Useful A.S.A.S Units.

[Whirligig Girl]

The A.S.A.S., Large, and the Inline Advanced Stabilizer do the same thing as the Inline Reaction Wheel. The A.S.A.S. Large is also hollow, so there's no possible way it could create torque from this ring. I know the MEchJeb autopilot is not going to be put in, but maybe a simple flight control unit could be added built into the A.S.A.S. units. I'm thinking of MechJeb's Smart A.S.S., but more limited. It would place the A.S.A.S. units further in the tech tree, and a new model for the Inline Reaction WHeel Large would be needed, and KSPX has one.

[Luis]

I agree, it basically makes no sense that we have an SAS that will hold the current vector, but not orient us automatically to prograde or normal. I'd be happy for it to be high up the tech tree, expensive and use a lot of electricity, but it should be there as an option.

[Red Iron Crown]

Just a nitpick, but there's no reason a reaction wheel can't have a hollow center.

[Kasuha]

Just a nitpick, but there's no reason a reaction wheel can't have a hollow center.

There is. Hollow center means less matter in the wheel and subsequently less inertia. Of course reaction wheels are usually not 2.5 m in diameter, too. More like half a meter tops. So we can say that the ring is just casing and the reaction wheel is that small yellow cylinder on the side.

Also it's not true that it is not possible to put things inside the ring. You can clip a whole lot of things inside. It's not much better than clipping them inside any other part, though. They are a bit more visible but not a bit more accessible.

[Red Iron Crown]

There is. Hollow center means less matter in the wheel and subsequently less inertia.

That doesn't preclude hollow reaction wheels. In fact, a hollow centered wheel would have greater polar moment of inertia for a given mass.

[Kasuha]

That doesn't preclude hollow reaction wheels. In fact, a hollow centered wheel would have greater polar moment of inertia for a given mass.

But not for given volume.

[Red Iron Crown]

But not for given volume.

You're shifting goalposts. The OP said "The A.S.A.S. Large is also hollow, so there's no possible way it could create torque from this ring.", which is false, and what I was responding to.

Plus, if you have a given volume and mass, a hollow wheel will have greater polar moment of inertia. Just make the hollow ring denser. Reaction wheels concentrate as much of their mass as possible at the outer diameter to maximize polar inertia per unit mass.

I bet if you were to open one of those reaction wheels pictured in your post, you would find that the reaction wheel itself is hollow, with the drive mechanism and bearing in the center. Or at the very least, with a heavy "doughnut" of material at the edge with a lightweight structure connected to the center spindle, like a toy gyroscope.

Edit: Poking around google images, it seems that most reaction wheels are cup shaped, with most of the mass concentrated in the outer shell, with a much lighter disc at one end connected to a central spindle. The motor and bearing are placed inside the cup. I guess the mass of the bearing is a factor, a bearing for a hollow ring would be heavier than a smaller central bearing.

Edited March 15, 2014 by Red Iron Crown

[Kasuha]

When we're talking about the ASAS model, then I am pretty sure the reaction wheel component in it is the small yellow/orange ring, the block is meant as control unit and the rest is casing. Someone posted a picture of what appears to be the inspiration of the whole part just recently and you can see that there is no room for anything huge rotating around it.

Edited March 15, 2014 by Kasuha

[Red Iron Crown]

I assumed the yellow disc was the drive mechanism and the reaction wheel itself was inside the ring, which is noticeably thicker than the Saturn instrument ring.

Kind of a moot point as the reaction wheels aren't simulated to that degree anyway, they just apply force to the craft as required.

[purpletarget]

The ASAS model was from an earlier version where the part wasn't a reaction wheel, but simply a set of flight computers to allow SAS functionality (And yes, based on something similar to the pictute, which is all guidance and telemetry gear. Now that functionality is included automatically in all the command pods.

The part has been re-purposed as a reaction wheel...however the skin of the model has not been changed yet to reflect that. I'm sure they'll get around to it...along with all the other parts that need attention, and a 3D modeler/artist to work on it....I seem to recall a job posting being advertised a short while ago.

Remember in KSP, if you try to do real science to stuff in game...you're going to have a bad time.

[Whirligig Girl]

The thing is, the A.S.A.S. module large is clearly a computer ring like that of the S-IVB rocket stage. It previously didn't provide any torque, but now it does and it makes no sense for a computer to provide torque, especially as much as it does when it's in the small box. The KSPX model actually makes sense for a large Inline Reaction Wheel. So I think the models whcih were once called A.S.A.S. Module but are now torquwheels should be given flight computers and a new 2.5m model should be made as a reaction wheel.