Making the SR-71 (Flymodel)

Discussion in 'Aircraft & Aviation' started by Mindaugas, Mar 25, 2005.

  1. jasco

    jasco Member

    Just catching up on your build. It looks fabulous and I think you have quite a sense of humor. I especially like the horse on the chopper.
    In order to join the segments together are you fitting the formers flush to the edge of the skins and then gluing them together? I also don't understand the rounding of the edges of the skins with glue. Won't that prevent the pieces from fitting tightly to each other?
    Here in the Chicago area, we got about 6" of heavy, wet snow dumped on us two weeks ago. Temps hover around freezing with some sunny days and some cloudy ones. I dislike the winters around here. Someday I will retire to Arizona. The only good thing about winter is that it gives you plenty of time indoors to build models!
  2. Mindaugas

    Mindaugas Member

    Hello dear jasco,

    Thank you for the praise. You can't imagine, how happy this makes me.

    And answers. I put flush formers together and then I sand them, in order to make them identical. Then I put each into its skin section, then I paint edges, and then I connect those sections together.

    And yes, you're right. There won't be good fit with rounded edges. But.. in my case, this is an open-ended exaust tube. So I had to round its edge, to make it look better.

    And why don't you like winter? I like skiing and other winter sports. It is really interesting. Once in my village we had about 5' of snow. Corridors were made in order to get around :D - Kasserine pass :twisted:

    Thats all. Good luck! ;)
  3. Ashrunner

    Ashrunner Member


    43rd Bomb Group explains it then. The Dragon and its Tail was also a 43rd BG bird, from the 64th Bomb Squadron. Before the Collins Foundation repainted their version of the B-24, I saw it twice and got some nice photos of it. The tail markings were what told me it could have been that aircraft.

    Also, were you looking for a lit cockpit image of the SR-71 cockpit? A friend of mine has a book with a photo of the front cockpit taken at night. He says it isn't a great angle shot, but shows what it looked like. If I can get him to scan the image, I'll forward it to you if you still need it or want it.
  4. jasco

    jasco Member

    Mindaugas- Thanks for the explanation about the rounded edges. I've never tried the flush formers method. I've always used joining tabs between two skin segments and then put one former in wherever it fits.
    I don't like winter because I am a runner, and I'm too old to tolerate too much discomfort! Not enough snow and certainly no hills to ski on. This is very flat land. This time of year tends to be full of grey, drizzly, wet days that makes outside activities unpleasant. Not to mention that it doesn't get very warm until June.
  5. Mindaugas

    Mindaugas Member

    Helo Friends!

    Ashrunner - thank you for comments.
    Jasco - thank you for comments also. Well, I also sport and before every workout session I run several kilometers. It is not very pleasant to run on slippery (or rough) surface when it is -25 and the nose hair sticks to each other, when you breath, but it is a good training for the spring - when the running surface and weather will be excellent!
    Also most of my models are made with flush formers. I haven't tried that "joining strip" method much, but I see that "joining strip" method is getting more popular (see the newest A.Halinski models!). ;)

    A small update. I've begun work on intake areas and finished the exausts.

    In one photo on internet I noticed, that SR-71's exausts have somekind of openable panels. And I've noticed those panels painted on my paper exausts. So I cut them out:


    And painted:


    Here are the roots of the engine intake cones.

  6. Mindaugas

    Mindaugas Member

    And. I want tell you about seam filling. I've used my own way of filling. I use dilluted white glue for filling. When I apply glue, I take off the excess with paper tissue. Procedure must be repeated 5-6 times, because glue sack in very much. You repeat until the seam is gone. Dont' worry, white glue cures really fast. Then you just paint over it with the same colour. I didn't use any masking tapes, so, relatively large area was covered. I suggest to use masking tapes to work just in a small area. In order not to spoil surrounding areas.

    Also you should try using super glue (cyanoacrilato glue). Some plastic modelers use it as putty. The main advantage is, that it doesn't sack in.

    Also look for glossiness. In my case it differs from paper glossiness. But if you varnish all the model after it is finished, it doesn't make sense. Remember, that varnishing complete model is useful in many cases. It is really important step of model making.

    So the work process of seam filling. I should note, that the nearby seam is awful, because I haven't even connected these segments.




    Now, my friend Donatas told me some interesting information as well. Firstly he uses special nitro-paint. We call them like that in Lithuania. I don't know how you call them in your countries. I don't know any alternatives to this name. He has just basic colours - Red, Yellow and Blue. Plus black and white colors for shading. He mixes those colors untill proper one is attained. There's a tutorial on how to mix colors properly on Tutorial is made by Syzyf. Its main idea is to scan the model, determine the amount of basic colors in that model color using Adobe Photoshop, and then, using that proportion - mix them.

    So Donatas suggests to use these nitro-paints. They are really stiff, so they can be used like putty. After paint cured, he scrapes them with blade. The surface becomes ideally smooth. If you want better result, you can also coat another layer of paint (with paintbrush or airbrush - then you need to dillute them). And he said, that nitro-paint preserves paper facture. Contrarily nor hobby paints.

    So you should choose the best variant for yourself. There are really many ways to fill those seams.

    Thats all. Good luck! ;)
  7. Ashrunner

    Ashrunner Member


    The panels you refer to are those which allow air into the AB chamber. They were more of a ramp to guide the air, as seen in this photo of the rear engine section of one of the YF-12s. Like the SR-71, it was based on the A-12 airframe and has the same basic design structure.

    Attached Files:

  8. Mindaugas

    Mindaugas Member

    Hello everybody,

    Ashrunner, thanks for the explanation ;)

    I would like to announce, that there won't be any updates next week, because I am on my skiing holiday in Slovakia.
    Good luck! ;)
  9. Mindaugas

    Mindaugas Member

    Hello guys,

    I've been busy lately. School, sports and other things disturb me and I can't model.

