Huygens' HASI instrument(s) ?

General physics and astronomy discussions not directly related to Celestia
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Post #21by ElChristou » 25.08.2007, 11:28

Cham wrote:Okay, okay, here it is, microphone included ! :P


Cool!
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Post #22by Cham » 25.08.2007, 19:22

AAArrgh !

I've found an ultra-high resolution picture of the top of the real huygens :

http://huygens.esa.int/science-e-media/ ... MG0034.jpg
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Post #23by Cham » 26.08.2007, 20:36

I've corrected most of the errors I made on the model, thanks to the last high-res picture. The four "pads" are now correctly placed (they aren't at 90?° from each other). It was pretty long to do. I didn't expected to build a model like this one at first, since it was supposed to be a simple replacement for the old model from Jack. Now, it's getting pretty accurate, except a few details here and there. I'll rebuild some details I'm not satisfied with.
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Post #24by ElChristou » 26.08.2007, 20:44

Will you add the cd?

One important point in this last doc is the axis of the articulation of the 2 arms... have you noticed?
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Post #25by Cham » 26.08.2007, 20:54

ElChristou wrote:Will you add the cd?

Yet, the CD is already represented as a simple "thick disk" (see my previous pics). I may change it, but I really like the way I made it (it looks cool).

ElChristou wrote:One important point in this last doc is the axis of the articulation of the 2 arms... have you noticed?


Yes, I noticed it. It's not clear enough on that picture and I don't think it's really important. Since I'm very satisfied with the way I made it, that articulation wont change. Anyway, there's a rotation device on my model which let the arm to rotate to the "belt" position, so this isn't a problem. There is no "conflict" with the real thing.
Last edited by Cham on 26.08.2007, 21:13, edited 1 time in total.
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Post #26by Cham » 26.08.2007, 21:05

Here's a preview from the modeler :

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The green arrow shows the least well known part (the gray box). I didn't found enough good pictures of that piece (the three legs in the old model ?), so it's very approximate. Looks cool anyway. The shape of that box comes from some figures and diagrams I've found.

The red arrows shows the pieces I want to change. The "CD" cylinder is nice enough for my taste, but I may change it too, since it's an easy part. A CD without any protection on top of the probe doesn't make any sense to me. Why s it there, without protection ??
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Post #27by ElChristou » 26.08.2007, 22:13

Cham wrote:
ElChristou wrote:Will you add the cd?

Yet, the CD is already represented as a simple "thick disk" (see my previous pics). I may change it, but I really like the way I made it (it looks cool).

ElChristou wrote:One important point in this last doc is the axis of the articulation of the 2 arms... have you noticed?

Yes, I noticed it. It's not clear enough on that picture and I don't think it's really important. Since I'm very satisfied with the way I made it, that articulation wont change. Anyway, there's a rotation device on my model which let the arm to rotate to the "belt" position, so this isn't a problem. There is no "conflict" with the real thing.

The way instruments are deployed on a planetary probe is not really important? Then what is important? :lol:

Cham wrote:The green arrow shows the least well known part (the gray box). I didn't found enough good pictures of that piece (the three legs in the old model ?), so it's very approximate. Looks cool anyway. The shape of that box comes from some figures and diagrams I've found.

The red arrows shows the pieces I want to change. The "CD" cylinder is nice enough for my taste, but I may change it too, since it's an easy part. A CD without any protection on top of the probe doesn't make any sense to me. Why s it there, without protection ??


Indeed Cham I cannot see your point...
You use "cool", but what does that mean in the case of a model based on a real artifact? Seems you are doing a StarWars stuff...

IMHO, if one want to do an historic model, there is no point in questioning the choices done by several dozens of engineers. The CD seems odd to you? dig the topic then do it as it was, no more and no less...

Don't you see such a model loose all it's interest if you begin to change things depending on your taste?

See those 2 arms; on your model one can understand they are deployed vertically when in reality the angle is predetermined by a fixed piece, and the rotation is done almost on the horizontal... Even if you don't have the exact detail of the system, at least try to do something that will represent the real rotation!

Hope you will change your mind... :?
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Post #28by Cham » 26.08.2007, 22:24

ElChristou,

I'm doing some approximations on the model. I don't intend to build every small details, down to the smallest scale. So I have to do some compromises. All the features are on the model, even the CD is there, while shown as a simple cylinder (as I said, I may change it anyway, since this is easy to do). The arms are deployed in the right position and angle. Only the mechanism isn't exact. So what ? Nobody will notice it (except the compulsory perfectionists). And yet, that model is MUCH more accurate than the old one we already have. Only some small parts aren't.

