from the layers. created the curvature by wet forming them over a small plastic bead. Once dry I attempted and failed to glue them centered over a second disc serving as the assembly bulkheads. They'll be OK later I'll even them up somehow LOL!!!
Next needed to put the collector spikes in place. These proved to be challanging as I had to split a piece of 1/32" styrene to make something small enough. employed a 1/8" hole punch to produce the small internal disc for mounting the spikes then yellow glued them into the bottom of each molded array disk.

Tried to roll light cardstock for connecting conduits but that proved way to thick. Ended up using plain computer paper and graphic paper for the various diameter conduits. Shown below was the first attempt with a 1/8" mandrel which is way too large for this model but I have something else planned for it in the near future;) other mandrels were a 5/32" bamboo stick, 1/16" dowel and .052" stainless MMX launch rod....talk about cramping the fingers LOL!!!

1/32" balsa standoffs complete the base array assemblies. They are yellow glued in place on both open faces of the models BT-20 body. Once dry, both got a very thin epoxy fillet to smooth out any small glue gaps.

On to the other details and add-ons. If everthing goes well with the other surface details I may be able to get a primer coat on it sometime this week?

MM 370uc14a_Antenna Arrays, Dish & piping_06-25-10.JPG

MM 370uc14b_Both Antenna Array's attached_06-27-10.JPG
 
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Decided the 1/16" pipe would look about right so suspended cramping my fingers rolling with the 052" wire. Ok it was easier.... rolled about a dozen pieces trying to get the wall thickness down but they always seems to need about 3 wraps to give a good stiffness when dry. Only let them dry for about an hour before cutting off an end to miter in a 90° corner. flipped it over an repostioned with tweezers and a toothpick while adding a dab of yellow glue.

I think the second worked better but I forgot to take a pic of it before gluing it on the model.

MM 370uc15a_Rolled paper piping mitred_06-28-10.JPG

MM 370uc15b_1st pipe attached_06-28-10.JPG
 
To make the round tube hatches I want back to the 3/16" paper tubes already rolled. I think they are a tad large but they are already made, making the bulkhead doors was a matter of CAing to 1/8" long pieces to some cardstock. a little work with a sharp #11 and a bit of sanding will work them proper fit in short order.

Making a bridge jumper from a half piece of 3/16" long T2+ that should complete the major external parts.

OH! you guys may be wondering what the FS model looks like. The Last 2 pics are big brother on the pad and at liftoff on its shakedown flight Saturday the 19th.

MM 370uc16a_twin tiny tube hatches_06-28-10.JPG

MM 370uc16b1_Bridge & hatch attached_06-28-10.JPG

MM 370uc16b2_Bridge & hatch LLside_06-28-10.JPG

481-Lp01c_KBK-10 on .25in rod hooked up & ready_06-19-10.jpg

481-Lp01f_KBK-10 Ignition & liftoff on Nice 1st flight_06-19-10.JPG
 
John is there an alternative motor geometry for a 6 engine cluster? I'm interested in finding the most efficient way to fit 6 18MM BP engines in a single body tube.
Joe,

Go to Doug Sams's website: https://www.doug79.com/DougsRockets/

Click on the links "Cluster patterns for BT-55 to BT-70" and "Cluster patterns for BT-80's" to see what motors will fit in what size body tube.
 
Did a little more work on the Cosmic Cluster over the last couple nights, mostly filling and sanding, smoothing gaps with CA or white glue. ALL the little Pieces are a pain to sand around LOL!!
I'm going to give it a first coat of Primer either tonight or tomorrow depending of one last little joint filling issue.
sorry no new pics at this point, just the boring sanding/filling parts:)
 
work continues on the model, Primer sanding is going a bit slower then expected, all this humidity is causing drying times to be really extended. I not in a super hurry on this one anyway as I'm waiting for some new supplies to come in to finish both the full size and micro versions.
 
To make the round tube hatches I want back to the 3/16" paper tubes already rolled. I think they are a tad large but they are already made, making the bulkhead doors was a matter of CAing to 1/8" long pieces to some cardstock. a little work with a sharp #11 and a bit of sanding will work them proper fit in short order.

Making a bridge jumper from a half piece of 3/16" long T2+ that should complete the major external parts.

