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Space Shuttle Launch Pad 39A with Challenger STS-6


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It sort of looks like Shapeways  missed the fourth version, "WTF".  You'll get thing straightened out tho, and it will all look great.

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Hello everybody,

 

in connection with the planned Flour-Technique for the production of the ET's Instafoam insulation I receiced a hint by David Hanners (papermodelers.com/forum), that this structure alone  would not be sufficient, in order to faithfully reproduce the ET. nono.gif  He meant that I would necessarily have to consider the typical annular bands in the insulation too, wherewith he probably wanted to challenge me. top.gif

 

Maybe some of you know David Hanner's contribution "Detailing the Space Shuttle" in Michael Mackowski's "Space in Miniature #3" book

 

When he built a Shuttle Stack (1/144) ages ago for this contribution, he coated bands of the ET with liquid cement to soften the plastic, then scuffed the surface with heavy-grit sandpaper, turning the ET during he sanded. He worked in sections, and finally he softened it up with medium sandpaper. up045518.gif

 

Unfortunately I have only a black&white copy, on whose figures one cannot see the details of his stack clearly enough. rolleyes.gif 

 

Although I had an idea what he meant with the annular bands, I was not sure.

 

But Michael Mackowski was so nice and had thankfully sent me some scans of David's original photos like these here. speak_cool.gif

 

yz0fUF.jpg

 

SCyuxj.jpg

 

p3Ic98.jpg

 

As one can see in the photos, he had roughened the ET in circumferential direction with sandpaper, which was a promising approach, but that's not the typical Instafoam structurei5684_no2.gif

 

Independently, the crucial question for me is always how certain details looked at the STS-6top.gif

 

Xratqe.jpg
Source: retrospaceimages.com (STS-6)

 

08pd2368.jpg
Source: NASA (STS-126)

 

BTW, in my view, not this structure but the Intertank is the dominant structural feature of any External Tank, especially since this band/ring structure is not always very distinct. up045518.gif

 

But at least he made me think, though it could surely become difficult to create such a regular as well as delicate structure. hmmm.gif

 

My idea for the ET front end is relatively simple and came up when I looked at my WSF-IT, especially at the sight of the fine ribs in the Thrust panel.

 

2rdfBn.jpg

 

There are 26 ribs in this panel, which is approx. 24 mm wide, corresponding to approx. 0,9 mm for one rib. 

 

Therefore, I imagine this ET front part as WSF 3D print with adjacent annular bands at a distance of about 0,9 mm. 

 

U7Xhv3.jpg

 

It would be ideal if these bands would become flatter towards the nose. Or one could choose a uniform height and sand off these bands softly to the nose. 

 

But I think that a good 3D designer can easily model such a front piece, which is why I have already asked Michael Key, if he could do this job. top.gif

 

In this image I tried to count the bands from bottom to top, which is not that easy, and came to about 55cant-believe-my-eyes-smiley-emoticon.gif

 

H5aeGx.jpg
Source: retrospaceimages.com (STS-6)

 

Depending on what this structure of the 3D front part looks like, one could also use the Flour-Technique to level out the gaps if necessary. 

 

For the ET rear part (185 mm), this approach would also be possible in principle, although I do not know what height Shapeways can print. But even a division into three parts would be conceivable without thinking about the costs. eek.gif

But I could also imagine a different solution without 3D printing, with a lot of small Evergreen strips plus Flour-Technique, or better not?  idea1_2.gif

This is really a tricky matter ... up040577.gif

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Another challenge for your Challenger. This looks like a very time-consuming task with Evergreen strips. It seems to me the depth of the undulation is very small. Could you put on one layer of flour-paint, remove narrow rings of the paint from the ‘valleys’ and then give another flour coating?

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If it were me, I'd be tempted to simulate those bands with various tints of paint, sprayed on "dry" (i.e., from a greater distance than normal so that the paint partially dries before reaching the surface of the model). This would yield a rougher-than-normal surface, which would simulate the texture of the sprayed-on insulation.