If you don't like the model, then use the old one instead, or better ; make your own.

Sheesh ! :roll:
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Post #29by ElChristou » 26.08.2007, 22:31

Cham wrote:...If you don't like the model, then use the old one instead, or better ; make your own.


H?©h?©... why I was expecting that?
Too bad you don't see the interest of an accurate model... (and I'm not talking about details)
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Post #30by Cham » 26.08.2007, 22:38

ElChristou wrote:Too bad you don't see the interest of an accurate model... (and I'm not talking about details)


ElChristou, the model IS accurate. But not to the same scale as you want, that's all. Even your models aren't accurate to some scale. All models are just approximations of the real things, with some compromises here and there. My model is WAY accurate enough to be shown in the classroom, or to do some presentation on space exploration. Who will really care about the arms mechanism, or this and that detail, as soon as we can understand what the probe is actually doing ?

Really, you're exagerating, about that articulation mechanism.

Of course, you are free to consider this model as a StarWars model, full with laser guns and deflection shield if you wish. :P
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Post #31by ElChristou » 26.08.2007, 23:11

Cham wrote:
ElChristou wrote:Too bad you don't see the interest of an accurate model... (and I'm not talking about details)

ElChristou, the model IS accurate. But not to the same scale as you want, that's all. Even your models aren't accurate to some scale. All models are just approximations of the real things, with some compromises here and there. My model is WAY accurate enough to be shown in the classroom, or to do some presentation on space exploration.

Again, it's not a problem of scale or details; I'm talking about a cinematic system (in the case of the "arms"). Your are mixing accurate and detailed... Your model (state shown above) is well detailed but (in the case of the arms and CD) not accurate...

Now concerning my models (if you want to compare), I try to reproduce those cinematic system as accurate as possible. As example, the instrument boom of Voyager can be stowed without problem (the attach system is here). More recently, the LEM gears; the system is more complex than it looks. If you look closely to the pre-realize I've done, the articulations are represented by simple cylinders (no details), but those cylinders are positioned the way they should to achieve the complex rotation of each elements of the gear from stowed to landing position...

Again, no question of details.

You have here a very nice and detailed model, perso I think it's a pity to not push it bit more. That's all.

Cham wrote:Who will really care about the arms mechanism, or this and that detail, as soon as we can understand what the probe is actually doing ?


Any person really interested in this probe I guess...

In all case, Cham, I've said what I think I had to say now I won't discuss more the topic. It's your model, you do how you feel, for me no problemo.
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Post #32by Cham » 26.08.2007, 23:15

As I said, use the model in your SF sceneries, if you wish. Do you want me to add some guns, or a cockpit ? :wink:

ElChristou wrote:Any person really interested in this probe I guess...


Well, as far as I know, I am interested in this probe, but not in the mechanism details...
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Post #33by ElChristou » 26.08.2007, 23:35

Cham wrote:
ElChristou wrote:Any person really interested in this probe I guess...
Well, as far as I know, I am interested in this probe, but not in the mechanism details...

ElChristou wrote:Any person really interested in this probe I guess...


By "really" I mean someone interested not only in a pretty picture...
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Post #34by Cham » 26.08.2007, 23:47

ElChristou wrote:By "really" I mean someone interested not only in a pretty picture...


Now, you are condescending, by implying that I'm only interested in pretty pictures.

Do you think the old model is "accurate" ? Certainly not, it's a gross representation of the historical event. And yet, it's still a good model to show the historical event itself. Do you think the usual rendered models shown in many presentations on the web are accurate ? Of course not, but it's still better than our old model, to show some of the probe operations and instruments. Do you think my model is more accurate than any of them ? Yet, it can show more stuff than all the models found on the net. With my model, I can show the usefullness of "blades" and small "wings" under the probe to stabilize the descent, I can use it to show how engineers are putting some "useless" metallic blades, to balance the probe, I can use the model to show the two parachute boxes (and why there are two parachutes), the CD as a signature, the thermometer and pressure measuring devices, etc. But do you think the actual mechanism to deploy the arms are really interesting ? I think NOT ! Only the arms themselves are interesting, not their articulation. So "accuracy" is still a matter of details.
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Post #35by ElChristou » 27.08.2007, 00:23

Cham wrote:
ElChristou wrote:By "really" I mean someone interested not only in a pretty picture...

