Space Shuttle Launch Complex 39A with Challenger STS-6 (1:144)

Real Spacecraft
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Hello everybody,

to celebrate the day of this outstanding milestone here comes the current Hit statistics of my noble fan Hugo from our German Raumcon forum, which he immediately has posted updated, what has amazed me once again.

In this I entered the current hit numbers of the other forums in which I still otherwise are posting.

While NSF (934.186) is hot on our heels, the other forums are already a long way behind:

A definitely insightful comparison.

KitMaker (3.500) on the other hand, is still in the starting blocks and is flexing its muscles.

I’m curious to the further development of this hit statistics.

2 Likes
197

Hello friends,

in the meantime I have begun with the production of the six 18’‘/12’’ outlets.

The remaining two inner outlets differ from those six thereby that they directly rejuvenate from the 24’’ ring line to 12’’ and they have a special shape that I have to bend separately.

3D-rotatable view of this area at nasatech

Source: nasatech.net

After I have slightly shortened and equalized all the bows (3,2 mm Ø) one more time, now the outlets (Ø 2,0 mm) had to be drilled out by hand at the bottom with Ø 1,5 mm for the outlet openings.

To drill the holes halfway centered, one has to go step by step and can not immediately start with the final 1,5 mm drill. Therefore, the center initially had to be center-punched as accurately as possible, because the drill otherwise runs eccentrically at the slightest deviation.

After that followed three bores, first with Ø 0,8 mm

and 1,2 mm,

and only then with Ø 1,5 mm.

Then the openings were cut in half with a razor blade. In doing so it is advisable to leave the blade in the cut and to cut on this the half opening with a second blade to not equal to cut off the entire opening, what has happened to me at the first time.

Thereby one has to take into account the different inclined position of the outlet openings towards the SRB center, which is marked in this image for the left SRB chamber behind the LH2 TSM. Thereby the outlets 1 and 3 are identical, and outlet 2 is the outlet with the special bending which was shown at the beginning.


Source: nasatech.net

And these are the items for the outlets, left in the image the identical outlets 1 and 3 and the outlet 4 for the left chamber and right the outlets for the right chamber behind the LOX TSM.

Underneath lay the discs (Ø 2,5 mm) for the deflector plates and next to them the fenders (3 mm x 4 mm), which are to be rounded from 0,1mm Styrene, and the strip (0,25 mm x 0,5 mm) for the retaining strips.

Next will follow the installation of outlets.

3 Likes
198

Hello everybody,

and now a few pics of the assembly of these outlets.

First, I have glued the rounded little fenders with the fixing rail at the end of the outlets, and then the small baffles.

what went relatively quick.

Subsequently the bows were glued with the outlets.

For exact alignment of the arrangement my little jig was very helpful again.

Now only the tapers at the transitions have to be modeled with Apoxie Sculpt.

But this still can wait a bit, because the last two 12’’ outlets on the front insides of the ring lines are still missing and differ from the previous six outlets. They taper directly from the 24’’ ring line to 12’’ (Ø 2,0 mm) and have themselves no further taper, but a tortuous curved course, as can be seen here once again.


Source: nasatech.net

As the trained eye can recognize in this image, the upper bow however is more flattened than the two rounded outlets left besides and is also a little lower, what can be seen clearly in particular in this perspective (green arrow).


Source: nasatech.net

In contrast, the bows of the outlets on the outside of the ring line lie all at the same heights level and are clearly rounded.

And that immediately raises the question of the dimensioning of these two outlets, wherein the difference in height is more important than the shape which can be modified from the previous rounding.

For estimation of the height difference I made the following contemplation in the penultimate image, whereby I have used the diameter 4,0 mm of the ring line as reference (yellow). Based on the alignments of the ring line and the two 18’’ bows the overhang (red) is about 2,4 mm.


Source: nasatech.net

Since the overhang of the flat 12’’ bow (green) results to about 1,4 mm, the height difference should be about 1 mm, which is not much, but still present.

And because a new Balsa template was required for this transition, it went with this in a proven way back to my Balsa bending bench.

And this is the preliminary result, whereby the flattened part of the bow but still seems to be a little too wide.

That’s why I wanted to bend the left bow still somewhat narrower, however without heating, which has unfortunately led to an unexpected fraction, although I was carefully.

But every now and then I have to learn the hard way too. Apparently, the plastic loses during the hot air bending its ductility and becomes brittle, which one just only needs to know, but adversity is the school of wisdom. Nobody is perfect.

Therefore here an image of a re-glued and slightly modified bow, which still had to become slightly narrower.

And only when this bow fits, it will go on with the tortuous transition to the ring line.