OH! you guys may be wondering what the FS model looks like. The Last 2 pics are big brother on the pad and at liftoff on its shakedown flight Saturday the 19th.
Sure is a lot pieces parts going into /onto
that bugger.Looks wicked good Micro. Scotty Dog
 
Been kinda busy with family and ROMC duties the last couple weeks. Did do some priming, sanding and basecoating on the Cosmic Cluster and took a couple pics of the progress.
I'm really having trouble deciding on final color combinations. As a deep Space research vessel we're looking at a very new combinations of Silvers, Stainless Steel, Titanium, Reds, Blues and maybe some copper? Decals will be mostly Black and a lighter Grey or light silver.

MM 370uc17a_ready for 1st primer_07-03-10.JPG

MM 370uc17b_with upper section FS ready for primer_07-03-10.JPG

MM 370uc18a_1st primer coats_07-03-10.JPG

MM 370uc18b_Primed model after sanding_08-29-10.JPG

MM 370uc19a_1st basecoat Metallic Silver_08-29-10.JPG
 
Looking good, John! I like those silver-ish photos at the end. Maybe with some red for detailing?

Will you use "no eject" motors in the outboards or let the empty casings fly?
 
Looking good, John! I like those silver-ish photos at the end. Maybe with some red for detailing?

Will you use "no eject" motors in the outboards or let the empty casings fly?

That's a roger Will: 4 MMX-II's in the core and 2 MMX-II-NE's in the outboards. Should be a very quick launch, She is going to be a Piggy so I'm not really expecting all the much altitude but she'll get there is a big hurry :)
 
Got a step closer to finishing this bird. putting the Blue Anodized finish over the Silver base coat. Printed the Decals. Now all I have to do is make myself sit down and do the Detail painting before the decals can be applied.
It's awful when ya just can't get motivated...

MM 370uc20b_MM Cosmic Cluster Anodized Blue_10-10-10.JPG

MM 370uc21a_MM Cosmic Cluster Decals printed_10-10-10.JPG
 
getting very close to complete now.
This has been one of those long projects stuffed between a couple other things.
Over the weekend I made some time to cut out and apply the series of decals and hand painted detailing needed to pretty much complete this Rocket.
All she needs now is a tiny bit of touch up on a goof I made. and a coat of Future to complete the decal process.
This has been a very interesting build. I learned a couple things with this one.

With any luck at all I'm hoping to fly it at the Nov. 20th Sport launch..We'll have to see as the Theme for the month is Gliders? Gliders OH Man I'm awful with gliders...

MM 381uc22b_Antenna detal Paint & color_10-31-10.jpg

MM 381uc23a_Forward Pod Decals complete_11-06-10.JPG

MM 381uc23b_canopy & name decals_11-07-10.JPG

MM 381uc23c_lower section, & Fin Decals & paint_11-07-10.JPG

MM 381uc23d_Need Future to be Complete_11-07-10.JPG
 
gotta be the longest Micro model build in the fleet. finished adding all the Noseweight and making the 12" x 1/2mil mylar chute over the weekend. Hope to get her in the air again this weekend. We'll see the sport launch theme is gliders.

last few Static pics..I hope.

PS: Didn't get to launch her over the weekend, the Better 2/3rd had a bit of a Knee issue so we didn't attend the launch. DEE RATS better luck next month.

MM 370uc24_Nose seperation touchup_11-07-10.JPG

MM 370uc25_8.3g Nose weight added_11-13-10.JPG

MM 370uc26_Cosmic Cluster Complete_11-14-10.JPG
 
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The Cosmic Cluster is now almost 6year old. During that time it has only had two flights, the first a two motor and the second a 4motor.
but as usual I was unable to catch a photo of the model.

Last Saturday I had another chance to fly the Cosmic Cluster on 4 motors and had the good luck of catching it in mid flight.
Was and absolutely perfect flying deploying a competition style 1/4mil 12" mylar chute about about 40 feet. I'll add the photos a little later as soon as I adjust the orientation.

LP03a_Cosmic Cluster 4motor Relay ready_11-15-14.jpg

Lp03b_Cosmic Cluster 4motor mid Flight_11-15-14.jpg
 
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