Dragon 144th Scale PMC SR-71A BlackBird 3motor cluster conversion.

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Micromeister

Micro Craftman/ClusterNut
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Last Night I has a few minutes to do some beginning work on my next Micro PMC. I've had a Dragon 1:144th Scale SR-71A plastic model in since early summer but have just been tied up with other projects.

Opening the box the model is exquisitely produced and large enough to easily be converted into a 3 motor Micro Maxx Cluster. I'm still debating weather to try ducting the Outboards into the main but that process May be possible. Even if we decide not to the model has plenty of room for making minimum outboard booster pods and might be large enough to allow a T3 or T4 internal body tube with a rear ejection motor pod with streamer or small chute.

I'll have to do a bit of Aft body surgery to seat the main body tube but well be fairly easy to accomplish.
As with Estes SR-71 I'll be adding to ventral fins to the model. I've been toying with the idea of using clear Lexan for these or simply doing what was done on the commercial model which looks just fine.

I'm hoping to grind out a good bit on the interior styrene to get a little of the mass down. As it sits taped up with minimum internal mod-roc parts she's almost 28grams (1oz). Add Paint, recovery and 3 motors we will be looking at around 35-40grams.

Looks like a nice PMC project, Hope I can get is going over the holidays.

SR-71A BlackBird_144th Scale Dragon #4639 PMC_12-10-14.JPG

MM 4xxuc01b_MM SR-71A BlackBird PMC Instructions.jpg

MM 4xxuc01c_MM SR-71A Blackbird 144th Decal Sheet_11-22-14.jpg

MM 4xxuc01d1_MM SR-71A Blackbird 144th PMC Taped Up components_12-13-14.jpg

MM 4xxuc01d2_MM SR-71A Blackbird Taped Up PMC_11-22-14.JPG
 
Too bad you can't find a D-21 drone to mount on it then the 3rd engine would be a snap then all motors could go in the pods. I may have to get me one in a larger scale, unless I can find an Estes SR-71. Looks like a cool project, have fun with it.
 
Too bad you can't find a D-21 drone to mount on it then the 3rd engine would be a snap then all motors could go in the pods. I may have to get me one in a larger scale, unless I can find an Estes SR-71. Looks like a cool project, have fun with it.

Estes SR-71 is a Hoot as a 3 motor Cluster! I'm actually working on my 4th models since they were introduced. Which is where I found that ducting the boosters into the main body is a very nice back-up should the core motor not ignite which is how I lost my original Cluster conversion.

On This little PMC ducting may not be practical as there is very little room inside the wings between the Booster motor pods and the Main. Last night I was looking at where I want terminate the aft end core bodytube which will determine weather this model will be a rear ejection pod or wil have a seperation up behind the cockpit canopies.
May not have any more time to mess with this model until after the Holidays. Things are getting busy Ho Ho Ho!:)
 
Off topic... If you ever decide to try superdetailing a Testors/Italeri 1/48th scale SR-71 or YF-12A, you'll have a lot of work cut out for you. Those expansion grooves cut all over the surface of the wings (between the engine nacelles and the fuselage), are GROSSLY overscale. If you scaled the Testors kit up, they'd be several inches deep. Upon finally getting a chance to examine tail number 61-7971 in close detail, those expansion grooves are maybe 1/4" (at most) deep on the real plane. I suspect for an accurate representation, one would need to fill in the grooves completely, then mask them, prime the model, then remove the masks and prime it again then put your finish coats on, they're that thin.


The ribbing is very subtle... VERY subtle...
 
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I must say your post is WAY off topic having Nothing at all to do with this thread or even this MMX forum.

Do you just post stuff to up your thread count? Sorry: don't intend to be mean but man...talk about off topic.

We're talking about 144th scale where a 1/4" expansion joint would be less then .0001" they would be all but impossible to precieve let alone scribe.