2 Likes
199

In space nobody can hear (the styrene) scream. This extraordinary pipe work deserves including in the recent “Death of Scratch-building” thread, as yet more evidence the premise is bull. :+1: :+1:

200

Nothing is impossible!

BTW, my Styrene is bent quite tenderly.

1 Like
201

Immaculate pipe work again…

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Stay tuned, John, it gets even better.

1 Like
203

You are making good progress on this model. I am sure that you will finish the model successfully.
Do you use a heat gun to bend the plastic more easily?

204

Thanks my friend,

you don’t seem to have read everything, my Balsa & Bending technique doesn’t work without a hot air gun.

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Hello together,

since the prototype anyway already is under the weather and does not come into consideration for the final assembly, I have experimented with him anyway and tried the subsequent bending of the transition to the ring line, in the hope that he would survive it. The bending is therefore not easy, because it has to start behind the flat bow directly what makes the clamping somewhat difficult. But two pins have been given sufficient support.

And then I have gently fired up this bending point and slowly bent down the rod at the onset of softening what went but easier than I thought.

And since has withstood the adhesive point,

And since the adhesive point has withstood, I could also take measurements up at the ring line to remove the rest.

And here is the result.

So only was missing the test on site.

This looks already quite usable for the moment, but the vertical part does not align against the shaft wall, but protrudes a bit too far at the top. The reason is that the flattened part of the bow is still a bit too long, what I had already suspected,

which is why a little fine-tuning is necessary there.

Therefore let’s go on with the modified Balsa template whose upper flat bow is still somewhat narrower.

Important for the next 45° bending is at first the fixation of this slant and the separate extension of the abutment face, as these short pieces otherwise don’t stay straight, but would rather become rounded.

To avoid this also during the following bending, even this small flat bow must be specially fastened previously.

And after bending I have preventively heated one more time in the clamped state.

After that all sides should fit closely on the template.

After that follows the last one, but at once the most difficult bending of the transition to the ring line around a relatively tight radius, because an exact positioning of the rounding template is important, but this is more or less a matter of feeling.

And this is the result.

Now the test must show whether or how well the outlet fits. And that now looks total already better than before. The upper bow is flatter and lies slightly lower than that of the forward 18’‘/12’’ outlet,

and the support still has some space to get closer.

Meanwhile, the front outlet has been slipped down a bit, because the Pattex power subsides, be that as it may!

So much for today.

2 Likes
206

This whole build and technique is a real testament to your modelling and engineering skills. The detail and effort that goes into each segment is exceptional.

207

Thank you John for your great appreciation of my previous work, which so far only shows a small part of the overall project.

Maybe you are right and even this combination is the key to success.

1 Like
208

Hello everyone,

today for a change I have bent the missing second 24’’ ring line (Ø 4,0 mm). While the thin 12’’ outlets (Ø 2,0 mm) soften relatively quickly, this thicker rod must be reheated a little longer before one can bend it easily.

Otherwise it was the same procedure again, as you can see, whereas the roundings this time even have become better than at the first ring line, this makes the exercise.

And this is the next test, this time again with the [color=blue]Rainbirds[/color], to round out the picture,

and here without the annoying placeholders.

And so the upper deck is slowly filled by the SSWS, what looks .

And finally still a total view from the front.

That’s it for today.

2 Likes
209

Hello everyone,

today I want to come back to the 18’’ Outlets, which indeed still have no outlet openings. And also lacking even the little supports with which they are attached to the SRB Supports.

That are these small metal sheets here,


Source: nasatech.net

and then these here below the SRB supports immediately above the outlet openings.


Source: nasatech.net

And with that it gets pretty tricky.

While the supports in the first image are simple square Styrene plates (2,5 mm x 2,5 mm x 0,3 mm), the lower supports have a trapezoidal shape because they sit on the slant of the SRB supports and on the flattened outlet openings. And this results in two little problems, one being the difficulty of determining their dimensions, and closely connected their mounting on the outlet openings below the support slants.

For the dimensions this image was relatively well suited. It can be seen that the outlet opening and the trapezoidal sheet ranges up to about the middle of the SRB support.


Source: nasatech.net

Accordingly the size of the support is about 3,7/2,5 mm x 3.7 mm x 0,3 mm.

For the adaptation and assembly of these supports at the outlets, I have modified my previous mounting template for the tapered 18’‘/12’’ outlets to the following Balsa jig which has the shape of the SRB supports.

The support is made of 8 mm Balsa and thus corresponds to the thickness of the SRB support. In the base plate beneath sits the 24’’ ring line for an exact alignment of the 18’’ outlet. As spacers I have used 2,5 mm H-beams (Evergreen).