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Consider the cost of the 3D printing.  I like the texture of WSF, and craftsmanship, but the cost of these parts are very expensive.  Remember that a good Scratcher could always find an alternate solution and material.

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Thanks Mark and Michael for your well-meant comments, :worthy:

 

but the overall "pebbled" or rough surface of the Istafoam structure I can create by using the Flour technique that my Raumcon friend (inselaner) invented, no problem. top.gif&key=e896a02d20fce3e69aff6c90ad2a

 

up027618.jpg

 

up027646.jpg

 

up027748.jpg

 

The tricky problem is the fine band or ring structure on the surface, which could be simulated possibly by WSF 3D printing, if one were to model a narrow and very flat  wave-like ring structure by creating fine grooves (approx. 0,3 mm) in about 1 mm intervals, much like between the fine ribs in the Thrust Panelsup045518.gif

 

Because of these minimal distances, a removal of narrow rings out of a first flour coating is impossible, i5684_no2.gif especially since this layer is only wafer-thin, sorry Mark. rolleyes.gif&key=49124488e0487edf07b3db6

 

I hope that the matter has become a bit clearer now. up040577.gif&key=327a20a361d18ad6d35cabf

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6 hours ago, RichO said:

Consider the cost of the 3D printing.  I like the texture of WSF, and craftsmanship, but the cost of these parts are very expensive.  Remember that a good Scratcher could always find an alternate solution and material.

I fully agree with you, Rich, that's all right. top.gif&key=e896a02d20fce3e69aff6c90ad2a

 

As I said, I could also imagine a Scratch solution. For this one would have to glue "only" about 170 flat Evergreen strips, maybe 0,25 mm x 0,5 mm or 0,25 mm x 0,75 mm, each at a distance of about 0,5 mm around the ET, followed by a Flour technique coating, whereby this wave-shaped ring structure could arise. hmmm.gif

 

 This one could check out in a test with a little less strips. up040577.gif

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I have never seen this "flour technique" before.  What a gorgeous finish and texture!  Certainly something to consider.

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Could a steel comb  used in some manner not produce parallel lines? Maybe direct onto whatever surface texture you end up using or painting it with an ever so slightly lighter undercoat and then using the comb to remove lines of the top coat. At this scale that might be all you would need.

 

Or another option - to wind thick thread around it before the flour? Don't know how good or easy either idea would be in practice or to achieve.

 

Keith

Edited by saturnapollo
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On 5/29/2018 at 2:26 AM, RichO said:

I have never seen this "flour technique" before.  What a gorgeous finish and texture!  Certainly something to consider.

 

I fully agree with you, Rich. top.gif&key=e896a02d20fce3e69aff6c90ad2a

 

That was an ingenious idea of my friend, which immediately convinced and absolutely thrilled me, yahoo.gif  even though the typical Instafoam ring structure is missing ... hmmm.gif

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On 5/29/2018 at 5:26 AM, saturnapollo said:

Could a steel comb  used in some manner not produce parallel lines? Maybe direct onto whatever surface texture you end up using or painting it with an ever so slightly lighter undercoat and then using the comb to remove lines of the top coat. At this scale that might be all you would need.

 

Or another option - to wind thick thread around it before the flour? Don't know how good or easy either idea would be in practice or to achieve.