Not sure if you have ever done any kind of "Super Detailing" for PMC events but even 1:48th scale re-engraving micro joint lines would be a real challange, prehaps possible for a static model but totally rediculous for a flying PMC regardless of scale. That kind of Super Detailing isn't even done a Naram Quailty 1:32 Scale PMC entries of which there have been Several Clustered SR-71 PMCs over the last few years.

More then happy to discuss possible detailing and techniques for use on Micro PMC models here but lets try to keep the discussion in the proper Context and Scale;)
 
Hi John,

I was just trying to share something I had observed about the aircraft. Wasn't trying to hijack the thread.

All the Best!
Jim
 
While I'm Layed up after surgery I'm not supposed to be picking up anything heavier then 10lbs. So while I can't really do much:( I can proceed with a couple builds.

The Dragon 1/144th SR-71A Blackbird is a much bigger model then I envisioned when I purchased the model last December.
Like my Estes SR-71 this build was intended from the start to be a 3 motor Micro Cluster but I have to admit this one is going to be on the heavy side.

Up to now you guys have seen the taped up main components. below you'll see a couple pics of the cardboard cut-out of with 1 and 1-1/4 caliber CG location based on the LCP. after again adding all the components and internal material I went the 1 caliber location as that Still adds 11.4g of mass to this already heavy model. Because she is tipping at scale at 46.7g unpainted I'm going to add only one coat of Gloss Black to the model Decal it, then single coat with Krylon UV resistant Matte clear. Hopefully this will allow the completed model to stay under 50g.
Recovery will be by 8" dry cleaner bag chute connected to the 36"- 70lb Kevlar shock-line and 49streand stainless beading wire Shock-line anchor.

After much thought I decided to vent the 1/8A.5-1-NE boosters out the rear of the model by encasing the T2+ motor tubes in a T3 outer shell centered with T3 groved rings and slotted plastic motor parts. The forward end of the booster T3 Tubes are sealed with a Balsa block epoxy coated over two layer of Stainless steel tape on the inside burn through surface. I believe the 4 slots should give plenty of room for venting the gas generated keeping the friction fit motor casings in place.
Below are the first 8 photos during this build. More to come a little later.

MM 408uc02a_144th SR-71A Cardboard Cutout_02-19-15.jpg

MM 408uc02b_144th SR-71A Cut-Out & Model_03-01-15.jpg

MM 408uc03_144th SR-71 Routed & Sawn Motor Tube Openings_02-20-15.jpg

MM 408uc04_144th SR-71 Nose Section Sawn_02-20-15.jpg

MM 408uc05a_Dry Fit T3-T2 Main Body &  Outboards_02-21-15.JPG

MM 408uc05b_Dry FitT3-T2 Main Tube Close_03-21-15.jpg

MM 408uc05c_Dry Fit Outboard Booster T2-T3 Tubes_02-21-15.JPG

MM 408uc06a_St.Stl Beading wire Shockline Mount_02-22-15.jpg

MM 408uc06b_Main MMT & ShockCordAnchor Ready for installation_02-22-15.JPG

MM 408uc07_Booster T2-T3 MMT inserts_02-28-15.JPG
 
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over the last couple days this build has progressed.
Starting with epoxy installing all three motor mount/bodytube sub-assemblies. Since the Cockpit interior is visible I hand painted the seats and tub and flat black painted the interior surfaces.
First though was to use a balsa block as the nosecone shoulder but then realized I needed a way to house the 11.4g of # lead shot nose weight. so I used a section of T3 tubing and made a custom internal coupling/shoulder from another sections of T3 tubing. Threaded between these two tubes to the inside of the shoulder was white Glued a 70lb kevlar shock-line attachment loop. Once the shoulder was completely dry it was epoxy installed in the Nose section and all the main body and nose parts were Solvent welded and Epoxy joined.
With all the internals done completing the remaining external Styrene parts Upper rudders, Intake cones and custom cut bottom styrene fins was a breeze. Last touch was to split a micro Launch Lug into two small pieces, CA & Epoxy them in place and add small Epoxy fillets to all four fins.
The model is now ready for a single coat of Gloss black once I can get down in the Rocket Dungeon to my spray booths.

