Yak-3 1:50 [build]

Discussion in 'Aircraft & Aviation' started by cygielski, Mar 17, 2005.

  1. cygielski

    cygielski Member

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    This is my build of a Yak-3, a 1:50 scale model by Marek Pacynski.

    I like Yaks. I think they are some of the sharpest-looking airplanes of WWII. I have had warm feelings for Yaks (stop me someone!) since I first put together a little model of a Yak-1 as a kid -- I must have been 10 at the time.

    Even before I started building it, I noticed a few problems:
    1. a complete lack of instructions (just two general views)
    2. two parts numbered 25

    [​IMG]

    3. an extra line on the ailerons (also shown is part 25 number 2) :)

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    Undeterred, I decided to step up to the plate, testing a few ideas in the process. The first was to use plain paper for joining strips, rather than cardstock. The idea was that since I was going to be converting the construction from a butt-joint system to the former-and-joining-strip method, the paper strips would require smaller alterations to the formers to make things fit. Unfortunately, despite the fact that I have read several positive opinions of this method, I can’t say it worked for me. I got an ugly joint, I think mostly because the paper didn’t give me enough support from within.

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    I did the remaining joints using cardstock strips, with much more satisfying effects.

    As I had some problems with lines on the fuselage not matching up properly (despite my valiant efforts), and also because the red of the insignia was a bit dull, I decided to “improve†the plane a bit, using my daughter’s watercolors and a pencil. I lost the cleanness of the original design, but I don’t like “soulless†computer-designed models anyway, so in the end I got an effect I think I like. Besides, how could I not like those nice bright-red stars? :lol:

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    Here’s a comparison of the colors before and after:

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    Here’s my Yak’s belly. It’s not as bad as it could have been -- those of you who have have monitors set to about 1200x800 resolution can see it just about life size on the photo when you bring it up full size. (I have already retouched the white bit around the rear wheel, so no need to point that out) :mrgreen:

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    Here’s a front view of the stabilizers -- I’m not too happy with them, but they seem to be relatively symmetrical.

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    I have also started working on the propeller. Below is the first segment of the spinner.

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    Right, that’s about it. Any comments would be welcome.
  2. Gil

    Gil Active Member

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    Yak, Yak, Yak..., That's all Cigieski talks about. Next thing you know he'll be on to Migs and then it will be Migs, Migs, Migs...,

    Glad to see the build report. The section joiner system style of construction takes some time to get used to especially if you've been "stacking" the fuselage sections. I've found that you have to pay close attention to precise seam cuts and prepare them by lightly sanding them smooth with 400 grit sandpaper on a glass pane. Preparing the seam with a light inside coat of lacquer also helps to stiffen and vastly improves the sandability of the paper. Another point is the type of glue being used. The section joiner system works better for me with white glue as it gives enough time to "work" the seam against a cork pad with a burnishing tool. This helps "blend" the seams together. I'm not sure that using card stock for the joiners is a good idea as it will tend to show through the paper on either side of the seam after burnishing. Of course a light touch with the burnishing tool and being careful to apply it only over the immediate seam area reduces this effect. One last item is that I've found 100% cotton bond paper (24-32#) to be best for joiner strips.

    Hope your seams appear seamless...,

    Gil
  3. cmdrted

    cmdrted Active Member

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    Cigielski, The Yak looks pretty good, with Marek designs, esp converting them to strip methods all that Gil has said applies, also I found that if you "preform" the fuselage sections to the shape of the bulkhead that is supposed to be at the ends of the section, and extend that form along the length of the section it goes better. It is easier to have the bulkhead gently ease the fuselage section into its final shape than having to squish the ends to fit the former. sounds complicated but see pics, Ted
  4. cygielski

    cygielski Member

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    Have you posted anything about this method of 'working seams'? If not, could you elaborate?

    This is not a problem - I trim down the formers by the thickness of the cardstock (maybe that's a bad word, suggesting index card-type material -- I'm using the card that the model is printed on, which is actually relatively thin). the joining strip actually supports the joint from underneath, providing a slightly wider base than just the former alone.

    Here's a rough sketch of what I mean (in cross-section):
  5. cygielski

    cygielski Member

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    From the above, it's easy to see that the flabbier the connecting strip, the less support the end of the "open" section gets. Of course the pre-forming is a given -- you can't expect the formers to do all the work for you.
  6. Gil

    Gil Active Member

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    No, I haven't posted anything that I remember maybe a little clarification will help. Assume the joiner strip is in one of the formed sections. White glue is then spread uniformly in the next formed section. The section with the joiner strip is then inserted firmly until the two sections butt joint is aligned and comes closed. The joiner strip between the two is then worked with whatever you're using as a burnishing tool (your finger can also work as a burnishing tool). The idea is that the white glue softens the paper some which allows a close joint to be made. The burnishing tool insures the joint is evenly distributed around the circumference hence "working time". Hope this helps clear up the method some.