 

Keith

 

Thanks for your nice tips, :worthy:

 

regarding the steel comb, this is almost impossible to realize because the distances of the grooves of only approx. 1 mm are much too small. eek.gif

 

The same would apply to the thread, which would also only create a spiral. up040577.gif&key=327a20a361d18ad6d35cabf

 

This is really a tricky matter ... smiley215.gif

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Hi everybody,

 

in the ARC Forum I got an interesting hint to Simon Atkinson, who used a lathe for simulating the grooves in his External tank. He is a professional modeler and illustrator since more than 40 years and here is his awesome Shuttle stack (1/72), which is currently (2016) in store at The London Science Museumtop2.gif

 

SA%2000104editsml.jpg

Source: satkinsoncreativearts.com

 

A similar technique, e.g. by engraving the grooves, I have already imagined, but unfortunately I have no lathe, which would probably need a CNC control to get even intervals. hmmm.gif

 

But for that, 1/72 is of course much more workable, especially since the grooves should be at least 2 mm apart. rolleyes.gif

 

This approach is marvelous, but if you take a closer look at its texture, the grooves for my taste are a bit too pronounced and smooth, because only perfect even grooves are created with the lathe, and thus seem almost a bit artificial. smiley215.gif

 

3hqkC0.jpg

 

Nevertheless, I think that this structure could also be simulated for a 1/144 ET, if one can realize the corresponding spacings of approx. 1 mm by a clever 3D modeling of a narrow and very flat wave-like ring structure by creating fine grooves (approx. 0,3 mm) in about 1 mm intervals, much like between the fine ribs in the Thrust Panelstop.gif

 

Regarding the Spray On Foam Insulation (SOFI) of the ETs one has to distinguish early and later missions, as for the Orbiter's TPS Tiles and Blankets.

 

In the earlier missions like STS-6, this wave-like ring structure was more pronounced, while it is less or barely visible in later missions. Later at the SLWTs, the SOFI was also much more evenly applied and reworked. up040577.gif

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Not sure you would actually notice the spiral effect with the thread.

 

Re the steel comb idea, how about this;

 

https://www.ebay.co.uk/i/132521713963?chn=ps&adgroupid=43920634520&rlsatarget=pla-359427365517&abcId=1063846&adtype=pla&merchantid=113746022&poi=&googleloc=1007326&device=c&campaignid=797602469&crdt=0

 

Still not sure how practical it would be though. Just an idea.

 

I agree that, nice though the above model is,  the grooves are too pronounced.

 

Keith

Edited by saturnapollo
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Thanks Keith, :worthy:

 

I know such Profile Gauges, but I can hardly imagine creating this groove structure therewith evenly across the entire circumference and over the entire length of the ET. hmmm.gif

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Hi everybody,

 

last but not least, in the NSF forum I have still found now a Hi-Res. photo of the during STS-6 used ET-108 on which one can recognize this structure very well on the long LH2 Tank, which confirms my previous imagination. top.gif

 

uctRpZ.jpg

Source: nasaspaceflight.com (woods170)

 

As one can see on this, in the SOFI insulation foam there is in fact a uniformly rounded wave structure, which possibly was to be realized either as 3D print (WSF) or by means of my envisaged variant of Evergreen strip-rings + Flour technique

 

And that also explains now the alternating light-dark effect of the bands, which is not a color effect, but only created by the shadows of the "hills" in the "valleys". up040577.gif

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Dear friends,

 

sadly we must take note that Donald H. Peterson, one of the crew members of STS-6, passed away a few days ago. 

 

750px-Sts-6-crew.jpg
Source: commons.wikimedia.org

Seated are Paul J. Weitz (left), crew commander, and Karol J. Bobko, pilot. Standing are Donald H. Peterson (left) and Story Musgrave, both mission specalists.

 

41756716084_523b3bbd3e_b.jpg

 Source: flickr.com (NASA Kennedy)

 

This sad news consternates me deeply, especially since Paul J. Weitz left recently too.

 

Forever remembered, may they all rest in peace ...  pray.gif

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On 5/31/2018 at 5:00 PM, roma847 said:

 

Thanks for your nice tips, :worthy:

 

regarding the steel comb, this is almost impossible to realize because the distances of the grooves of only approx. 1 mm are much too small. eek.gif

 

The same would apply to the thread, which would also only create a spiral. up040577.gif&key=327a20a361d18ad6d35cabf

 

This is really a tricky matter ... smiley215.gif

I was going to say "You cold try a profile gauge. The teeth are very close and not too sharp, and you can (as it says) set the profile to fit the tank and that will avoid the spiral" but see that its been raised. Still, if you fond a long on e(and there are ones out there) .....

