F-117A • Nighthawk

[Uilleann]

One trick I use in my optician day job that might help to deepen the "dark" effect of the acrylic, is to paint the edges black as well, before gluing in place.  I don't suggest scuffing them first as it will possibly give the paint more surface to "bite" into, it also gives the edges a frosted look that may be visible when they're in place.  I do understand that painting the edges makes gluing them in place much trickier.  But if you can pull off a nice black edge coat, I think it may help to deepen the effect even more.

 

This is assuming you haven't already glued the acrylic in place of course!

 

Cheers

 

*Edited to add: it looks like perhaps you have already done the above, in your previous post, and I'm just slow to realize it!  Also, the interior of F-117A intakes was a sort of dirty off white on the actual jets.  Not that it matters terribly of course.  I know these screens gave me no end of headaches myself - even after I figured out more about the actual mechanics and shapes of the vanes.  I still hope to one day get them 3D reprinted, or perhaps done with stereo lithography to recreate them in better fidelity at scale...

 

 

Brian~

Edited March 28, 2020 by Uilleann

[F`s are my favs]

Btw I used black oil paint for the acrylic parts so I think they are as dark as they could be. 

Thx Brian for the tip on the intake colors as well. While for your design of the intake screens - yep, I'm very well aware of it, I keep checking your F-117 topics from time to time indeed, for inspiration. Initially I thought about contacting you to ask whether you make them. I think it is a very nice approach but I'm doubtful about how rigid/solid those screens could be. The tiny little vanes or cones would be so small that ... I don't know, I can't even imagine. Because it's very important to be safe for handling and to "stay in shape" when touched ever so slightly. 

Edited March 28, 2020 by F`s are my favs

[Uilleann]

3 hours ago, F`s are my favs said:

Btw I used black oil paint for the acrylic parts so I think they are as dark as they could be. 

Thx Brian for the tip on the intake colors as well. While for your design of the intake screens - yep, I'm very well aware of it, I keep checking your F-117 topics from time to time indeed, for inspiration. Initially I thought about contacting you to ask whether you make them. I think it is a very nice approach but I'm doubtful about how rigid/solid those screens could be. The tiny little vanes or cones would be so small that ... I don't know, I can't even imagine. Because it's very important to be safe for handling and to "stay in shape" when touched ever so slightly. 

 

My biggest issues to date have just been life, and time, followed by CAD modeling skills (or the utter lack thereof).  And of course, finding a printer capable of the resolution and fidelity needed to pull off the parts.  Due to their depth, I actually think the printed parts would be plenty sturdy enough for our purposes...I just need to sort out the final design, and fine someone insane enough to make them for me. 

 

Long story short, I just haven't had a chance to really sit down and focus on that here since the latest move.  Been busy dealing with work, the Covid, earthquakes, and any other number of life's little surprises.  Love following along here as you go though!  Keeps that flame of motivation burning in my mind...even if faintly for a while yet. 

 

B~

[Crew Dog]

Awesome work on her! This was one of the jets that made me enlist in the USAF (they sadly "retired" her the year I joined.) I built Testors offering years back.

[F`s are my favs]

Thx a lot!

Now, on to the exhaust... It would take a lot of time for the black oil paint on the intakes to dry so now a little bit of modifications on the rear part of the plane. After a thorough examination... the first pic is the real plane, b&w, while on the second pic I tried to capture the same angle:

 

 

 

and the opposite side:

 

 

So, there will be quite a lot of editing here. At first glance:

 

- the entire width of the exhaust is a little bit too too much. The upper lip is way thicker, it needs a lot of thinning but from the inner side, so the thickness of the exhausts will become even more; so I'll have to reduce it by cutting/displacing the lower platforms (a couple of mm, just a bit, but I have to).

- the tiny guide vanes are not exactly tiny. They need a lot of thinning, they should be about about twice shorter, they are perfectly straight but need to be a little bit canted inwards, and they need an airfoil profile. Here is a closeup of the real deal, b&w again:

 

 

And the original guide vanes. I think I could use them and reshape them instead of entirely replacing them with PE parts. 

 

 

 

 

[Shawn M]

wow, it appears every vane is different in size, and cross section from that pic, some even show "bulges" while the others are longer sickle shapes

[F`s are my favs]

Half way in the making: this is the overall decrease of the width of the exhausts - done on the portside, still the original on the starboard side. It is a small change but a big difference, it's way better now.

