Build thread: Sport-scale IRIS-T missile, 1:3.8-ish

Discussion in 'Scratch Built' started by neil_w, Mar 11, 2018.

  1. Jul 2, 2018 #101

    Charles_McG

    Charles_McG

    Charles_McG

    Ciderwright

    Joined:
    Sep 12, 2013
    Messages:
    1,299
    Likes Received:
    11
    Location:
    SE Wisconsin
    I had serious trouble with simple Rusto 2X matte on my Saturn V decals. But it was -really- matte. Almost gritty.
     
  2. Jul 2, 2018 #102

    neil_w

    neil_w

    neil_w

    Slipshod Perfectionist TRF Supporter

    Joined:
    Jul 14, 2015
    Messages:
    3,905
    Likes Received:
    38
    Location:
    Northern NJ
    That's what I was expecting, but instead I got this:
    ultramatte.jpg

    I'm gonna print my decals tonight, clear coat them tomorrow, and hopefully start experimenting next week.
     
  3. Jul 2, 2018 #103

    Nytrunner

    Nytrunner

    Nytrunner

    Master of Rivets

    Joined:
    Oct 15, 2016
    Messages:
    2,371
    Likes Received:
    20
    Gender:
    Male
    Location:
    Huntsville AL
    The logo looks good on it whether it's dud or live. Helps educate people.

    Speaking of nose.....
     
  4. Jul 2, 2018 #104

    neil_w

    neil_w

    neil_w

    Slipshod Perfectionist TRF Supporter

    Joined:
    Jul 14, 2015
    Messages:
    3,905
    Likes Received:
    38
    Location:
    Northern NJ
    You cruel taskmaster.

    Working on it! Have to apply the decal to the base before I can continue. Which means I have to make some decal decisions, print them and clear coat them first. Making steady progress.
     
  5. Jul 10, 2018 #105

    neil_w

    neil_w

    neil_w

    Slipshod Perfectionist TRF Supporter

    Joined:
    Jul 14, 2015
    Messages:
    3,905
    Likes Received:
    38
    Location:
    Northern NJ
    OK, I have brought the rocket in from the shed, taken a bunch of careful, scientific measurements, and can say with confidence that the new paint job is a zillion point zero zero times better than the old one. I am relieved; it was worth all the effort sanding it down.
    Newpaint-2.jpg
    Newpaint-1.jpg
    In fact, it looks pretty great. There are only a couple of small defects and they are insignificant. I am excited to move forward at last.

    Actually, I *have* been moving forward, but haven't been able to show anything new for a while. Lots of sequential drying intervals of various types. Will have something interesting to show... I dunno, maybe by the end of the week if all goes well.
     
  6. Jul 12, 2018 #106

    neil_w

    neil_w

    neil_w

    Slipshod Perfectionist TRF Supporter

    Joined:
    Jul 14, 2015
    Messages:
    3,905
    Likes Received:
    38
    Location:
    Northern NJ
    OK, let's get to the nose cone. Should be done in about 3 parts. Here's part one.

    From the beginning, my goal is to recreate this in some reasonable fashion:
    nose1-0.png

    Strategy: start with a balsa nose cone, chop off the end, and then figure out some way to do all the other stuff.

    I calculated that I want a nose cone that would be about 1" in diameter about 1.5" from the base of the cone. Erockets had a 3.1" ogive cone that seemed to fit the bill.

    First I CAed it, mainly to protect it from all the handling it was about to receive.
    Nose1-4.jpg

    Then I cut a 1" hole in a piece of cardstock and used it to mark the cut line.
    Nose1-5.jpg
    I cut it very conservatively, leaving the final exact shape to sandpaper, where I could do it very slowly and carefully.
    Nose1-6.jpg

    (cutting and sanding the CAed cone was interesting; it was like it had a crunchy candy coating)

    Next up: the clear dome. I needed clear plastic, reasonably strong (but not excessively so; this is only flying on Cs and Ds), a bit over 1" in diameter since I want slightly less than a full hemisphere to match up with the 1" end of the nose cone. As previously documented, I found the perfect item at a Dollar Store after about a hundred billion hours of searching in too many stores to count. Worth it! :rolleyes:
    Nose1-1.jpg Nose1-2.jpg

    I cut off the dome with a razor and sanded it down to size, then coated it with some Future for protection, which may or may not turn out to be a good idea. End result: one lovely oversized contact lens:
    Nose1-3.jpg

    I sanded everything to matched sizes and came up with this:
    Nose1-7.jpg

    So far so good. Next I applied thinned CWF and a coat of filler/primer, and now the cone was nice and smooth. I drilled out an oversized hole in the base for a future eyelet that will have to hold some washers for weight. For this task I put the drill bits (successively larger sizes) in a vise to the desired depth, and turned the nose cone by hand onto the bits. That worked fantastically. Will get back to the eyelet and washers later (still need to figure out the desired amount of weight).
    Nose1-8.jpg

    Finally, I applied a coat of Perfect Gray to the nose, and the first phase is complete.
    Nose1-9.jpg
     
  7. Jul 12, 2018 #107

    Bruiser

    Bruiser

    Bruiser

    Active Member

    Joined:
    Jun 7, 2018
    Messages:
    41
    Likes Received:
    1
    Looks very cool too me. So are you going to insert a short piece of dowel into the balsa for the screw eye?

