HK B-17...C 5/4 sweating the metal

[brahman104]

Thanks Matt!

 

Did a bit more this arvo, including adding the windows. I did these straight off the side view just to see how they'd look, which isn't too bad I might say

 

I'll probably go back at some point and draw them according to the boeing dimensioned drawings that Terry sent me ages ago. I wasn't going to worry about them till later when I made correct brass inserts, but then I had a change of heart and thought, why not see how close I can get it now?

 

She's starting to come to life..... think I got the windscreen "look" finally!

 

 

 

 

 

 

 

As always guys, feel free to suggest any changes. They're much easier to do now than later. I'm hoping to have this ready to print tomorrow. Fingers crossed!

 

Craig

[TKB]

Craig,

 

That's some pretty amazing electronic modeling you're doing there!

 

Before you do another 3D shot, two things.

 

We all keep referring to the "flat spot" and "flattened nose area". I don't think we are talking about a true flat as much as a circular Bulkhead #3 with a "squashed" top. A true flat area may throw things off again.

 

Back in the 1960s, I had some modeling plans from Boeing that were pretty good.

They did show Bulkhead #3 as being "not a perfect circle". In the process of re-scaling the plans, I was able to reproduce Bulkhead #3 just using a compass and adjusting the centerpoint. While there was no actual flat spot, the top did look to be flattened out.

 

It may just be the photos, but maybe revisit the 5 an 7 o'clock positions Bulkhead #1 and compare to reference photos.

In the Rhino photos it looks like one continuous soft curve inwards until it meets the bottom, whereas it should bulge a bit at 5 and 7.

One main bulkhead circle and two small circles at 5 and 7 that intersect with the main one and a straight line connecting the bottom edges of the two small circles. This all sounds familar; I think I already brought this up, didn't I?

 

Anyway, some fine work and I hope it translates into 3D as well.

 

Terry

[brahman104]

Thanks for the feedback Terry!

 

I spent so much time fiddling around with the cockpit windscreen area I completely forgot about the shape where the nose transparency sits. I'm pretty sure I made the same mistake with my first effort too, so I'm glad someone's on the ball!

 

Anyway, with the above corrections incorporated, here's how it stands as I go to print....

 

 

 

The perspective view on the screen does distort the shape a little, but once again I feel I'm close.

 

Anyway, I decided to have a go at printing it and see what happens. Each side will end up being in three pieces. This is partly due to the "print volume" of my machine (about 120mm in height) and partly so I can leave the lower nose separate to detail the interior and do the soundproofing. As I said earlier, this will be a line that parallels the floor, so it should be effectively invisible once joined... there's the theory anyway!

 

The first piece is printing now, so wish me luck!

 

Craig

[Juggernut]

 

I'm still playing around with the top shape of the sta #3 bulkhead, as I believe this is the linchpin to the whole show. 

 

 

Amen!  FINALLY....  Someone else who can actually see the shape of fuselage frame 3 is off and therefor throws off the rest of the upper deck.  Sorry, didn't mean to hijack the thread.  Just overjoyed that someone other than a very few of us actually sees the misshapen nose and how it affects the rest of the upper deck of the fuselage.  I do love this thread though.  You've got way more gumption (and skill) than I have to  tackle such a daunting project as this but I'm looking at it with great admiration and a good healthy dose of

Edited February 7, 2016 by Juggernut

[brahman104]

Thanks Jug!

 

It's been a lot of playing around and more than a little help from TKB and others, but you are right, the shape of this part does seem to be critical. I'm looking forward to seeing how the print comes out. 

 

The B-17 is too beautiful a plane not to do this area justice; even if it adds another year to the build then so be it! The rhino/3D printing learning curve has been steep, and I'm far from an expert in the field, but I guess the beauty of it is I can keep going back and tinkering if something still looks off and I can just keep on reprinting till I get it right.

 

Of course at the end of the day it will still not be perfect, I'm only aiming for the best possible blend of the HK effort and my own work, but as long as I'm content that I've given it the best go I could, then I'll be happy with that.

 

Thanks again for joining me on the journey, no idea where it's going but it's a whole bunch of fun! 

 

Craig

[Hubert Boillot]

Looking good Craig. The upper half of bulkhead #3 is not flat, but rather the whole shape is elliptical. You sem to have captured the look of it. I don't want to pollute your thread with yet anothre debate, but this is a very noticeable feature of the originla aircraft, and key to avoid the look of "a box posed on a tube" of the cokpit fairing vs fuselage of the kit.

 

Great job Craig. Your thread certainly shows the possibilities of this technology for our "little planes".

 

(I have now started to master Solidwoarks, but I need to have a good look at Rhino now that the Mac verson is finally available. I run Solidworks on Parallels on my Mac, but even though it is a powerful machine, it sometimes slows down too;much when running Solidworks in this configuration. )

 

Hubert

[TKB]

Craig,

 

You original work on the nose/cabin was pretty impressive, but each tweak of your design has brought the "look" ever closer to the real thing. To your credit, you haven't taken the "I did it once, I ain't doing it over again"  attitude. Getting kit parts and scratch built parts aren't always the easiest to meld together. When you're satisfied with your work, it may not be 100% perfect, but it's obviously going to be as close as it's going to get ---- and one of a kind.

