Micro-Maxx Lockheed x7A with Booster Ram-jet Test bed vehicle. 1:81.300 Scale

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Micro Craftman/ClusterNut
TRF Supporter
Jan 18, 2009
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Washington DC
While waiting for Tiamat primer 1st 3 coatings to cure, I'll return to work on a model that has been in the beginning stages since 2003.

Lockheed x7A Ram-Jet test bed vehicle with large Booster. This scale model has been in my build que since feburary of 2003.
I completed the 8.5" x 14" McCoys' Micro Wonder Works drawing July 7, 2003.

Deciding on what size this model should end up being more of a problem than invisioned. I wanted to try to stage this model but the offset adaptor transition just made that option hightly unlikely. I decided to simplify the offset transition just a little making the offset slightly straighter and then decided that T3 (.375") Booster body tube would be my starting point, translated to scale that gave me a 1: 81.3 scale with a miltiplier of .0123.
Once the drawings were at least in usable shape the actual "Hard Part" of turning the scale ramjet, transition and nosecone began Aug. 20, 2003. The actual x-7A turned out to be T2 (.246"od) so there is no way it will ever be flown without a booster. I also noted the nose probe would be far to fragile to be made out of wood or plastic so. the drawing as labled for this part to be turned from 1/16" brass rod. with a 3/8" insertable aft end. The hope is it's mass will help limit the amount of nose-weight required to make the combined x-7A & Booster stable. I'm still looking at cardboard cutouts and a rought roc-sim approximation for a Cp-CG relations.

Once these paliminary steps were done I turned the basswood parts and then set the project aside until June 29th of this year. I still really wanted to find a way to stage this bad boy but without completely starting over from scratch using a much larger scale it just wasn't going to happen.

Over the last couple months while working on other projects, I dug a little deeper into the history for this Lockheed project and found a couple color photos that had eluded me during the hunt.. Now I knew what the basic color scheme would be over the old black & white photos that had stirred the interest orginally. My model would be based on the 06-20-1960 Lockheed test flight prototype.

So here we go: Working from pieces of the draft MMWW scale drawing our parts were sized & shaped using file folder patterns to transfer score lines and details to the .020" & .030" white styrene used for both x-7A and Booster Wings, Tails, & Elevators. orignially the ramjet pylon was also cut from .030" styrene but after a bit more research found this was far too thin, The pylon now started as 1/16" basswood sanded to shape and profile.
Again this model was set aside while I concentrated on the Tiamat scale construction.
so another couple months passed before I could get back to actually mounting any of these styrene parts. One thing I have come to understand. When working with styrene to cardboard joints on this scale the adhesive for the job is Medium CA. and you really need a very good dead flat fin alignment jig to get everything aligned.

Even using my Aluminuim fin alignment jig I had to break off and re-install the vertical tail on the x-7A. We have completed the x-7A construction. added extra lenght to the Booster Adaptor transition and have the MMX Motor mount, 30" - 70lb Shockline and 1/4" x 9" yellow teflon streamer complete and installed.

All that remains will be mounting the very large area Booster Wing/fins and Vertical tail.
Our booster vertical tail is no problem at all, the Booster wings however are offset the hight of the Ramjet pylon, a bit over 9/64".
This offset will have to be shimmed off center much like we did with the x-7A horizontal stabilizers. arranging this shim build up is the hold up for this final construction piece.

Below are a few pics of where we are so far.

MM 421uc01a_Lockheed X7-A 3-view Dwg_07-23-03.jpg

MM 421uc02a_Lockheed X-7A Patterns & Styrene Parts_06-14-16.jpg

MM 421uc02b_X-7A T2, T2+, T3 & Turned Basswood Parts_06-14-16.jpg

MM 421uc03a_X7A Styrene-T2, Wing Assembly begin_08-24-16.JPG

MM 421uc03b_X7A Tail re-positioned_08-24-16.JPG

MM 421uc03c_Hor. Stab elevators, shim installed_08-24-16.jpg

MM 421uc03d_Hor.Stab MC reinforced_08-24-16.JPG

MM 421uc04a_X7A, Ramjet & Booster body fit Up_08-24-16.JPG

MM 421uc04b_X7A Turned Basswood Ramjet installed_08-24-16.jpg

MM 421uc05a_X7A, Adaptor,Ramjet,T3 Booster body & recovery_08-25-16.jpg
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Last evening I had time to gather up enough alum shim stock to make up the 9/64" offset for the Booster wings. Got my Fin alignment jig out again to make sure these huge wing/fins are set at the proper location. Man how did we ever live without Spring Clip clamps;) Wings on the tail was more or less a snap. all three need epoxy fillets to complete the booster. Below are a couple photos or the progress so far.