    Can't wait to see this all together with the decals and all :). It'll be awesome!

    Bob
     
  8. Jul 12, 2018 #108

    neil_w

    neil_w

    neil_w

    Slipshod Perfectionist TRF Supporter

    Joined:
    Jul 14, 2015
    Messages:
    3,905
    Likes Received:
    38
    Location:
    Northern NJ
    Current plan is to fill the hole with epoxy and stick the screw-eye in. Should be very strong. We'll see how that goes later...
     
  9. Jul 12, 2018 #109

    Bruiser

    Bruiser

    Bruiser

    Active Member

    Joined:
    Jun 7, 2018
    Messages:
    41
    Likes Received:
    1
    Epoxy should work well to hold the screw eye in also. This is shaping up great!

    -Bob
     
  10. Jul 13, 2018 #110

    neil_w

    neil_w

    neil_w

    Slipshod Perfectionist TRF Supporter

    Joined:
    Jul 14, 2015
    Messages:
    3,905
    Likes Received:
    38
    Location:
    Northern NJ
    Here's part 2 of the nose cone: the camera and gimbal.

    I actually lied in the previous post where I said I had intended to reproduce that nose cone right from the beginning. In fact, I originally was targeting one of the noses on one of the non-functional display units, which look like this:
    nose2-demo.jpg

    When I started to build it, though, I was unhappy with my results, and also since I changed the paint scheme from display to fully functional, the nose cone should follow suit. I collected all the pictures I could find of the functional nose, so I could see the camera and gimbal from all angles:
    nose2-collage.jpg

    It was pretty clear the only way I was even going to come close to this was with 3D-printing. So I whipped up a model in Tinkercad that seemed to approximate it pretty well:

    nose2-model.png

    ...and then spent too much money having it printed in black resin (my first SLA print). Here's the finished part, with penny shown for scale:
    Nose2-4.jpg

    Next I gathered up three bottles of Testor's enamel, and some of those super-fine detail brushes, and went to it. The results are good, although in extreme close-ups they do not fare so well:
    Nose2-1.jpg

    That takes care of everything but what I call the "iris" of the eyeball, the greenish ring surrounding the black "pupil". A lot of the pictures show a bit of gradient between greenish and a more pinkish color; I wasn't gonna be able to do that with paint so I printed and made a little (!) transition:
    Nose2-5.jpg

    I don't know if that is "Dr Zooch" small, but for me it was by far the smallest one I've made, and it was tricky. Actually the one shown in the picture is not the one I eventually used; I made another that was a bit more bluish to match the above pictures. Getting it to fit nicely onto the resin part meant making *many* of these, tweaking sizes until it was close enough to sit well (could never get it perfect). Glued it on with some CA and voila:
    Nose2-2.jpg

    I think that is a decent approximation of the real thing. It's the sort of thing that would have been much easier to do at a larger scale. Maybe someone else will try that (ahem).

    It also would have been better if the nose cone were hollowed out, so the assembly would sit "in" the nose rather than on the surface, but that wasn't an option for me.

    That concludes this chapter. The next one will put the whole nose cone together.
     
    lakeroadster and Nytrunner like this.
  11. Jul 15, 2018 #111

    neil_w

    neil_w

    neil_w

    Slipshod Perfectionist TRF Supporter

    Joined:
    Jul 14, 2015
    Messages:
    3,905
    Likes Received:
    38
    Location:
    Northern NJ
    Let's finish off that nose cone.

    The top is painted black. I left a blank area in the middle for gluing the camera piece. Originally I tried to leave a bit of blank border for gluing the dome, but I couldn't get it precise enough and it looked bad, so I just painted out to the edge. That's flat black paint, reflecting the light. In real life it is indeed black.
    Nose3-1.jpg

    The camera/gimbal piece from the previous post was then epoxied on top. At some point the decal found its way on as well.
    Nose3-3.jpg

    Speaking of that decal, I put the black line as close to the shoulder as possible, but couldn't get it quite there. I painted the little space below the black line with some Tamiya gloss black (results visible later).
    nose3-decal.JPG

    Gluing the dome on was a pain. I went to first clean it off with some alcohol, and immediately learned that alcohol clouds Future. I was relieved when another two coats of Future cleared the clouding. Even still, the dome was showing some evidence of the handling it had received, but I was not in the mood to make a new one, so on it went. First I made myself a tape "handle":
    Nose3-4.jpg

    Then I applied a thin bead of medium CA with a Q-tip around the edge of the dome, and applied it. And then, a few minutes later, removed it, having found that it just did not stick. So out came the epoxy, which I applied *sparingly* to the edge of the dome. Didn't want any extra glopping out, because I wasn't gonna use alcohol to clean it up.