Edited by Mass
My stupidity and rushing :(
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Thanks Mass, :worthy:

 

as  said, I know such Profile Gauges, but I can hardly imagine creating this groove structure therewith evenly across the entire circumference and over the entire length of the ET. hmmm.gif

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Hello everybody,

 

after the tough struggle for the rings of the ET smiley_worship.gif now back to the grooves of the last FUD-IT, whose ultrasonic cleaning in the Dental lab was still on the agenda. cool.gif

 

For that I had procured the recommended intensive cleaner TICKOPUR R 60

 

up063248.jpg

 

which we wanted to use based on the conditions recommended by BANDELIN

 

up063249.jpg
Soure: bandelin.com

 

Since this cleaner i.a. Sodium hydroxide (5-15%), also called caustic soda, caution was bidden, which is why protective gloves were required.  schlaumeier.gif

 

After the nice colleagues of the ChiliDent Lab were back on board after their short break, it was finally time and the Final Countdown was imminent. top.gif

 

In the beginning of May in my #1457 I had presented the critical areas with the strongest wax nests and captured in pictures.

 

In order to shorten the cleaning time, we have increased the concentration of the TICKOPUR to approx. 20 %. Through the rubber ring, the height of the glass insert in the ultrasonic bath could be adjusted so that it hung about 3 cm above the bottom of the tub, which is as important for optimal cleaning as filling the tub with the same solution, 

 

wm2Unn.jpg

 

that the boss has personally mixed.  up045518.gif

 

XaW0Zt.jpg

 

Due to the size of the glass insert, the Intertank could be inserted lengthwise, which is also advantageous for the cleaning effect. 

 

After setting the thermostat to 70 °C, the appliance was switched on by the assistant, cool.gif

 

8h3NL1.jpg

 

40ynJ3.jpg

 

and the bath began to bubble. speak_cool.gif

 

wSYaxk.jpg

 

After every 30 minutes, the IT was turned a quarter turn further. Overall, the cleaning time was about three hours.

 

After that, the tank looked white and completely clean, which one could already see at first glance. top2.gif

 

meguag.jpg

 

tPnShb.jpg

 

So finally the work was done, and with a tip into the kitty I thanked me once again and light-hearted said goodbye. yahoo.gif

And as one can see in this photo, the cleaning was really perfect, because there are no wax residues left, cant-believe-my-eyes-smiley-emoticon.gif  which is why no aftertreatment was required too.

 

J2zIez.jpg

 

This is especially also illustrated by comparing the photos before and afterwardstop.gif

 

dyakXC.jpg

 

UWo24P.jpg

 

baAJUZ.jpg

 

r3i5LG.jpg

 

And here once again a few pictures of both ITs in comparison, where the FUD-IT looks even more filigree than the WSF-IT

 

glWkFZ.jpg

 

sqH9eI.jpg

 

Nevertheless, I think that one can use both ITs, depending at whim and purse. up040577.gif

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Congratulations Manfred!!  The new cleaning method worked out beautifully.  I can't wait to see your insulation foam come to light with the freshly cleaned IT part.

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Thanks Rich for your nice congrats! :worthy:

 

Yep, the IT looks clean as a whistle, as the saying goes. smiley250.gif

 

If one knows how to do it, Ultrasonic cleaning is really easy, and now I have the know-how, and all of you too ...  top.gif&key=e896a02d20fce3e69aff6c90ad2a

 

One either needs sa good equipment, or one has a good dentist with a helpful lab team. top2.gif

 

BTW, the IT already has its SOFI and is ready for priming and painting. up040577.gif&key=327a20a361d18ad6d35cabf

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