Cardboard Cutout LCP & CG locations are in the works. Swing testing this combination is going to be a challenge LOL!

Once the fillets are on my next step will be to create all the little surface antenna blocks and tiny surface data points.

Since this Saturday is the Better 2/3rds Birthday and our 39th Anniversary Bash. doesn't look like I'll get any more done on this model until late Sunday afternoon or Monday. This Party is gonna be great, Lots of food, fun and a good amount of Bass Ale LOL!

Have a great weekend everybody!

MM 421uc06a_x-7A booster offset wing attachment_08-25-16.JPG

MM 421uc06b_x-7A booster offset wings & tail installed_08-25-16.JPG

MM 421uc07a_x-7A & Booster joined(SideView)_08-25-16.jpg

MM 421uc07b_x-7A & Booster (TopRear)_08-25-16.jpg
Another amazing build! Puts my craftsmanship to shame. :cheers:

With that nose probe, you could use it as a dart LOL

Very Cool. With that turned brass nose probe and too many Bass Ales you will have to resist glide testing it into the dart board at the pub:)

LOL! you guys! actually in my younger days I was a pretty good dart thrower, used to throw as the anchor in an Alexandria, VA. Dart league. Great fun! Oh and drinking while in the tournaments was all but requred LOL!

That said; You are both quite correct, The x-7A's long nose probe was not only used to transmit speed, distance & location data it also severed as a Ground penetrating landing probe to keep the vehicle standing straight up for easier recovery helping to miminize any damage to x-7 & Ramjet. I was quite amazed by several of the project photos with the X-7 standing straight up in the desert floor after test flights, below is one of the recovery photos. It's almost funny.
Found a second b&w landing shot of another flight, with some of the x-7A records.

Z_Lockheed X-7A-p01c_Under Boost & Chute Landing(Color)_06-20-60.jpg

Z_Lockheed X-7A-p01d_b&w After Chute Landing & Data_04-26-51.jpg
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Sunday evening it was time to check the LCP from our 2 view Cardboard Cut-outs and determine where our CG should be. After averaging the two individual LCP's our vehicle LCP is located 4.96875" (4-31/32") from the tip of the nose probe. using the booster and Ramjet diameters as the max diameter, 1 caliber stability put the CG dead center of the x-7A's vertical tail. Since I wanted to check this stability margin with a swing test I decided to go with 1.5 caliber moving the CG to the forward tip of the vertical tail/body joint, 4.34375" (4-11/32") from the tip of the nose probe.

1.5 Caliber CG location required the adding of 2.8g of nose weight. Using #9 lead shot that worked out to 56 pellets. about half of which fit nicely in the hollowed out Nose & long shoulder with the remaining housed in the Adaptor body extension tube inside the x-7A.

Swing tests with MMX-II (1/8A.5-1) motor in the booster were positive indoors and outside on an 8ft kevlar thread. Looks pretty good swinging around out that far.

Now my only slight headache is where to put the Launch lugs??? I wanted to use a Nanobeam 30cm rail with H-Beam lugs but there is just no good location to mount them. I'm thinking of adding a Fliskit tiny 1/4" long lug off center on the booster and a smaller 1/8" long or less on the same side of the ramjet pylon. I'm hoping they will not be too distracting from the finished look.

More to come: adding some tiny surface detail and multi antenna.

MM 421uc01b_2-view Cardboard Cut-Outs & Nose Wt._06-14-16.jpg
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Thanks Top! it is a KEWL looking combo!

Last couple days have been fun cutting, sizing and applying all the projection surface details on by the x-7A and the Booster. Most of these little antenna, charges and other projections have been simulated with .030" .063" & .080" round styrene rod, Half Round and Sheet CA or MC installed depending on the substrate to which they are being attached.

Located and CA/Epoxy installed two very small .051"dia. x 3/16" rear and 1/8" forward launch lugs. They are ugly but I have no choice. there just isn't a place to hide them. but we'll try to not draw attention to them after painting.

It's time to give this model it's first 3-coat application of cheapy auto primer. After some sanding I'll know if I filled the spiral seams well enough to Not need any more primer. This model will end up being Gloss Orange with matte black leading edges on the x-7A. Some of the projections will be matte black also. The booster I'm going to simulate is bright Yellow with just a little weathering to bring out the panel lines.

I've researched all the places I know without finding a CLEAR picture of any lettering or logos on the x-7 or Booster so I'm going with my best guess as to what may be there???
More to come as we sand, paint and decal.

