LADEE Model anywhere ?

[sreinmann]

I remember discussing those issues with you before Eric, and they remain valid concerns. The model I'm referencing appears to be an earlier version of one prepared for many of the "artists concept" drawings. Early version that is because, the ACS motors are incomplete and the instruments on top of the radiator panel are completely fantasy. Meanwhile the solar arrays are consistent with the artist's pics, and again, not consistant with the clean-room photos.


Still, I'm pleased with my guess-work and the first prototype came out looking better than expected. I'm colorizing my parts and working on my first draft now, making notes for the instructions, yada yada

Oh, by the way, if you think measuring off the instrument node's taper has been fun, wait till you try to guess the angles of the Star Trackers!! If you've come upon anything leading you forward in that area - please share! That's one spot where I'm swinging blind for the fence.

[Jadriancz]

Here is a link to 13 other nasa models if interested..
DISCOVERY :::Education ::: Spacecraft Models

[ETG]

The star trackers were easy. A simple four sided pyramid, without any weird angles. On my model, I am going to leave that little corner at the base away,
as it might be too small and too fiddly.
I have been working on the tapered octagon and I think I got it now. As soon as I figure out how I can post pictures here I shall do so. Maybe via Photobucket,
using the standard 'brackets' - img - 'brackets'....? [img] I'll give it a try.

______
Erik

[ETG]

Here's what I got, thus far.
By now, what you see here is even less detailed than what I have in front of me now, printed by a professional print shop.
I have made more additions and improvements. Right now, I think I have about 90...93 percent of all the parts - and details - drawn.
The next print and build will also be the final one, and I shall take pictures for the instructions.

It's a small model but the more I work on it, the more parts I need to make....... ;-) It's a little devil. Lots of parts and many of those are small.
Just to make your lives a bit easier....! ;-)

_____
Erik.


A bit rough, but it works. Once I am satisfied it's just a matter of copy and paste onto the final product.

[spacecraftcreator]

Thanks Erik.....I am following this with a high level of interest.

[sreinmann]

Nice looking Erik. I think you're going to beat me to the download page! I 've gotten hung up in my prototype redesigning instruments, rebuilding, redesigning, rebuilding. Ugh. Then work-life stalled me the last couple days. I've Saturday to play catch-up though I think.

I need to post some pictures, its fun to see how close we are both coming and how my novice mind approached some of the problems you've seen your way through more clearly. My scale at 1/25 is definitely larger in size than you've laid out. Like I mentioned, I based mine off of a poorly written press release. I think it will be tough for me to resize my boxes though compared to how you laid out yours. What bus dimensions did you settle on then?

[ETG]

Beat you to the download page? Hmmmm...... I still have to build the final version, take pictures and make the instructions. A couple of months of work,
I guess. I'll be busy for a while. ;-)

Also, I may have to redraw certain parts. For the life of me, I can not figure out what the exact size is of the tapered panels, on top. I am quite sure they
are as high as the rectangular panels, but if I make them the same height, the solar cells won't fit the way they do in the pictures. I'll have to do some
more research.
The size of the large structure was determined by comparing known factors, such as the width of the solar cells and the height of a technician, standing right
next to the satellite. Of course, there was a relative large margin of error. According to several calculations and guesses, the width of the structure should be
around 56 mm in scale 1:20, measured at the flat sides of the panels. On my model, it measures about 58 mm. Something that can be easily fixed once I
prepare the sheet for the PDF file. Simply by changing the DPI (dot per inch) to get the model to the proper size, when printed.
On the other hand, nobody can check the exact size anyway and by now, the real hardware is laying scattered all over the Moon in a thousand pieces.........

When your model in scale 1:25 is larger than mine in scale 1:20, one of us must have made a mistake......... ;-)
Most websites mention the wrong size. I've often seen numbers like 2.4 m tall and 1.85 meters square. Well, in that case, the technicians working on the
satellite must be well over 7 feet tall....! I don't think so.........
If the solar cells would be 10 cm x 6 cm, each panel would be much larger than can be seen in the pictures.
And from what I could make up out of the pictures, my best guess is that the type of solar cell used is the ZTJ Space Solar Cell, advanced triple junction.
Sizes like 8 x 4 cm are often used, although custom sizes are available.

