Seperating RCS from rotation and SAS

[Mlah]

I was messing around when I noticed the tritium RCS thrusters where ridiculously over powered to the point where I could use them in place of engine and only need a single fuel tank that could give me tens of thousands of dv. So I have been having fun building probes and landers using nothing but RCS but the problem I am running into is I will have massive banks of RCS thrusters and if I want to tilt the ship a little while I am doing a burn instead of just using the reaction wheels it will try to use every thruster to turn causing the ship to spin violently. Its even worse with SAS enabled as it creates a tremor that just builds ups as it tries to correct itself, each time overshooting more, ending with the whole ship shaking back and forth. I need RCS for my forward thrust so I am wondering if there is some way either through the stock game or a mod that will make it so that when I rotate it only uses the reaction wheels installed on my craft.

[Taki117]

if you hit 'R' it will turn off your RCS.

[Mlah]

if you hit 'R' it will turn off your RCS.

I realize this but I am not trying to turn RCS off. Like I said I RCS is what is providing my forward thrust so I need them running as I make my maneuver. What I want is to be able to keep my RCS thruster that are pointing down running and then be able to pitch to the side using the reaction wheels without half of my RCS thrusters turning off and flinging me into a wild spin.

[psyper]

I think what Taki117 is trying to say is that while thrusting and you need to adjust your course you may need to turn off rcs, maneuver, turn rcs back on and then keep thrusting. I don't think there is a way to disable individual rcs jets on an rcs part otherwise you could turn off the lateral rcs jets and just leave the ones you're using as rockets.

[Taki117]

I realize this but I am not trying to turn RCS off. Like I said I RCS is what is providing my forward thrust so I need them running as I make my maneuver. What I want is to be able to keep my RCS thruster that are pointing down running and then be able to pitch to the side using the reaction wheels without half of my RCS thrusters turning off and flinging me into a wild spin.

Ah, ok. No way I know of doing this. You might try using Docking mode, but beyond that I don't think it's possible.

[Redshift OTF]

Can we see a pic of your ship? Sounds interesting. I think you can toggle RCS ports with action groups if that will help. Also if that doesn't work maybe hitting capslock for fine control will ease the problem.

Edited April 15, 2014 by Redshift OTF

[Drew Kerman]

are there not single-output RCS ports? I know I've seen some in videos. Maybe mod parts. I dunno never had to use them and I'm in career so if they're there I haven't unlocked them yet

[BudgetHedgehog]

MechJeb recently had the addition to 'Use SAS for rotation' and also 'Use RCS for thrust when fuel runs out' or something, so the RCS acts like your engines (can even have half throttle etc). Sounds exactly like the thing you're asking for.

[m4v]

Stock? no. You would need to write a new module for those RCS with that feature.

[Red Iron Crown]

I started a thread in the Suggestions subforum about exactly this issue. Seems like posters supported it, whether the devs implement it who could say?

I didn't realize MechJeb had implemented something similar, I should poke around in the windows to try it.

[BudgetHedgehog]

Can't remember the RCS for thrust option location, but use SAS for rotation is in the RCS Balancer window I think.

[Red Iron Crown]

Can't remember the RCS for thrust option location, but use SAS for rotation is in the RCS Balancer window I think.

Thanks, I'm more interested in that option than RCS for thrust.

[Pecan]

The 'place anywhere' ones are single-output.

You can right-click and toggle any thruster on/off - affects them using symmetry AFAIK so you'll have to place them individually if that's how you want to control them.

Same thing can be done with action groups. Using the excellent Action Groups Extended mod they are individually controllable, regardless of symmetry.

[Redshift OTF]

I've been using the use RCS for thrust option in MechJeb and it is very useful. It also has the option of turning off RCS for turning so you can keep SAS for just turning and RCS just for thrust. I think I can finally get my Eve plane working at last.

[Superfluous J]

Single output or not, they'll still fire if they're even slightly off center from your COM and you turn.

I'd love to be able to set their control kind of like flaps. Instead of pitch and yaw all we'd need, probably, is "rotate" and "translate" buttons.

[Mlah]

I can't seem to find the RCS for thrust option although mechjeb seems to automatically do so and is much better at keeping the rocket stable. I did find the "use RCS for rotation" and tried unchecking it but that required turning on smart translation first which prevented my thrusters from actually generating enough thrust to lift the vessel Also just messing with the option clicking "use RCS for rotation" would cause all the top facing thruster to emit a massive thrust plume much longer then normal that looked like a massive fireball which was awesome.

Other things I have tried is messing with placement and type. For example my original designs which I am going to put below used the 4 way thrusters so I tried using just the single directional ones. I think that made it a little better but they still get used for rotation causing the same problems.

Last but not least here are some picture of what these craft look like so you can see how I am using these.

Here is one of my first tests, this guy actually worked pretty well and I was able to get him into orbit which is where he currently resides mapping kerbin's kethane deposits. Hes a little low on thrust though.

This is my current design that I am having the most problems with. I wanted to build him with a lot of thrust so he could push asteroids around. I don't have a screen shot of it but I attempted switching to mono directional thrusters and placing them underneath the pillars but it didn't halep much.

[HeadHunter67]

are there not single-output RCS ports? I know I've seen some in videos. Maybe mod parts. I dunno never had to use them and I'm in career so if they're there I haven't unlocked them yet

Yes, there are. The Linear RCS Port can be placed anywhere, and only produces thrust in a single direction. However, unless the only RCS ports on the ship are used for thrust, it probably won't fully solve the OP's issue.

[Redshift OTF]

Thanks for the pics. Although I don't think you can solve the problem I think you can mostly mitigate it enough to still use RCS thrusters for thrust. I use the octagonal struts and attatch multiple single direction RCS thrusters to those and stack them together to make a thrust tail. If most of the ports are in line with the centre of mass then the turning effect will be minimal. On landers the tail could sit at the top of the craft. Not ideal or pretty but it could work.

[Mlah]

I think that's what I am going to end up doing. I wanted to avoid a tower just because I like the way my spider probes look but an inverted hammer could be fun.

[WaveFunctionP]

rls stockalike has true monopropellant engines which may be more what you are looking for.

Personally, I'd like to see those tiny low thrust engines converted to monopropellant engines, since they aren't really that useful. It would be simple enough to do with an MM config if you don't want to use rla.

Edited April 16, 2014 by WaveFunctionP