MM 421uc08a_MM x-7A surface details done_08-30-16.jpg

MM 421uc08b_MM x-7A Booster surface detail_08-30-16.JPG

MM 421uc08c_MM x-7A & Booster surface details done_08-30-16.jpg

MM 421uc09_MM x-7A & Booster Primered_08-31-16.jpg
over the last few days I've made a small change in the .051" diameter launch lugs, reducing the length of both forward and aft to 1/16" long.
also worked some additional sanding 240 & 360grit of the primer, Late Thursday night a single White basecoat was sprayed on the entire model, giving it overnight to dry. Friday morning lightly 360 sanded the basecoat, Tac-Ragged and let the fresh surface rest a couple hours.

Friday afternoon the x-7A was masked, so I could paint the transition adaptor and booster section Sun Yellow. Allowing about 15minutes for the yellow to tac-up, remove the masking then allowing the yellow to dry for an hour. While I'm thinking about it, I've ment to tell you folks all the mis-matched paints being used on this model. The trick that allows me to do such "horid Mixing of manufacturers" is very simple. Test spraying a sample piece with the colors/manufacturers intended for use on scrap Body tube and/or plastic sheet. using the same procedure as I intend to use on the model. Same time frame and spraying pattern/speed.
If we get a bad reaction on the sample then we don't use it on a model. So far using this technique and ALWAYS spraying the very fine mist coat over dissimilar pervious coats i've had exceptionally few paint failures. The paints and primers used for this little model are: Primer is "Fresh N Easy" Wal-Mart grey auto primer. Primer allowed two days to outgas. Base coat white is old formula Krylon Gloss white, Yellow is Valspar sun yellow, Orange is Rustoleum "Home Group", Gloss black, Matte black, Titanium, Stainless Steel and Silver are all Testors brush bottle paints.

After allowing the Yellow an hour to harden enough to "handle", the transition adaptor was again masked along with the Ramjet & Pylon with Yellow "fresh surface"
Frog Tape. x-7A was then sprayed with Rustoleum Orange, allowed to tac or about 10 minutes and the masking removed and set aside to dry.

Over the next couple days most of the hand painted detailing will be done. Ramjet will get 4 color black,metallics and shade. Most of the raised details will be hand painted matte black along with all leading edges of the x-7A .
Below are the latest 3 progress photos.

MM 421uc10a_x-7A & Booster BaseCoat White_09-01-16.JPG

MM 421uc10b_x-7A & Booster basecoat white_09-02-16.JPG

MM 421uc11_x-7A in Orange, Booster in Yellow_09-03-16.JPG
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It's been a busy last week or so.
Actually haven't been building anything but did get a chance to quickly apply the hand painted surface details, run a set of Decals, get them applied and apply a quick coat of Pledge w/ Future.
Intended to launch this models maiden flight at the clubs annual Day/Night launch Sept. 17th but got wrapped up checking out perspective Night Flight model Lighting packages and battery locations/orientation to get ahead of any possible "Dark flights" due to poor or improper battery placements. Worked out pretty well as we only suffered a single Lights Out at ejection on a single flight.of 32 night flights flown. But I went the entire Day & Night launch without flying a single model LOL! Sometimes it's just good to be out on the field with friends.

Anyway; I haven't taken the Spec's Photos of my x-7A yet but the three pics below show the finished product.
I'm not very happy with the way the masking went on the leading edge surfaces but they will have to do as the next couple weeks are packed with all kinds of non-rocket related activities so we'll see when I can get back into building.

Thought since all this tiny surface detail was Hand painted in Flat black I would try the much touted Tamiya masking tape that i've heard so many people talking about on TRF using it without sealing with clear and getting great straight lines without wicking.
Well folks; that is pure BS! After taping and burnishing the masking down well on all surfaces the 6mm Tamiya tape wicked as badly or worse then any other tape I've ever used (not being clear coat sealed). I ended up trying to straighten out the crudy lines by hand lining with a brush. Leason LEARNED. Do not believe anyone who says you can prevent wicking with Tamiya or any other masking medium without applying a light sealing coat of Flat or Gloss clear coat before detail painting.

Have the AIR-2a Genie started but haven't made to much progress yet.

I'll add the Stat's photos of the x-7A when I get around to taking them.

MM 421uc12a_x-7A Surface Details complete_09-16-16.jpg

MM 421uc12b_x-7A TopView Surface Details_09-16-16.JPG

MM 421uc12c_x-7A SideView Surface Details_09-16-16.jpg
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