Jump to content

How should Reaction Wheels work?


Recommended Posts

The Kerbal Space Program twitter account just tweeted this:

During Squadcast @maxmaps asked the viewers if we should change the way reaction wheels work in #KSP - what's your opinion?

Use this thread to discuss if and what changes you'd like to see to reaction wheels.

Link to comment
Share on other sites

Not so overpowered to keep a lander straight on an almost vertical slope as long as you have electric charge. As I have purposed in another thread a long time ago, an "overheating like" mechanism would be fine: if the reaction wheel module is pushed at max torque for too long, a bar starts filing and once filled the module stop working for a while. After that, it will work again.

Edited by PlonioFludrasco
stupid smartphone
Link to comment
Share on other sites

I think they should probably work much like they do now for the most part, but I wouldn't be averse to an opt-in mode in the difficulty settings where reaction wheels act completely realistically -- i.e., you'd have to burn some fuel or RCS to stabilise them after a certain amount of use.

Link to comment
Share on other sites

It is a very difficult question.

A: Should they be weaker/stronger? My opinion maybe a little weaker, they are usable for large craft stabilisation where they should be for fuel saving smaller movements. Maybe 90-50% what they are now.

B: Should they build up a non-direction speed? Like PlonioFludrasco said they could build up speed or heat so that they can only run for a certain time. The down side to this is that it is not true to how the real things work (see question C) but it is easier to implement, faster to run and easier for new player to understand.

C: Should they build up direction speed speed? I reality reaction wheels have three (or three with a forth backup) wheels in different axis. The wheels build up speed as they exert a force. If they need to exert a 2 newton force clockwise to rotate a craft then 2 anti clockwise to stop the rotation this is fine and they are at rest in the end. However if as PlonioFludrasco they are trying to constantly right a craft on a slope then they will build up rotation until they fly apart. A craft making left AND right adjustments may not build up rotation but would stop working under option B but wouldn't in the real world. The 3 direction option would require tracking 3 variables and might be complex for new players

Conclusion: In my opinion maybe reaction wheel should track 3 directions. if right clicked on the wheels would show Clock or anti Clock and a percentage of top speed for the three directions. To make it easier for the new players each reaction wheel could have a bar like engine heat (starting at 50% of max?) that would only show the highest wheels speed and only if above 50 or 75%. If it was fine they don't need to know and if it is high they might see the moving red warning bar :P Most people don't have more than 4 reaction wheels so this shouldn't be too taxing on the CPU either.

Oh and add a magnetic rotator (can't find real world link but I know they exist) that very slowly bleeds off speed but using planetary magnetic fields to turn a craft.

Edited by Clockwork_werewolf
Link to comment
Share on other sites

I sort of like them the way they are now, torque-wise. I know they're unrealistically powerful, but nerfing them would just mean spending more mass and part count for the same control authority via more wheels.

Saturation is another issue. It is unrealistic and jarring to have a lander propped up on one or two legs, with the wheels keeping it steady indefinitely. At the same time, I don't really want to micromanage angular momentum accumulation either. Forum member alecdacyczyn came up with an excellent middle-of-the-road suggestion, which was to give wheels a saturation point, but have it automagically bleed away angular momentum at a slow rate when not in use. Not 100% realistic, but limits the biggest exploits while not overcomplicating the game. I really, really like this idea and think it would be a great implementation.

Link to comment
Share on other sites

They should be nerfed in some way so that we will use fins to turn rockets and rcs for large ships in space an equal part of the time as we do the wheels. as of now, if we need to turn any sized ship in any amount of time, you just use reaction wheels... Wouldn't mind seeing a bit of build-up on the wheels, but not to the point where the wheels become a useless part nobody uses because you can't do anything with them...

Link to comment
Share on other sites

I think they should be nerfed, at the moment they are the best solution almost always.

Very large ships may use the liquid fuel RCS engines but normal monopropellant is only for docking.

I think their power doesn't need to be nerfed but some kind of saturation system would be good.

(For that to really do anything the timewarp rotation would have to be fixed.)

Link to comment
Share on other sites

Yeah, as said before, I think that a saturation system is in order, as well as a nerf. A nerf is needed because I can hold landers at a 45 degree angle, which is very strange, even to the newbies playing this game. There should also be a saturation system in place for 2 reasons:

1) Their fuel (electricity) is easily replenishable. This means that you can use reaction wheels for a long time, wait a bit, and then use them for a long time again.

2) They get rid of the need for RCS. If all of your orientation controls are through reaction wheels, there is no need to have RCS, except for docking. Heck, with good engine control you can DOCK without RCS, which effectively gets rid of one important aspect of the game.

The saturation system doesn't need to be complex; it can be a simple timer that slowly ticks down until you regain power. The reaction wheels NEED to be nerfed though, for the sake of balance.

Link to comment
Share on other sites

Not so overpowered to keep a lander straight on an almost vertical slope as long as you have electric charge. As I have purposed in another thread a long time ago, an "overheating like" mechanism would be fine: if the reaction wheel module is pushed at max torque for too long, a bar starts filing and once filled the module stop working for a while. After that, it will work again.