    It went on pretty well, and the epoxy seems to be holding on pretty strong. In hindsight, I could have poked a few pinholes around the perimeter of the balsa nose, to make some epoxy rivets, but it looks like it won't be necessary. We'll eventually see if it all survives landing, which is always the thing.

    After a flat clear-coat the nose is finished.
    Nose3-6.jpg Nose3-5.jpg

    In the second picture you can see that the black now goes all the way to the shoulder, so when it's inserted into the airframe only a single black line should show. Also, with the flat coat, the clear decal backing *mostly* disappears; you can still see it at some angles, but I chose not to use those here. :)

    I'd say the end results is pretty nifty. Including the search for a suitable dome, I spent more time on this nose cone than on some whole rockets.
     
    lakeroadster likes this.
  12. Jul 15, 2018 #112

    snrkl

    snrkl

    snrkl

    Forum Supporter TRF Supporter

    Joined:
    Apr 11, 2017
    Messages:
    812
    Likes Received:
    4
    Looks awesome Neil!!!
     
  13. Jul 15, 2018 #113

    neil_w

    neil_w

    neil_w

    Slipshod Perfectionist TRF Supporter

    Joined:
    Jul 14, 2015
    Messages:
    3,905
    Likes Received:
    38
    Location:
    Northern NJ
    Thanks! It looks even better on the rocket, but I'm not showing that until the full reveal at the end. Gotta save something. ;)

    Main rocket decals are in progress, coming out pretty well so far.
     
  14. Jul 15, 2018 #114

    BDB

    BDB

    BDB

    Absent Minded Professor

    Joined:
    Aug 22, 2015
    Messages:
    1,365
    Likes Received:
    4
    Gender:
    Male
    This is awesomeness!!!
     
  15. Jul 15, 2018 #115

    Nytrunner

    Nytrunner

    Nytrunner

    Master of Rivets

    Joined:
    Oct 15, 2016
    Messages:
    2,371
    Likes Received:
    20
    Gender:
    Male
    Location:
    Huntsville AL
    it's going to be difficult to put on the nose cone with "No Support or Handling" beyond that line
     
    neil_w likes this.
  16. Jul 15, 2018 #116

    neil_w

    neil_w

    neil_w

    Slipshod Perfectionist TRF Supporter

    Joined:
    Jul 14, 2015
    Messages:
    3,905
    Likes Received:
    38
    Location:
    Northern NJ
    You know, you had about a HUNDRED opportunities to warn me about that before now.

    I am now well and truly screwed. Build is over folks, I'm taking my ball and going home. :mad:
     
  17. Jul 15, 2018 #117

    Nytrunner

    Nytrunner

    Nytrunner

    Master of Rivets

    Joined:
    Oct 15, 2016
    Messages:
    2,371
    Likes Received:
    20
    Gender:
    Male
    Location:
    Huntsville AL
    Trying to decipher and investigate those markings was kind of fun
     
  18. Jul 15, 2018 #118

    sooner.boomer

    sooner.boomer

    sooner.boomer

    Well-Known Member

    Joined:
    Mar 21, 2011
    Messages:
    2,129
    Likes Received:
    3
    Looks pretty sweet. Working with details at that small of a scale can be challanging!
     
  19. Jul 15, 2018 #119

    neil_w

    neil_w

    neil_w

    Slipshod Perfectionist TRF Supporter

    Joined:
    Jul 14, 2015
    Messages:
    3,905
    Likes Received:
    38
    Location:
    Northern NJ
    Indeed. This would have been a much different project if this missile were fully documented somewhere.

    Although I’m perpetually self-doubting about whether I’ve made the right choices regarding the decal scheme, I think anyone would look at the end result (once I get there) and say the whole thing is a pretty solid sport-scale representation.

    2/3 of the way through the decals it is looking really good. Bolt heads come next, some tricky bits await.
     
  20. Jul 15, 2018 #120

    KevinM

    KevinM

    KevinM

    Well-Known Member

    Joined:
    Sep 4, 2009
    Messages:
    97
    Likes Received:
    0
    I'll echo what was said a long way back - what a great build, I can't believe it took me so long to find this!

    Although it can make for a bunch of extra steps, if you do any more builds with decals like this you may find that the clear parts disappear better (and will certainly adhere better) when put down on a gloss surface instead of a flat one. You're going to over-coat it with flat anyways, right? The tricky part with this is finding military colours in a gloss finish, otherwise you need to paint, gloss-coat, decal, then dull-coat.

    Another thought on the finish for the dome - you may come to appreciate the way a gloss finish on the dome compared with a dull finish on the rest of the model helps to draw attention to all the wonderful work you put there.

    Thanks as well for posting the source on those clear domes. I'm going to have to take a look around and see if I can find something similar for the "XBT cover" on my 1/2 scale TOW.
     

Share This Page