Now, you are condescending, by implying that I'm only interested in pretty pictures.

As always, you take things as personal attacks when it's not the case.

Think about it; if something is wrong on a model which is supposed to be detailed/accurate (I merge the two terms because you seems to not get my point), in the present case the way arms are deployed, why trusting any others details?
More, what about now another model, just before opening of the parachutes? the top protection is not present anymore, but the probe is still attached to the shield. How will you present those arms?
Perhaps you will "add" hypothetical motors inside the body to explain the rotation of your present articulation to allow the arms deployment on the vertical?

So resuming, if nothing can be trust, only remain a pretty picture.


Cham wrote:Do you think the old model is "accurate" ? Certainly not, it's a gross representation of the historical event. And yet, it's still a good model to show the historical event itself. Do you think the usual rendered models shown in many presentations on the web are accurate ? Of course not, but it's still better than our old model, to show some of the probe operations and instruments. Do you think my model is more accurate than any of them ? Yet, it can show more stuff than all the models found on the net. With my model, I can show the usefullness of "blades" and small "wings" under the probe to stabilize the descent, I can use it to show how engineers are putting some "useless" metallic blades, to balance the probe, I can use the model to show the two parachute boxes (and why there are two parachutes), the CD as a signature, the thermometer and pressure measuring devices, etc...


Precisely it's why I think it's too bad you don't push a bit more this nice model.
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Post #36by Cham » 27.08.2007, 00:40

ElChristou wrote:Think about it; if something is wrong on a model which is supposed to be detailed/accurate (I merge the two terms because you seems to not get my point), in the present case the way arms are deployed, why trusting any others details?
So resuming, if nothing can be trust, only remain a pretty picture.


What a clown you are ! :P

ANY model have some bits which aren't accurate. Even you own models contains some approximations (I even found an error on your shuttle with the cockpit). So how can I trust all the rest ? Really, this is ridiculous. With your perception, I shouldn't trust ANY model, from anyone. Geez, come on, it's just about "models", and nothing more. You are taking all this way too seriously.

I can't reach perfection in modeling, therefore I accept some approximations. In the case of the model I'm working on, I accept some "imperfections" like the arms mechanism (which isn't in conflict with the real thing, since I can close the arms along the "belt"). This is my choice. Too bad you don't agree with it.

Now, you have me convinced to stop posting anything here, on any model I may be working on. You are so discouraging with your compulsory perfectionnism, that this is my last message ever about any models creation.

:x
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Post #37by ElChristou » 27.08.2007, 00:52

Cham wrote:...Now, you have me convinced to stop posting anything here, on any model I may be working on. You are so discouraging with your compulsory perfectionnism, that this is my last message ever about any models creation...


Too bad, wasn't the goal... :(

BTW, you will be pleased to learn that a new shuttle is on work with a new cockpit! (was one of the reason why I never released the payload open)
Now, indeed no idea when it will be ready :?
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Post #38by Cham » 27.08.2007, 02:44

I've found a physical argument against my own mechanism for the arms : Titan's atmosphere will produce a strong resistance and a mechanical torque on the arms, and may destroy the mechanism. So I don't have much choice, for the love of physics, I must change that part on the model ! :?
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Post #39by ElChristou » 27.08.2007, 02:59

Cham wrote:I've found a physical argument against my own mechanism for the arms : Titan's atmosphere will produce a strong resistance and a mechanical torque on the arms, and may destroy the mechanism. So I don't have much choice, for the love of physics, I must change that part on the model !


Just note that mine was also a physical argument, you couldn't pack the probe with your articulation!

But seems it wasn't enough, you had to find something else to reconsider... :roll:

BTW, next time try to keep your insults for you...
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Post #40by Cham » 27.08.2007, 03:03

ElChristou wrote:Just note that mine was also a physical argument, you couldn't pack the probe with your articulation!


Not at all ! I already said it before. My mechanism was able to fold the arms along the "belt" of the probe, exactly like it is on the pictures of the real thing (you don't see it on the model pictures given above). That wasn't a problem. Now the friction against the extended arms would destroy my mechanism, with its rotation axis set in the horizontal position. So I need to change it.
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