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TOPIC: New Models for 2020

New Models for 2020 3 months 1 week ago #1160

  • ahmetcalfe
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Most probably in theory the fully 3D model aircraft and the profile model should be treated entirely differently, but so far I have found profiles very useful predictors of the 3D model's behaviour. The side profiles of a fuselage seem to act the same or at least similarly whether 3D or 2D, the side area is the same in both cases after all, go figure.They also save a great deal of building time to prove things like CG, decalage, tail area and nose length, wing location and fin size which are vital to get nearly right with these fast moving and unforgiving little models. They are also very quick to make and modify if needed.The 1mm foam model of the Javelin shown here and a similar one for the Skyray proved everything I needed to know about the bigger profile models that followed and am hoping the one I made for the Sabre will turn out to have predicted the flyability and stability of the 3D version too that I am slowly painting at the moment, we will see.
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New Models for 2020 3 months 1 week ago #1161

  • rogersimmonds
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I think each model has to be taken on a 'case by case' basis. An initial profile model is useful for a quick look see if the planform is at all feasible - rigging angle, CG, tailplane large enough, stall/spin behaviour, but even a successful profile model is no guarantee that a built up version will be equally agreeable.

A case in point is the Draken. The profile version (a very nice Jetex.org kit, BTW) flies splendidly, and is my 'go to' model when conditions are blustery and a visitor to Old Warden wants a demo:



So I thought my 'superscale' version, same planform, same CG, etc, would be equally predictable:



But it is a tricky little beast and demands a motor of just the right power. Too much and it loops into the ground; too little, it glides into the ground. Apologetically, and at some distance away, but still into the ground. :dry:

I have yet to find the 'right motor' for it. I'm hoping I can tame this uncooperative Swedish Madam with a TSP L-2 motor that I can 'bore out' to give just the oomph - no more. no less - she thinks she needs. We shall see. :huh:
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New Models for 2020 3 months 1 day ago #1174

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I've made a little progress with the F-11 Tiger, but, what with one thing and another I forgot to take any photos. :(

I stuck together another pair of more scale-like tailplanes (the 3-view I was working from was again inaccurate here, when will I ever learn?). I glued the wings on before covering (against my usual practice) using the jig shown in the photos. I took care to get the sweepback correct. There is no dihedral.

My first idea was to cover in pre-printed tissue, but the only lightweight tissue I had didn't take the ink that well, so I decided to cover in plain white. The complex fuselage was covered with numerous strips and all the tissue shrunk with two coats of 40/60 dope/thinners. Proper dope, that is, none of your 'Eezee dope' stuff here!

The canopy was attached at this stage and the coming added in acrylic paint Tamiya 'Sky Grey', which is, as far as I can tell from the poor colour photos out there, the best (or least worst) match for the real thing. :whistle:







The fin and tailplanes have been given a thin coat of dilute paint - my wife gave me a couple of her special 'acrylic' artist's brushes and the paint went on very well. So perhaps I won't have to spray the Tiger at all - just brush on a couple of thin coats. I hate spraying, so this would be good - but does it add too much weight? Ace scale guru Ivan Taylor doesn't think so. :unsure:
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New Models for 2020 3 months 23 hours ago #1175

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I like it, very tasty indeed, coming along nicely.

Roger adds: but do you approve of my 'no spray' policy? Will it add too much weight?

Answers to: worried of Jetex Towers, Huntingdon. :lol:
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New Models for 2020 3 months 19 hours ago #1176

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Probably not if the paint it well thinned and as long as it has good coverage. But then what is too much weight of paint on a model this size? I don't think I have ever accurately recorded the difference between painted and unpainted so we are all guessing..

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New Models for 2020 2 months 3 weeks ago #1177

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In the end I decided just to paint, not spray, the Tiger with a couple of cots of Tamiya acrylic white and 'Sky Gray'. Unfortunately, I picked up the 'X-22' white and not the 'XF-22 (flat white) but it doesn't look too bad. But really!!! More sign, I'm afraid of lockdown loopiness or old age.:woohoo:

The fin decoration was also painted on and the silver is Tamiya 'Chrome Silver',which I was very pleased with. The fin and tailplanes were then glued in place (using the jig to ensure accuracy). All this, I was pleased to note, added only a little over 3 grams.





At this stage I would normally take to model down to the local field for a few hand glides, just to see if it will fly, and where the CG should be, before the final painting, adding the motor mount and applying decals. But it is quite blustery and hot. :unsure:

Instead, I've been playing around with the 'shark mouth' decoration - attaching the draft template, which is printed on tissue, to the model with temporary spray mount. If anyone has any good ideas how to transfer the template to the model (for painting in black and yellow) please tell me!:kiss:

Note added: I did manage a few test glides with the Tiger after all - see the posting on the 'Flying' thread. :)
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