    Also the journey home from Slovakia wasn't very lucky. I've been in accident. Our bus crashed.

    [​IMG] [​IMG] [​IMG]

    In the small village it drove into the turn on a slippery road and suddenly one car overtook us and stopped because some cars were turning left (they were letting by several opposite drivers). Our bus driver started to break, but he saw that he won't make it. So the choise was - stopped cars or the trench. Driver thought, that he would slip pass those cars on the roadside, but the roadside was too narrow. But the worst thing, that there was a concrete bridge across the trench to houses. So driver expected to slip pass the bridge and then to fall into trench, but the bus slided into the trench before the bridge. Bus crashed into the bridge and all bus front was pushed till the stairs into passengers salon. The resting (the one who sit on the left side) driver tried to jump into salon, but his legs were caught. One leg was broken in two places (one open break), thights were slashed and one rib was broken. If he hadn't jumped up, so the hips might got broken. So it is better than broken hips...

    Passengers were not hurt. Just some minor wounds, hurts and other sundries. I was just scraped in several places.

    But I want to say a very big THANKS for all people of Poland. You are the best! If you read my topic I want to express my biggest thanks for you!!!

    People, whose bridge was, quickly brought tea, wraps and let us inside.

    The rescue workers arrived in several minutes. They quickly evacuated all people and freed the trapped driver. People that complained about their health were taken to hospital.

    Then they took us to their station-house, gave us food and everything we needed. As we waited for other bus they've been with us and when we got in another bus, they even thanked us for such a nice time spent togeher. But wait! We are the ones that must thank those polish men!

    By the way. These rescue workers are called "Straz" in polish language.

    Polish people left me the best impression they could!

    Oh, and I had much more serious wound in the "Freeride Zone". I've pulled the straps of my left knee.
    This is a man from our group on that zone where we rode.


    Some photos of climbing to the south side (no lifts are lifting to the peak, so people must go on foot)
    Also we found ourselves in a very difficult situation - a cloud, where visibility is about 8 meters. But this was the most fun part of holiday!


    When we were returning, the cloud descended:


    Thats all. Good luck! ;)
  10. Mindaugas

    Mindaugas Member

    Ok, back to model!

    I've made the air intakes. Someone from german forum said, that intakes were a really bad nightmare, but I had worse spots. The worst thing that awaits is the skinning of the are between engines - the back of the plane..

    So, from the beginning. The intake is not very well designed. It is closed! That black disc should be a little deeper! But model is designed so.. and in order to change this, the intake should be redesigned at the beggining of building the engine frame. Lets say, the exaust tubes are deeper and they look better than those frontal intakes. The air intakes look like covered with some kind of plates (like the red plates, that are used to cover parked SR-71s). Another problem - the contraction on the right. It didn't met in one point. Look at the photo of the real intake. The tube of air intake is separate and the contraction occurs outside the tube. The contraction mets in one point.


    So when I finished it, I got and ugly gap. I've filled it with tissue dipped in white glue and then I filled it fully with several covers of dilluted glue. Overall it is not so bad, but there I have a small flat area that is athwart to the flight path - air resistance!! It is not like in real model... But in this place much work is needed and the results are unknown. So I will leave it as it is. But I want to warn others, who are going to build this model, to examine and make changes for those tricky places. This place needs to be redesigned from the beginning. I would suggest not to make the outer parts that contract, but to make separate intake tube with inside and outside parts and then to attach that contracting tip to the side of the tube. One more thing that goes together with those problems - the inner tube was deformed a little bit. It should be perfectly round (like in photo of real plane), but it is a little bit deformed. But this is a minor problem. Another problem is, that outer parts do not fit perfectly with inner tube. I tried to make the inner tube to protrude, because then I can trim it according to the outer parts. If inner tube was deeper and outer parts were protruding, so then all the trimming would have made all the intake area totally spoilt. And lastly I've put some dilluted glue on the edges in order to make them round. Later I am going to paint all those white areas.


    Next - tail. I've engraved panel lines with empty ballpointpen and ruler. This was made on my soft exercise book (the softer surface is - the deeper and sharper panels lines are, the harder surface is - vice versa). Also I've laminated the tail on double layer of whatman in order to make the tail really hard. Also I did one interesting thing. I've learnet the configuration of the tail and rudder on SR-71. And... it seems that the rudder in SR-71 is not like in classic planes (when the rudder is on the end of the tail). Whole tail above the lower line is a moveable surface (rudder)! So I cut out the rudder and painted edges in black. Then I painted that whatman for lamination in black also (in order not to see white colour underneath). And then I attached those tail parts leaving a small gap between them. Now the rudder looks like it is a separate part from tail.

    This technique is great, when separate aerodynamic surfaces are not designed on the model (lets say, A.Halinski designs separate surfaces, so there's no need to do this). Another - easier but not so impressive way is to engrave lines, between those surfaces, using very soft surface and ballpointpen. Soft surface is needed to get very deep panel lines. Also there's a way to change the whole designing of those surfaces, but then paper of the same colour is needed, there's much work when doing pivots, redesigning frameworks and the result might seem not so good...


    Some additional frame parts were added - to get extra tightness and precision:


    And finished exaust tubes:


    Thats all. Good luck! ;)

    P.S. Thank you for allowing to post unlimited number of pictures in one post! :wink:

    :twisted: :twisted:
  11. Gil

    Gil Active Member


    Glad that you survived the ski holiday...,

  12. jch_2004

    jch_2004 New Member

    can anybody send me draws of SR 71?
    in Georgia I can not bout it

  13. Amazyah

    Amazyah Senior Member

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