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747 Orbiter SCA Mounts Study


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I knew you wouldn't be able to help yourself! ;-)

 

They look awesome!!!

 

Molding would be a snap if you make the vertical mounts and forward braces one part, then the two different inboard braces separate. I'll assemble them on the model. I plan to cast them in white metal or hard resin.

 

Will the tongue brackets that the braces bolt to be in the side braces, or will I need to just make them from sheet styrene?

 

Tracy

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  • 2 weeks later...

Hi Tracy, sorry for the delay, I was having a little trouble matching/aligning some views for the front mount.   And the pull of the Tomcat was too strong (was kind of working on that, too, to prevent burnout :rolleyes:

 

I was trying to match the rear view line drawing with the sideview and couldn't get them to match.   The 4.46 deg.  mentioned here threw me off.

 

O9LRHrb.jpg

 

 

 

DxvsgVK.jpg

 

 

NnBUZzv.jpg

 

 

XnQgOj6.jpg

 

 

FP0viSR.jpg

 

 

Until i found a portion of the blueprints showing the ferry position and overlayed the rear views on it.   It's clearer to me now.   The front mount can kneel lower that what's shown in the rear view.   

 

 

HjHEH1J.jpg

 

 

BTW, your question about the tongue brackets -- they'll be there when I separate the parts.   They'll be really tiny, though -- hopefully they'll still be recognizeable. 

Edited by crackerjazz
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No worries... I'm not one to throw stones in glass houses. I bounce around project to project as well. Keeps the project fresh when you can walk away from it and start fresh without completely leaving the hobby.

 

Looking forward to seeing what you come up with in the forward mount.  I am extremely glad you have your own 1/100 747 there to reference from - cuts down on the difficulties of explaining details via text. ;-)

 

Tracy

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  • 1 month later...

Hi, just getting back to this, sorry.  Project isn't dead ...... work is getting in the way of hobby-time   :)

 

d2Y0NCo.jpg

 

 

mh4Powl.jpg

 

 

urne5zA.jpg

 

 

JBDWwZQ.jpg

 

 

7pi2M0H.jpg

 

I'm mirroring both sides for now but will correct later.   Only the starboard side should have the knuckles (I wonder why).

 

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Looking terrific! The drawings as a guide are awesome. How well does the shape, and diameter of the Entex 74 fuselage match the drawings? Do they match, or do you expect any post adjustments after the modeling is done?

 

When I get home off my current trip, I'll share the 3D printed additions I already have for this project:

Shuttle tail cone

747 engines

Vertical tip stabs for the horizontal tail surfaces 

Kreager leading edge flaps, and trailing edge flaps.

 

Now if we can get Hotdog to rescale the top side shuttle decals for the Tamiya kit!  ;-)

 

Tracy

 

currenly, l've been the most motivated with my Large Starship Excelsior scratch build.

Edited by Vidar_710
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Compared to the drawings, the Entex/Doyusha height at this point is off by a few mm --  could be the drawings or the kit itself : (     I'll have to measure the width at the attachment points of the forward mount and make adjustments to the 3D model if necessary.

 

ViOivDc.jpg

 

 

WEmWAgq.jpg

 

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  • 3 weeks later...

For the longest time, I thought the forward mounts actually attached to the fuselage right into the aft window ports in the dome. Looking back I discovered why... The old 1/144 scale Revell Shuttle/SCA kit I built as a kid made that the gluing point for the forward mounts. LOL

 

Tracy

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1 hour ago, Vidar_710 said:

For the longest time, I thought the forward mounts actually attached to the fuselage right into the aft window ports in the dome. Looking back I discovered why... The old 1/144 scale Revell Shuttle/SCA kit I built as a kid made that the gluing point for the forward mounts. LOL

 

Tracy

 

I'm building that kit now and left those windows open for the same reason, looks like I will fill them and make new mounts.

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  • 2 weeks later...

This one, too, hehe.  Really appreciate the kind words.    But I was getting cross-eyed and all trying to align the drawings.   And my 3D touch must be fading --- I couldn't get some stuff right.     Also I'm really worried about the parts -- being ant-sized -- if they'll actually pull through the printer with details intact.    I'm just worried it will all come to nought.    A little break should do some good.   But thanks for the support, guys.    

