Wednesday, September 9, 2009

Physics and the RX-93

Alright, I've been kind of dreading making this post because of the backlash I may (or may not) receive but I'm going to do it anyway. Over at the Gundam Australia boards Sonar/Tonzo made a comment about my attention to realism and the physics of these imaginary machines. I've done this more than once refering to the wing binders of the Sinanju and the weight of the Infinite Justice being supported by such thin ankles. I mean look at this!



These are supposed to support just under 40 tons of weight each?! One crack at the area where the red line is and this thing is going down like a... uh... 18m tall walking tank... >_> *cue nervous look*

I'm at it again today with something that has really been nagging at me. The RX-93.



Just mentioning this I'm sure a lot of you know where I'm going with it. All stats are from MAHQ.

Dimensions: overall height 23.0 meters; head height 22.0 meters
Weight: empty 27.9 metric tons; max gross 63.0 metric tons

Big. We all know that.

Propulsion: rocket thrusters: 4 x 18300 kg, 2 x 12300 kg = 97800kg at full burn. 26 verniers (which I understand to be minor stabilizing thrusters. I have no idea what 'apogee motors' are. I know what an apogee is but the motor idea... that's lost on me.)

Sinanju is 128600 kg for the record. I previously said that each wing has an output of 64300kg of thrust per wing which may not be the case. The thrust output for the waist and leg thrusters isn't listed, so if the total thrust is 128600 kg including all the burners than the wing output is probably less than 64300.

Right. Who cares. Imaginary machines. But it's the principle of it! If you're going to make the numbers and put them out there, make the numbers right!

OK putting those numbers off to the side... I want to talk about the design on the RX-93 and how it would work within the rules of physics for this reality.

I don't have any problem with the Nu Gundam by itself but when I see it with the fin funnels attached I have a bit of trouble suspending my disbelief.



Look at that. Shouldn't this thing be toppling over? Obviously, my main issue is where the supposed center of gravity/mass would be with a suit like this. With the thrusters distributed symmetrically around the suit itself, it would take a massive amount of computations and thruster control to make this thing maneuverable. I know it's a prototype suit but still... the principles...

We can have to assume a couple of things first for lack of more detailed information:

1.)All 6 funnels have the same weight and mass as each other.
2.)The suit itself is built with even weight distribution with the center of mass running somewhere along the central vertical axis.
3.)The weight of the rifle and shield balance each other out.

The weight and position of the those funnels would cause the whole center of mass to swing outside of the suit, towards the shield arm. Provided that the Nu has even thrust from all burners it would be spinning left constantly because of the extra weight.

Now launch a couple funnels... the weight and center of mass change again, unfold them but keep them docked and the center of mass changes yet again! Imagine it in this configuration.



Better than the conventional one but still... how can you balance this thing? It's constantly fluctuating. The on-board computer must be going crazy trying to compute how much thrust is needed from each thruster independently just to make this thing go in a straight line. Never mind the psycoframe system and the processing drain that must take... it bugs when when I think about it. The only way it works for me is with another set of funnels on the opposite side, in the same configuration, to balance it out.



But that still won't change the fluctuation issues. And don't get me started and the HWS version!




Makes my head want to explode. The strain that shield thruster must put on those thin elbow and shoulder joints... my goodness. I don't know, maybe those future materials can handle it... but still... it bugs me. I take my Sci-Fi machines seriously! and I can suspend my disbelief for a lot of things.

U.S.S Enterprise? Ridiculous ship design. Well, until they got to the E-Type and after but whatever. I can let it go.

X-Wings, A-Wing, Y-Wings, hell even the B-Wing. Star Destroyers... now you're talking. And don't get me started on the Macross Valkryies... I mean... just... the pinnacle.

So I'm sticking with the Hi-Nu as the superior design all around. (Yes. With this colour scheme.)



There are no stats outside of height and weight so I can't pick on it. Symmetrical, smaller, more efficient, good thruster location and balancing and most important for me... believable. As much as anyone can believe in these machines but... you wouldn't have read this if you didn't want to believe in it somewhat right?