    Gil
  7. cygielski

    cygielski Member

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    Hi Gil,
    What I was actually intrigued by was your mention of using a cork board for burnishing joints - can you explain how you do that?
  8. Gil

    Gil Active Member

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    A cork pad has many uses in card modeling but it is nearly indispensable as a forming or backing pad. It has just the right give for many of the burnishing and forming tasks commonly encountered in this art. The overall use of pad is difficult to explain in words. I suggest that you obtain one and with several pieces of card stock "play" with it as a means of introduction and practice before attempting a model seam join. Look for a pad with a thickness of 3-4 mm. A collection of burnishing tools can be found at most well stocked art supply stores in the form of boxwood clay sculpting tools. The ones I use are available in a kit of six for around 5-6 Dollars U.S. You will find that they will become indispensable over time (I also use them to form tooling aluminum on the same cork pad but that's another story...,)...,

    Best regards, Gil
  9. cygielski

    cygielski Member

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    Ok, gotcha. Have you tried the back of a mousepad? Or does it have to be cork?
  10. Gil

    Gil Active Member

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    I've used mousepads but they have too much give allowing the paper to form "forming folds" if too much force is used. The word "burnish" implies a certain amount of force and mouse pads are just too soft. Swinger's discovery (or his posting of it here) of use of a vinyl eraser for the forming of small parts was of great use to me. Backing pads become somewhat of an obcession in advanced card modeling..., you'll find that a phone book can come in handy as a backing pad with just the right "give" for certain forming tasks. I prefer using rubber diaphram cloth as it can be cleaned easily when using forming aids such as white glue...,

    So a direct answer is it has to be cork but use your own judgement as regards the task at hand.

    Gil
  11. cygielski

    cygielski Member

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    OK, here's the prop.

    [​IMG]

    I still have to work on it a bit and retouch the edges, but the basic work's done. The wire supporting the blades shows through the paper a bit too much for my tastes, but I don't think I can do anything with it now.
    The kit has a clockwise rotating prop (looking from the pilot's position), which I don't think is correct. However, I could be wrong, as the documentation I have is not 100% clear on that.
    Well, that's about it for now.
  12. cygielski

    cygielski Member

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    I've managed to push things ahead a bit. I finished the skin of one wing, and apparently figured out how to correctly shape the air intake at its base (got the designer's OK on www.konradus.com).

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    I think the segmented construction, with designed-in spaces looks a bit sloppy, but I hope that once it's all closed up I'll manage to finish it off using Swinger's acrylic filler technique. I'm open to suggestions as to what to do with it.

    I also started on some detailing, including stabilizer fairings and the cockpit, and the pile of paper scraps is beginning to resemble an airplane.

    [​IMG]

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    This is the wing structure -- the main gear struts fall on an "empty" spot, though Marek Pacynski assured me (ah, the wonders of the internet) that in this scale no reinforcement would be necessary. I think I'm going to glue something in there just for peace of mind. Again, any advice regarding this would be highly appreciated.

    [​IMG]
  13. gera

    gera Member

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    Your work looks good......................nice plane I have always liked it and have several kits of it waiting on the side 8) 8)
  14. cygielski

    cygielski Member

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    Motivated by the lightning progress of another Yak-3 build I'm following on the Polish forums, I have decided to push things ahead today. First I finished off the tail:

    [​IMG]

    I also began work on the other wing. The air intake is probably the most complicated element on this model (bending along three planes as it does):

    [​IMG]

    I modified this part a bit, cutting off the original connecting strips and replacing them with new ones that will avoid having making a lap-joint on the leading edge of the wing.

    I also finished off the pilot's cabin. I couldn't deal with its light blue color, so I painted it a dark blue-gray:

    [​IMG]

    The color change was dictated by two things:
    • a canopy must be darker than the background (the glass always absorbs at least a little bit of light), and the original color was often lighter, which looked completely unnatural.
    • even a two-bit painter will tell you that light colors "pop out" and dark ones "recede", so a dark canopy should give the impression of depth behind its surface.
    Of course, besides all this smart-alecking, it simply looks better (at least to me :mrgreen: )
  15. cygielski

    cygielski Member

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    Here’s my solution to the landing gear problem: I added a support to the wing spar:

    [​IMG]

    Following a more advanced builder on the Polish forums, I assembled the wing skin into one piece first, then inserted the framework and closed the assembly. I also used a connecting strip for the trailing edge -- this method prevents the top and bottom halves from sticking together more than you’d like. I would heartily recommend this method to anyone who has problems with flat trailing edges like I used to. The strip is glued in just under 1mm from the edge.

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    Before assembling the wing, I retouched the extra lines on the ailerons (using a blade and pencil) -- the photo shows the less attractive side, and exaggerates the effect to boot.

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    Here’s the main landing gear. The “instructions†(see above) were completely inadequate here -- I only grasped the idea of how to assemble it after looking at photos of the real thing and really giving it some thought. As it is one part ended up in the trash, because I couldn’t figure out where it went. All in all, however, the gear design looks good and seems sturdy for such a small model. I had to shorten the gear bay covers, but I’m putting that down to my own mistakes along the way.

    [​IMG]

    [​IMG]
  16. Leif Oh

    Leif Oh Member

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    I'm intrigued by the tip of closing the wing first, then inserting it over the framework. I've pondered that as an option over the weekend, after having similar troubles. Many thanks for confirming the hunch by citing Polish experts.

    And the Yak is looking good!

    Leif
  17. cygielski

    cygielski Member

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    Maybe I should have been clearer: I glued together the two wing halves, making it one big unit, then inserted the framework and only THEN closed up the trailing edge seam. Hope that makes it more understandable.
  18. Leif Oh

    Leif Oh Member

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    Got it! (Lucky I didn't try the way I was thinking about). Thanks! - L.
  19. cygielski

    cygielski Member

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    I made new exhaust pipes from scratch, because the ones in the kit were to gosh darn tiny for my big fat fingers. Here’s a comparison of the old and the new:

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    This is what it looked like in place:

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    and in the final version:

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    the oil cooler...

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    ...a few added details on the landing gear...

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    ...and that would be it:

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    [​IMG]

    Thank you and good night.
  20. bfam4t6

    bfam4t6 Member

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    That's a great looking build Cygielski, especially for 1/50 scale. It honestly looks like it could be 1/33 with all of the details it has. Great job! :D