A simplified saturation thing? Sounds alright.

I like that reaction wheels are strong, that makes a lot of things possible. But I like less the fact that they don't behave like reaction wheels- torque just happens. Really, it should apply rotation force around the reaction wheel.

Link to comment
Share on other sites

Actually, that sounds alright, letting them lose saturation and cool off over time wouldn't leave you spinning or cheesing timewarp to stop your rotation.

You still need RCS or an engine to translate, and rather than weaker wheels they should be tweakable.

Oh and some of the probes don't even have reaction wheels, I think that's just fine ;)

Link to comment
Share on other sites

Every probe body should be able to move a normal-sized probe, so that'd mean upgrading the QBE, OKTO2 and Stayputnik. Command pods should be able to move a moderately sized lander/orbiter. Most can do that very easy, so there might be a bit nerfing needed on that front. The 1.25m and 2.5m remote guidance units are used for larger vehicles than probes, so they need a buff to their torques, so that they come closer to the command pods. The guidance units are often used to create spacecraft that are unmanned but the size of manned spacecraft, so their torques need to reflect that. The separate SAS wheels should only be needed in 'normal vehicles' if you have a large launch vehicle to control. A Saturn V-like launcher would need one 2.5m SAS wheel if you wanted to make it easier to turn, etc.

One big thing that needs to change with all reaction wheels however is that there needs to be a direct connection between torque and electricity consumption. The ratios are all over the place. It would make a lot more sense if something with 3 torque has three times the electrical draw of something with 1 torque, etc.

Link to comment
Share on other sites

I feel in the same way about reaction wheel saturation as about limits to engine ignition. It's realistic, but it also requires a playstyle, where you plan all maneuvers in advance, and execute them carefully. I've enjoyed the casual KSP playstyle, where you fly manually, overshoot frequently, and then compensate, and reaction wheel saturation would change that.

On the other hand, reaction wheels are currently so powerful that there are no meaningful choices involving them. Nerf them to around 10 kNm/tonne (which is still around 5x higher than the CMGs on ISS), and you'll have to make real choices between using reaction wheels, RCS, and thrust vectoring.

Edited by Jouni
Link to comment
Share on other sites

I'm okay with RW not suffering saturation issues, however I don't like how ridiculously powerful they're, you can right up a fallen ship with RW alone.

They totally outclass RCS in attitude control to the point that if you aren't going to dock then you don't need RCS. RCS are more tricky to place, need fuel and yet you get a lot less torque out of them than with reaction wheels.

Link to comment
Share on other sites

I think having them saturate after a while, and then either having to torque back the other way or hit a 'desaturate' button would be kinda fun. Especially if more reaction wheel parts mean more total angular momentum and desaturation returned all the stored angular momentum at once.

You could make a catapult.

On a more serious note, RWs should be changed if you want people to use RCS for turning in space. At the moment, pod torque is sufficient to turn most reasonably sized ships and RCS is used mainly for translation (someone else already touched on this). RCS may have to be buffed some for that to work out, though. But that is a little off-topic.

I think they work fine for moving ships around, although that means they're strong enough to be a tad silly sometimes, and they're the only viable way to rotate a spaceship.

Link to comment
Share on other sites

Not so overpowered to keep a lander straight on an almost vertical slope as long as you have electric charge. As I have purposed in another thread a long time ago, an "overheating like" mechanism would be fine: if the reaction wheel module is pushed at max torque for too long, a bar starts filing and once filled the module stop working for a while. After that, it will work again.

I like that. It's a good middle ground between stopping the 'exploits' (keeping landed crafts upright), and not having to worry about tedious problems that comes with saturation under normal use.

If they'd saturate during normal use, every single time you timewarp before completely halting your rotation (which is tedious, and there is no reason you should force people to do that), you'd add saturation that you wouldn't actually get under 'real life' use. So coding in regular saturation would only implent a new problem, which would force them to come up with some way to remember rotational speed during timewarp, which only adds to the lag and doesn't actually add anything meaningfull.

Not to mention the Kraken itself, and phantom forces that would need to be fixed before you could even concider saturation in space

Link to comment
Share on other sites

How about this:

Reaction wheels get saturation in 3 different axis.

Pushing back and forth on the same axis cancels the saturation out.

You can dump saturation with a button, utilizing RCS to spin down the wheels.

When in-flight using thrust vectored engines, SAS could automatically use the thrust vectoring the spin down the wheels as well whenever little torque is required.

Preserving angular momentum in timewarp will need to be implemented.

For balancing reasons, the reaction wheels could now use much less electric charge to operate, and the saturation capacity should be quite big.

For simplicity, saturation is done for the vessel as a whole, no need to do it for each separate wheel. Upon docking reaction wheels would balance out against one another.

Link to comment
Share on other sites

This thread is quite old. Please consider starting a new thread rather than reviving this one.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...