Now I have fixed the location of the outlet from both sides and from above, so that it can no longer slip.

And in the gap between the support and the outlet end can now be adapted the trapezoidal support plate and also glued later.

But previously the outlet opening must be hollowed and flattened out.

Therefore at first I have tried to pre-drill the outlet end as centrally as possible with smaller diameters (up to 2,4 mm), but this is not so simple and is slightly shifted again.

After the final drilling with Ø 2,8 mm, the wall is rather thin and unfortunately unequally thick,

which is unfavorable for the subsequent warm-flattening of the opening (on the left).

Another possibility (right) would be to use a drilled Styrene pipe (Ø 3,2 mm), of which the wall would be indeed more uniformly, but slightly thicker, which would be acceptable. The form itself certainly looks cleaner.

Of which now however still had to be cut off a short end piece and to be glued at the shortened outlet end, as well as additionally refinished, which would be an additional fiddling again.

Meanwhile, I’ve bought a drill with Ø 2,5 mm which hopefully is better suited, let’s see …

Finally, I have still marked the positions of the upper support metal sheets.

Well then until soon.

1 Like
210

Lovely work as ever … And do you own a balsa wood factory… You must go through a ton of the stuff lol

211

Thanks John for your nice words as always.

This is my small sawmill with the jig pin basis.

image
image1024×768 55.3 KB

1 Like
212

Hello everybody,

now missing only the outlet openings that I wanted to try again.

The difficulty is, as I said, the central drilling, which you cannot do it immediately with the final diameter, which is why this time I drilled a dummy (Ø 3,2 mm) in smaller gradations.

After center punching as central as possible I first started with Ø 1,3 mm, specifically about 6 mm deep, that means gradually in and out, so there is no chip congestion.

And that looks already pretty centrical.

Thereafter followed Ø 2,0 mm,

Ø 2,3 mm,

Ø 2,5 mm,

and finally still a slight countersinking with Ø 2,7 mm for reduction the visible wall thickness, just because of the optics.

And then I have briefly heated carefully and gradually slowly flattened the front end (about 3 mm) with a core (0,75 mm x 2,5 mm) down to 1,7 mm height, but not this way …

And that can be quite impressive, right?

And therefore I can probably now also venture to the final outlets, hopefully it’ll work also as well then.

I have made a final test on a real component and thereto used my first 18’’ outlet prototype, which still was lying around and anyway is good for nothing. He still had Ø 3,0 mm and was due to the bendings no longer circular at the end , but came just right as a dummy.

Its end I have drilled out to Ø 2,5 mm,

and then flattened, as usual.

As can be seen, one can scratch the outlet opening also directly at the bent outlet.

And therefore I can now also get down to business with the four final outlets (Ø 3,2 mm).

And this I have implemented now, in hopes that it will fit somehow.

First, I have drilled out the final four 18’’ outlets, as already described.

So far so good, and now came the cautious forming of the outlet openings with the help of the Proxxon Gun, for what I have inserted a core.

Nevertheless, one must be extremely careful during heating, so that the thin-walled opening is not shrinking suddenly.

And how the subsequent fitting shows, the position of the opening under the balsa support looks quite passable.

And now to the lower support plates, which can be seen in this panorama of the STS-134 on the MLP 2.


Source: nasatech.net

First, I have tested my estimated size with a paper dummy, which was still a bit too small.

With the adjusted support plate of 0,3 mm Stytene it looks much better already.

So both plates can be glued now on the outlets in place.

But fast nor a quick update, the lower support plate was once more modified slightly and now stands vertically,

and then it was glued above the outlet opening.

And then came still the upper support.

Now first take a deep breath, folks.

Thanks for watching and stay tuned. The SSWS is a true challenge, which is still not finished, therefore you must be tougher than the rest like me.

2 Likes
213

Hello everybody,

but first times still an addendum to the current state of the first two 18’’ outlets with the support plates.

And for the flattening of the outlet openings on the two other outlets I have my method still slightly modified.

The opening can in fact even be better formed when one first uses a balsa rod which is flattened out gradually during heating,

after which I’ve used one of the new opening adapted core.

And this gives a nearly perfectly shaped opening.

Because of the different running lower curvature of these two outlets I had to remodel my Balsa clamp jig laterally reversed for adapting the lower support plates.

Thanks for watching.

1 Like
214

Very clever method of achieving the proper opening and then adapting the length of balsa wood rod to improve it … Very precise work… :+1:

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Thanks John,

necessity is the mother of invention, you just have to know how to help yourself and have good ideas.

1 Like