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CJ,

I have no problem with you using a little creative licensing to adjust the parts to fit the model. For all we know, both the model and the drawings could be off.

 

As far as your concerns about it being printable... I think you'll fine it'll be OK. Amongst the other 3D printed parts I've had made for this project, the most intensely detailed is the engines for the 747. Each stator and vain in the N1 Fan section, as well as the turbine section seen through the exhaust is beautifully printed separately. These mounts in 1/100 scale should be awesome... 1/144 or smaller is anyone's guess.

 

The diameter of the forward mounts shouldn't be a problem, and their strength is moot due to my plans to mold and cast them in hard resin.

 

I agree... stepping away and coming back with a fresh perspective is always a good thing. Being an airline pilot, I have the opportunity to be forced in to doing just that. It has been instrumental in regards to my Large scratch-built U.S.S. Excelsior NX-2000 project. I'm in full steam on that, getting close to finishing the masters for vacuum forming new clear hull parts (now that my large vacuum for table has arrived.)

 

Tracy

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  • 3 weeks later...

CJ,

Do you have an expected measurement from the crest of each aft mount. I'm going to cut out the shapes and scratch built the recessed panels where the ET, and the 74 mounts insert into their sockets in the belly of the shuttle.

If you don't want to do the forward mount, I think I can manage to scratch build it. Let me know when you're ready to submit the  aft mount parts to Shapeways, and I'll go ahead and get them printed so I can't get them into clay and rubber for casting.

 

Tracy

Edited by Vidar_710
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Hi Tracy,  no, don't scratchbuild it.   Just need to motivate myself and focus on one project at a time.   And there are some difficult aspects of the 3d-modelling that bog me down just worrying about them such as when I'll finally have to break them apart -- and  I seem to get overwhelmed.   And those irregularly-shaped forward mount fairings -- how do I model those?  I really have to take it one step at a time -- a scrum board might help.  Ok, CJ, take a deep breath, exhale slowly and let's begin!  We can do this!   

 

Crest to crest =  51.94mm

 

Igd6u2e.jpg

 

Actually, don't start boring holes into the shuttle's belly just yet.   I have to measure the fuse's width at that spot as it might not match the drawing's 51.94 stance.  

 

dJ6Gl5e.jpg

 

ZaBiQ3f.jpg

 

Need to leave for work but let me get back to you tonight.  Just need to do some more measurements on the kit's fuse.

Edited by crackerjazz
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OK, I'll hold off. I finally found a guy that has the option of early or late Shuttle paneling decals for the top of the Tamiya kit... ordered the late version. I like Hotdog's bottom set in combination with this set using the best characteristics of both. The open panels where the connections are made to the ET/747 are included, and very nicely done.

 

Having everything I need to start has lit a fire under my arse. ;-)

 

Tracy

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So that's 46.83mm on the model.    If we follow 51.84mm crest-to-crest the base of the mount would be hanging too low on the sides.   We need to follow the 12.69 mm distance from the top (as viewed from the side).   

 

Just curious, could you measure the open panels (center to center) on the decals for the rear mounts?

Edited by crackerjazz
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Fantastic 3D-Modeling on a very high level, which proves that you seemingly master your Solidworks playfully, simply awesome! hi.gif

 

I wish I could do that too ... hmmm.gif

Edited by spaceman
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CJ,

I'm currently on day one of a 4-day trip. I'll measure the graphics, and even post pics -if you want- when I get home. I took photos of the Atlantis hatches while visiting the Northern Smithsonian in D.C. They really did an awesome job recreating that detail.

 

Tracy

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  • 3 weeks later...

Sorry for taking so long. Days between trips too short, and still in "Full Tilt Boogie" on the U.S.S. Excelsior NX-2000 project..

 

Here's a measurement on the decal for the receptacle ports for the mounts. It's showing 1.33cm apart for the mains. I'm not just going to apply the decal to the belly of the shuttle. I am going to cut the panels in for their recessed characteristics, and use these graphics where they are suppose to go. I'm also gonna make the doors as well, then apply the graphics to them. Sooo, this distance is not in stone. I'll place them where they need to be for the 74 to meet the shuttle properly.