 

You mentioned "might add another year to the build." I'm fairly confident once the nose/cabin issue are put to rest, you'll progress along quickly. For you to measure this build not in weeks, but months or possibly more, just shows the dedication and patience you're putting in to this project. Glad you're still "enjoying the ride" as you progress forward.

 

I assume you're going to "lop off" the original forward fuselage at #4 Bulkhead. Are you going to be able to salvage your cockpit interior assembly fairly intact?

 

Terry

[brahman104]

Okay folks, here we are (drum roll.......)

 

 

Looks like it pretty much came out okay!

 

I know these look pretty rough, but bear in mind all I have done is separate the pieces from the raft. No clean up, no finishing yet..... but at least you can now see the part in the flesh, so to speak.

 

 

 

AS you can see, probably the worst rendered part is the windscreen and frames, but that's okay, as I was going to do these again in brass for extra "sharpness." Same goes for the little windows in the nose. You can also see that I have left the taper "transition" section in under the cockpit roof; that will be removed next. Leaving this piece in meant there was a bigger "footprint" on the print bed, which allowed the part to grip the surface better. A few times now I have tried to print parts without this, and sometimes the action of the print head moving across the top is enough to dislodge the part. If that happens, the print is ruined and it's start over........It is also still there due to the fact that I am not clever enough to remove it in Rhino with the intersections of the pieces, so I figured I just remove it once everything had finished

 

 

 

I assume you're going to "lop off" the original forward fuselage at #4 Bulkhead. Are you going to be able to salvage your cockpit interior assembly fairly intact?

 

Terry

 

Absolutely mate. It will be more of a "step" in section. This is because I want to preserve the shape of the fuselage to wing join at the leading edge, so I don't run into any nastiness later, and it will theoretically give me more surface area for the join, therefore more strength. The next part about the salvage of the cockpit? Well I sure hope so..... THAT I can live without doing again!!!!!

 

 

You can see on the above photo that there's been a slight mischief in the print along the bottom of the cockpit side windows... the "faired" area is not there..... No idea why, sometimes the prints just do their own thing. There's no difference in the drawings between the left and right sides, in fact I copied the left side for the right as you may recall. 

 

This is a lesson I have learned in the world of 3D printing.... no matter how good or amazing your original drawing is* in Rhino, there's no guarantee that it will lead to success on the print bed. Who knows? I could try a reprint and it might come out better.... but it could also come out worse. I n any case, I can live with that, as I feel pretty happy I've address the two points I wanted to with this redesign anyway

 

Next up, you'll see a flawlessly shaped 3D forward fuselage grafted effortlessly onto the ever shrinking original kit part.

 

Yeah right...........

 

Craig

 

*None of the drawings featured here are good or amazing in case you were wondering

Edited February 9, 2016 by brahman104

[ClumsyDude]

Craig, you are a modelling rock star. Some of the most impressive determination - and purest scale awesomeness - I've seen anywhere. Love it.

 

Jim

[LSP_Kevin]

Oh man, are you serious? Rock star is right!

 

Kev

[brahman104]

Jim, Kev, thank you!

 

As long as it looks a little more like a B-17 than the original, I'm happy!

 

[misha71]

Good luck my friend in this magnificent progect

Wark you are doing is reason i like in this hobby

[Hubert Boillot]

Great work Craig ! And impressive result !

 

Hubert.

[Shawn M]

wow now thats cool

[brahman104]

So you know that graceful match I promised you? 

 

It actually turned out pretty darn good! 

 

First of all, some more of the kit had to go....

 

 

Then this happened...

 

 

And now we have this....

 

 

Okay, so the swap wasn't entirely seamless as promised... Somewhere along the way I must've stuffed up the roof width.... no big deal, I'll address that later when I do the windows in brass....

 

 

So was it worth the effort?

 

Here's some comparison pics between old and new.

 

 

 

 

 

Height of the windows....... Was I on the crack? That was NEVER going to work!!!!

 

 

Happy with that!

 

One other little thing I noticed....

 

 

The bottom of #3 bulkhead encroaches into the opening of the forward door a little now..... 

 

The way I see it there are three options:

 

Option A: remove the lower half of bulkhead #3 and place it 2mm further forward, at the same time address the offset nose entry door. No one will notice the difference between the top and bottom when all buttoned up.

 

Option B: remove a further 2mm off the "splice" cut I just made, the overall length being 2mm shorter, but no one will probably notice once it's all together anyway.

 

Option C: cry.

 

Option B is the easiest to do, however it may come as a surprise to learn that I don't normally take the easiest way out Option C is probably not going to be overly useful in the long run. Option A would allow me to sleep better at night, but I could run into problems with the underfloor details.......

 

I shall examine the problem further, but overall I am thrilled with the way that came out and amusingly, how close I was in a few areas considering I was initially using some highly questionable reference material!

 

Thoughts or comments are always appreciated.... thanks for looking

 

Craig

Edited February 10, 2016 by brahman104