Now I'll move on to either my Flis Bumper Wac model or work on a previously started 1/144th F-22A Raptor PMC. The Raptor will be another Micro two motor cluster.

MM 408uc08_Main & Booster Tubes Epoxy Installed_03-01-15.JPG

MM 408uc09_Pre-Paint Cockpit and Nose_03-01-15.JPG

MM 408uc10a_T3 Nose& Shoulder with loop_03-01-15.JPG

MM 408uc10b_Main Body & NC should Epoxy installed_03-01-15.jpg

MM 408uc11a_Intake cones & Upper fins(Top)_03-03-15.jpg

MM 408uc11b_Custom Styrene lower fins(Bottom)_03-03-15.JPG

MM 408uc12_Fin Fillets & Launch Lugs(Bottom)_03-04-15.JPG
 
The SR-71A Blackbird is coming along just fine.
Now Painted with 2 coats of Gloss black. The clear canopies have been installed. Now ready for Decals. Then a coat of Matte Clear.

MM 408uc13a_144th SR-71A_Painted Black Canopies On_03-21-14.JPG

MM 408uc13b_144th SR-71A_Painted Black Bottom_03-21-15.jpg
 
Happy to report the SR-71A Blackbird 144th 3motor Cluster is now complete.
Dragon made some very nice Itallian silkscreened decals but their Clear Coat is pretty thin & Tiny. I decided to give the sheet a coat of Krylon 1305 Gloss UV clear prior to cutting and dipping. All when on as desired using Microscale Micro-Sol solution. give them overnight to completely sit and dry then mask the clear canopies and gave the entire bird a wet coat of Krylon 1309 Matte UV resistant Clear. I'm quite happy with the end result.

For a micro model (even a 3-motor cluster) this PMC is on the large side Diameter: .5163" x .953", OA Length: 8.5625", Wing Span: 4.5625".
Ewt: without 10" chute 48.6g. Complete: 03-25-15

MM 408uc14_144th SR-71A BlackBirdA_Fully Decaled_03-26-15.jpg

MM 408uc15_144th SR-71A BlackBird_Matte Cl. Coated & Complete_03-28-15.jpg
 
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Sweet conversion. That is an awesome plane, perhaps my favorite.

Don
 
Static Fleet Photo with stats;
Last photo before flying this one, Like TopRamen I sure hope I can catch a couple good 3 motor liftoff shots of this one;) Will certainly give it the old try.
She's Heavy but with a MMX-II and 2- MMX-II-NE motors she should still get decent PMC altitude. Was very happy to be able to get a 10" rather then 8" drycleaner bag Chute in the T3 bodytube with a 1/2" x 5" piece of PTFE teflon premanent wadding to protect it from the heat.
After talc baby powdering it should be slick enough to eject smoothly. That's the plan anyway LOL!

MM 408a_SR-71A BlackBird 144th Dragon PMC(30.12)_03-25-15.jpg
 
Hi Micro,
Maybe for your next build, mod the kit to the YF-12A config? Gives you a bunch of extra ventral fins and should help the lateral-directional stability....a lot
Also makes for a good trivia conversation starter

ap-usa-SR71 Blackbird-00015-YF12A w vntrl fin deployed-imagesdotklassiker-der-luftfahrt-ueberflu.jpg
 
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Hi Micro,
Maybe for your next build, mod the kit to the YF-12A config? Gives you a bunch of extra ventral fins and should help the lateral-directional stability....a lot
Also makes for a good trivia conversation starter

Actually Powderburner I added a pair of Ventral fins on this SR-71A for just that reason. Guess they didn't show up well in the photos.

MM 408uc11b_Custom Styrene lower Ventral fins(Bottom)_03-03-15.JPG
 
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