 

 

Then I prepped the part with the vanes. I cut off the original ones and "redistributed" new slots according to the pattern of the real plane. This is... I took a pic with the plastic part just put over the screen of my laptop then by syncing the image below by taking the lower lip of the exhaust as a reference. I also shortened the slots for the vanes - the original ones took the entire width of the plastic part.

 

 

This is, still not done, but just a test fit with some plastic pieces that I'll later use as vanes. Here is the difference between the arrangement of the vanes on the original kit part still not edited, and the new one.

 

 

 

It's something like 2-3 out of 11 vanes to stay on their initial places where they were... all others needed a "relocation".  Happy to do it justice. Of course this is just a bare test fit. I'll try to thin down the trailing edges, equalize the lengths, cant them slightly towards the centerline. And hopefully some airfoil profile... but I'm not quite optimistic on that.

 

[Eagle Driver]

[F`s are my favs]

The vanes for the starboard side are done... this is all a test fit only.

 

 

However... although I reduced the overall thickness of both exhausts quite significanlty, it's still not enough :| Here is the original plane again:

 

 

and here I did some trials with 1 piece of plastic sheet just put over the current plates... you can see it on the right-hand side of the exhaust:

 

 

and with two pieces stacked:

 

 

Very difficult to find out the truth... should I add one more piece or two?! I think one is not enough, while two pieces are a little bit too much. I gotta think how to do it with one and a half indeed... I think this is the right thickness to add. Alright, the same journey again . . .

 

Btw here are the vanes only:

 

 

[Uilleann]

Can you do the two pieces, thin each by about 25%, and use one on top, and one on bottom, so as not to thicken the bottom plate and lip too much?

[F`s are my favs]

10x for the tip Brian! I just did it yesterday by using a wire which is just about thinner than the plastic sheets. Here is how itthey looks now. I'll wait them to dry completely and then I'll have to smoothen/blend the trailing edges of the sheets:

 

 

And here is a view from the inner side. The fuselage is flipped. With the red is the firstly added "thickness" while the white is the newly added space. And you can see the wire rods shining inbetween. Whilst for the initial thickening I used just two thin stripes from/with the width of the plastic sheets. Quite a sandwitch indeed. 

 

 

Edited April 13, 2020 by F`s are my favs

[F`s are my favs]

Alrighty : ) The baffled outlets are done, thinned, painted, just about ready for gluing, but after a thorough thinking - it turned out that the reat area of the upper fuselage will become very fragile/delicate to touch if I add the vanes. The next pix are quite of a micro - the thickness of the vane is half a milimiter. And because I want to make the ruddervators moveable, I'd rather make them now when the rear part of the fuselage is still not so risky for action.

 

 

 

 

And just a couple pics with the slotted areas over an artificial light... quite nice! But... ruddervators first  

 

 

 

[Troy Molitor]

Fantastic efforts going on here.   Love all the updates.   

[F`s are my favs]

The ruddervaters are partially done. For the hinge I used a shorter rod but a stainless steel one

 

 

 

 

 

They are glued now and just barely sanded along the glue lines. But here is the issue - while I was watching those ruddervaters, they seemed to me way too thick. The F-15 rudders are 1/3rd thick in comparison. So, was it normal because the F-117 is not a supersonic jet or what!? I watched so many pics before and never payed too much attention to the ruddervaters for one reason or another. Then after studying the pics of the jet again and again, I think I figured it out. There is are facets with a promiment edge that runs along the entire ruddervator on both sides - okey - but this facet makes a smooth transition between the central edge and the facets of the leading/trailing edges on both sides. I don't know how to explain it but the kit parts are slightly wrong and because the angle of the facets is so shallow it is very niticeable at the top edges of the ruddervators. Here in red is the thing that should not be like that:

 

 

 

Check out the real thing:

 

 

 

The central edge is there - ok; the trailing/leading edge facets near the base of the ruddervaters are there - ok; but the end sides finish in a romboid shape.

 

 

 

This will be quite an adventure to edit it but I think I know how to do it justice.  And hopefully this will reduce the overall thickness of the ruddervators in their top areas too. 

Edited May 7, 2020 by F`s are my favs

[Dutch Man]

Superbe! Or even better!!! 

Like the Germans used to, I call this outrageous kind of performance:. "Super Affen Titten Geil!"

 

Robert Jan