Inline Reaction Wheel vs. Inline Advanced Stabilizer

[TheTranceMan]

what is the virtue of even having the IRW in the game if its mass is higher than the IAS and has only half the torque and nearly the same electricity requirement? i recall the IRW having a higher torque value (i swear it was 20), which made them worthwhile, but now it is just a completely impractical part.

tech tree aside (IRW is available one tier sooner, but no other requirements to unlock IAS next) is there some benefit that the IRW imparts that makes it worthwhile? or is this just an instance where the devs overlooked an obvious mistake in the stats?

[sal_vager]

Mass is taken into account when making torque calculations, so the heavier part actually has more oomph

[TheTranceMan]

if that were the case, why are my older SAS-equipped designs so nerfed? why would a part with higher torque be available sooner in the tech tree.

there is no way the mass of the part has any effect on the torque it provides. do some testing and see for yourself

[cantab]

The reaction wheel is just a reaction wheel, while the advanced stabiliser provides SAS functionality, using things like RCS and control surfaces to keep the rocket on course. All command pods and probe cores, excepting the external seat, now have SAS anyway so this is usually moot, but in past releases they didn't. Both parts had to be kept around to avoid breaking old craft.

EDIT: Oops, I was unaware .24 had rebalanced them. So now it's the inline wheel that's outclassed in aspects other than cost.

Edited August 3, 2014 by cantab

[LethalDose]

As you pointed out, you get the basic unit is available earlier on the tech tree. It also cost fewer funds (300 vs 600, IIRC). These are it's primary advantages over the advanced units.

There have been plenty of times in my current career mode where all I needed was the basic unit, and and the additional 0.02 t didn't affect my dV budget, so I saved a few hundred credits by choosing the cheap one without really loosing anything.

I would guess that the torque values of the SAS units were tweaked to differentiate them from each other. The game is under development, so the parameter values of the parts are subject to change from time to time. It sucks that you see it as your old designs being "nerfed" but such is life in alpha/beta/dev/early/whatever release.

Mass is taken into account when making torque calculations, so the heavier part actually has more oomph

Can you explain this statement? I agree with the OP, it makes no sense to say "the heavier part has more oomph".

[TheTranceMan]

as it stands, the IRW's mass and electricity requirements make it a completely useless part and every vessel in my library that had one instantly became un-flyable. i'm just going to edit the part.cfg file instead of redesigning all of the vessels which use it.

chances are very high that any vessel requiring extra torque to be flyable still isn't going to be flyable with a measly 8 units of torque. squad shouldn't have broken that part.

[Taki117]

If we take a look at the Wiki we see that the IAS has slightly less mass, more torque, and uses slightly more Electric charge than the IRW

[Jouni]

chances are very high that any vessel requiring extra torque to be flyable still isn't going to be flyable with a measly 8 units of torque. squad shouldn't have broken that part.

The IRW is actually just as efficient as it was before. You just need to use more of them. The old part generated 20 kN·m of torque for 0.3 tonnes of mass, while the current part provides 40% of that for 40% of the mass.

[Sirrobert]

The weaker one costs half as much funds

So if you're trying to save money, and don't need that much torque anyway, you can put the weaker one on your smaller crafts

[cantab]

chances are very high that any vessel requiring extra torque to be flyable still isn't going to be flyable with a measly 8 units of torque.

Disclaimer: going by wiki values here. For manned craft, you may well be right given the command pods have torque on the same order of magnitude, but for unmanned craft the reaction wheel gives 20 times the torque most probe cores have alone. That's clearly going to make a huge difference to the handling.

[rkman]

The reaction wheel is just a reaction wheel, while the advanced stabiliser provides SAS functionality

No, both parts have ModuleReactionWheel and ModuleSAS in their cfg.

[Claw]

chances are very high that any vessel requiring extra torque to be flyable still isn't going to be flyable with a measly 8 units of torque. squad shouldn't have broken that part.

I am sorry the update messed up your ships. However, I think it's great to have a torque module that fills the gap between the very low end of probe cores (0.5) to the next step of the reaction wheels (20). We needed a part somewhere in the middle that wasn't a pod, and the reaction wheel and advanced stabilizer have been redundant for a few versions now.

just my 2 cents.

-Claw

[rkman]

Mass is taken into account when making torque calculations, so the heavier part actually has more oomph

That does not seem to logically follow from the fact that it is called "torque"; torque is a force, which already involves mass. Might still be true but then it looks like the term torque is used incorrectly.

[DrMonte]

That does not seem to logically follow from the fact that it is called "torque"; torque is a force, which already involves mass. Might still be true but then it looks like the term torque is used incorrectly.

Torque of the part is not directly related to the part mass. It just adds up to the maneuverability of the vessel.

As the mass of the part adds up to the total mass of the ship the "oomph" is less the heavier the part.

p.s.

Reaction Wheel force applies in place where the part is placed.