 

0815172317-1.jpg

Edited by Vidar_710
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Guys, this is some amazing work on these mounts. Super super impressed.

 

Vidar, I do want to note one thing though. in that last pic you posted, the caliber to my eyes looks like it's saying 1.330 inches, not CM. Is that "in" not what the scale is set to? Just an observation. 

 

Can't wait to see all this come together.

 

Bill

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oooooooOOOOOPS! You're right! and when you're right, you're right, and you ARE right!

 

In my defense, I finally remembered to do this after getting home from my last trip at 3AM. I was spent!

 

Here it is in metric...

0816171647-1.jpg

 

My pic I took under Atlantis at the Smithsonian

 

0325171105.jpg

 

Like I said earlier, these recesses will be cut in, and the doors will be scratch from thin styrene with these graphics applied to them.

 

Tracy

Edited by Vidar_710
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Thanks, Tony, Manfred, Bill!  Tracy, thanks!  Hmmm....that's a huge difference from our 59.4 crest-to-crest measurement : (     Can you try marking 59.4 on the shuttle's belly?   The decals must be right so where did we go wrong?    34mm seems too close for the main mounts to sit right on the Doyusha kit but I'll check the fuselage tonight.

Edited by crackerjazz
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On 8/15/2017 at 10:30 PM, Vidar_710 said:

Sorry for taking so long. Days between trips too short, and still in "Full Tilt Boogie" on the U.S.S. Excelsior NX-2000 project..

 

Here's a measurement on the decal for the receptacle ports for the mounts. It's showing 1.33cm apart for the mains. I'm not just going to apply the decal to the belly of the shuttle. I am going to cut the panels in for their recessed characteristics, and use these graphics where they are suppose to go. I'm also gonna make the doors as well, then apply the graphics to them. Sooo, this distance is not in stone. I'll place them where they need to be for the 74 to meet the shuttle properly.

 

0815172317-1.jpg

 

That distance you are measuring is between the fuel & oxidizer inlet ports - not the structural mounting points.  Those small circles in the upper outer corners of the decal are where the SCA (and ET) connect as a load bearing point. 

 

edit: see the callouts for "ORBITER - EXTERNAL TANK AFT ATTACH POINT" on the drawing at this link:

 

http://web.archive.org/web/20001002192048/http://www.spaceflight.nasa.gov:80/shuttle/reference/sodb/2-5a.pdf

 

I found another drawing that shows the attach points are +/- 57 but no units are given.  I doubt that dimension is in inches because I know the doors are 50" x 50" with 4" radiused corners, making the attach point spacing closer to 200"

 

 

 

Edited by habu2
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I think I may have found the problem, The decals sent may be in 1/144 scale. I've sent the maker an email to confirm my findings. Another thing is, your measurements may be incorrect as well. I took some picks of the 74 fuselage and a pick of the real SCA to corroborate my findings..

 

1. The decals are defiantly too small

2. Your measurements would put the mounts bases almost down on top of the passenger doors, so... too wide.

3. Using a image off an SCA, I extrapolated that the mounts are about a "half door" high above the actual door positions. This would place the base of the mounts where they attach to the fuselage at, or just a tad above the raise panel line that runs longitudinally down the fuselage just above all the doors, making the distance between the ports about 49.5mm.

 

Defiantly decal too small a scale.

0817170824.jpg

 

Real SCA mount posit. half a door above PAX doors.

0817170806-1.jpg

 

Measurements, Top: CJ's measurement, Middle: decals measurement. Bottom: my measurement (raised panel line to raised panel line)

0817170804a-1.jpg

 

Oblique angle. Take note CJ how far down to the door the mount would be with your measurement.

0817170804-1.jpg

 

I think for the purpose of this 1/100 scale project, that the best measurement for separating the tips of the "balls" or receptacles in the belly that fit into the shuttle's panels is 49.5mm.

 

Thoughts CJ?

 

Edited by Vidar_710
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