And If I made a mistake that requires me to redraw most or all of the larger parts, I will do so.
It just takes time, that's all.

__________
Erik

[sreinmann]

I see what you mean about the overall height as compared to a person. My draft side panels (the propulsion and payload modules) are 6'4" by themselves that's clearly not right. I think I like your dimensions better once I rescaled mine.

You know, as for the instrument module's angle, you mentioned trying to fit the solar cells. From what I can tell from the clean-room images even the one attached here, the upper module appears to have cells of a different size than the rest. I had no notion of cell size, so I just built my sizes according to their arrangement/layout and number. My upper panel is therefore the same height as the side panels. I hope that helps you settle on and be confident of the angle you've chosen.

Anyhow, here's where I'm at so far. My UVS cylinders are too small, easily addressed in the next build.

[ETG]

Here is my constructive comment. (NOT meant to be negative in ANY way, let that be clear !!)

I decided to make new parts and adjust older ones. The tapered part is now much better. I decided to make the panels of the upper part as high as the rectangular panels,
and I think I got it right, this time.
Talking about redrawing........ I'm afraid you will have to redraw the instruments all over again and make them a LOT smaller, especially the LDEX camera !
That one is WAYYY too big. On my model it's half the size of your camera, maybe even smaller. You will also soon find out that you will have a big problem placing the star
trackers. Where are you going to put them? The instruments on top are all too big,
so that problem needs to be tackled, first !
The gold colored instrument with the coned opening, is also slightly too big. I used the solar cells as a ruler. The large cells are 8 x 4 cm, the smaller ones on top are cut
in half, slightly smaller, actually, and are 4 x 3.5 cm.

Also, the colors you are using is not quite accurate. At least, not if you are going to render it in "flight" configuration. I always draw my rockets and satellites the way they
look during launch and when deployed in space. I see that some of the instruments on your model are black and gold. Well.... you should know that those instruments are all
covered in protective blankets, which will be removed just before launch, or, in most cases, just before the nose cone closes for good. The instruments you made black, are
actually bare aluminium. And some of the gold colored ones are champagne-gold, underneath.
This is very important to remember if you want to redraw or recolor the parts. You must decide to render the satellite in flight modus, in space, or in clean room modus, on Earth.
I know, all that contrast in black, gold and silver gives the model a nicer look, but alas.....once in space the satellite is a lot less colorful.

You can tell if a cover or a bundle of wires are there to stay or if they will be removed before launch. If they are hanging loose, if it looks flimsy, if it is not connected firmly
to the satellite, it most probably is not flight hardware and should not be rendered on the model.
Not always easy to spot, but worth the effort. I struggled with it since the day I started designing paper models ! ;-)

It is also funny to see how we designed some parts in the same way, and others are totally different in design.

You could try to leave the "bottom" of the instrument boxes away. I glue them with wood glue or paper glue so it will be glued firmly to the main structure, despite the small
surface (very thin rim). And the part will sit so much nicer on the model.

I'll post some pics soon to show you my second test model.

One last tip: do not over-complicate parts, especially the small ones. I design my models to be printed on 200 grams paper, and really tiny parts will prove difficult or even
impossible to fold and glue. The paper may delaminate or the ink will come off. Annoying stuff like that.

More pics later.

_________
Erik

[sreinmann]

No offense taken at all Erik! I really find your comments and progress helpful and I hope others do too. I'm learning a lot by designing models (this now my second design). More than I've learned after building (only 13 on my shelf) what others have created.

I agree my LDEX and the Medium Gain antenna are too big. Thought I had it right when I measured off of one of the pictures, comparing their ratio to the length of a side I'd already settled on, but once modeled it is clear that the scale is off. No harm, send it to the workbench to test varnish techniques before letting my 3 year-old play space-aliens with it.

I don't think I'll have a photorealistic model in the end. I don't have the skill you have in that area. Like the solar cells, Different blue tones are not realistic, but I like it, so I'm ok with that. This isn't a fantasy piece though, so like you, I'm going to try to be accurate as we can given our limited resources. And that means that I'm going to learn a lot too! The wiring bundles for instance was something I assumed would be there after testing in the clean-room.

I really am looking forward to keeping up with your progress, and I encourage anyone's comments! How can I be offended? :salute: