Not Really Happy with my RCS actions

[Boris Kerball]

Hi Guys

 When Not playing KSP I watch all KSP vids for further lessons I think I have come along way in 4 weeks after watching The Carrera tutorials, Marcus House & Scott Manley, I have built my own version of Apollo 11 split in kerbal orbit re docked decoupled from main engines flew to Muns orbit de coupled landed de-coupled re docked with mother ship (leaving the landing legs on the surface), and got home. BUT after watching some of you guys My RCS is not as clear as yours . I mean I have to rotate to move left then rotate to move up, the only clear  movements I can do with out looking is the forward or backwards movements I use 4 way semi try but it seems all of them work at the same time and they are working slightly when I am not touching and controls, I have leant to dock this way But it would be great if I had =Up down left/right just 4 simple movements. lol any advice or share your best way of design.

Ps could it be my high hat on my joy stick, I mapped this because I could not get on with looking down for buttons and docking at the same time..

 

regards Brian

[Stargate525]

Because of how the standard camera sits, your ship's 'up' and your VISUAL 'up' is very seldom the same thing. That's probably the issue that you're having. As far as them always firing slightly, do you have SAS on? If so, it will utilize the RCS system for stabilization. The result of this is typically a very slow bleed of your RCS as the system uses it to correct pitch/yaw/roll.

[Boris Kerball]

Yes that just what its doing, I click on the docking mode ( Bottom left screen under the rocket icon  is that what you mean sas along with the lighted segment 10.oclock on compass ball??

Gotta leave work now pick up when home...thx.

[Stargate525]

Yes. If you have SAS and RCS lit up on the navball, you'll bleed monopropellant to the SAS stability systems.

[Snark]

6 minutes ago, Stargate525 said:

As far as them always firing slightly, do you have SAS on? If so, it will utilize the RCS system for stabilization. The result of this is typically a very slow bleed of your RCS as the system uses it to correct pitch/yaw/roll.

 

Just now, Stargate525 said:

If you have SAS and RCS lit up on the navball, you'll bleed monopropellant to the SAS stability systems.

 

Unless you turn off the yaw/pitch/roll actuators for the RCS thrusters (that's what I always do in the VAB before launch); that way, RCS won't try to rotate you at all, there won't be any SAS "bleed", and the only thing that will try to rotate your ship is your reaction wheels.

Incidentally, another useful way to conserve monopropellant, when you're using your RCS for lateral thrust, is to turn on "fine control" mode (that's caps lock on the PC, I have no idea what it is on console), which turns on proportional thrust for your RCS and causes them to automatically compensate for placement around your ship's CoM, so that you get smooth lateral translation without induced rotation if your RCS placement happens to not be perfectly symmetrical around CoM.

[Stargate525]

Just now, Snark said:

Unless you turn off the yaw/pitch/roll actuators for the RCS thrusters (that's what I always do in the VAB before launch); that way, RCS won't try to rotate you at all, there won't be any SAS "bleed", and the only thing that will try to rotate your ship is your reaction wheels.

Incidentally, another useful way to conserve monopropellant, when you're using your RCS for lateral thrust, is to turn on "fine control" mode (that's caps lock on the PC, I have no idea what it is on console), which turns on proportional thrust for your RCS and causes them to automatically compensate for placement around your ship's CoM, so that you get smooth lateral translation without induced rotation if your RCS placement happens to not be perfectly symmetrical around CoM.

Oh, I know there's ways to prevent it, just explaining what's currently happening to him.

[Snark]

Just now, Stargate525 said:

Oh, I know there's ways to prevent it, just explaining what's currently happening to him.

Yes, and I'm explaining to him how to stop what's happening to him from continuing to happen. 

[Dman979]

13 minutes ago, Snark said:

Incidentally, another useful way to conserve monopropellant, when you're using your RCS for lateral thrust, is to turn on "fine control" mode (that's caps lock on the PC, I have no idea what it is on console), which turns on proportional thrust for your RCS and causes them to automatically compensate for placement around your ship's CoM, so that you get smooth lateral translation without induced rotation if your RCS placement happens to not be perfectly symmetrical around CoM.

Are you sure that's what fine controls do? I was under the impression that it started firing your RCS at 10% of full thrust, and slowly ramps the thrust up.

[Snark]

18 minutes ago, Dman979 said:

Are you sure that's what fine controls do?

Yup. 

To be clear, "fine control" mode also reduces the overall amount of control that happens, as you say.  But it also has this neato nifty magical keen "auto balance RCS thrust to compensate for placement around CoM placement" feature, which has been around since forever and is, alas, one of the best-kept secrets of KSP.  It's so cool-- and so under-appreciated-- that I trumpet about it every chance I get.

Moral of the story:  always turn on fine control mode whenever you're docking, and things just magically get better.

[Dman979]

2 minutes ago, Snark said:

Yup. 

Does it do the 10% thing, too? Or am I just completely wrong?

[Snark]

Just now, Dman979 said:

Does it do the 10% thing, too? Or am I just completely wrong?

I have no clue what the actual percentage is, but yes, it does overall reduce the strength of RCS thrust and reaction-wheel torque, as you say, yes.

However, as far as I'm concerned, that behavior's irrelevant.  After all, when docking, one should only be doing brief taps on the RCS thrusters anyway, and in my experience, the strength reduction effect of fine control mode is virtually useless-- it's easy to get very small adjustments with brief taps, even at full power.  That's why, in the past, I never, ever used fine control mode at all... until I found out about the magical compensate-for-CoM-placement feature, which suddenly (for me, anyway) changed fine-control mode from "completely useless" to "absolutely mandatory" when docking.

 

[Dman979]

3 minutes ago, Snark said:

That's why, in the past, I never, ever used fine control mode at all... until I found out about the magical compensate-for-CoM-placement feature, which suddenly (for me, anyway) changed fine-control mode from "completely useless" to "absolutely mandatory" when docking.

 

Huh.

Hard mode- dock a small probe using full-thrust Twinboars.

[Kevin Kyle]

14 minutes ago, Snark said:

Yup. 

To be clear, "fine control" mode also reduces the overall amount of control that happens, as you say.  But it also has this neato nifty magical keen "auto balance RCS thrust to compensate for placement around CoM placement" feature, which has been around since forever and is, alas, one of the best-kept secrets of KSP.  It's so cool-- and so under-appreciated-- that I trumpet about it every chance I get.

Moral of the story:  always turn on fine control mode whenever you're docking, and things just magically get better.

I did not know that, TY for bringing this to my attention. I will certainly be using this feature a lot more now that I know this. Learn something everyday.

[Snark]

15 minutes ago, Dman979 said:

Hard mode- dock a small probe using full-thrust Twinboars.

If one were inclined to quibble, one might raise an eyebrow at the description of any craft with Twinboars as "small"...

[DerekL1963]

1 hour ago, Snark said:

If one were inclined to quibble, one might raise an eyebrow at the description of any craft with Twinboars as "small"...

Or the misspelling of "totally batstuff insane" as "hard".

[beelzerob]

2 hours ago, Snark said:

 

 

Unless you turn off the yaw/pitch/roll actuators for the RCS thrusters (that's what I always do in the VAB before launch); that way, RCS won't try to rotate you at all, there won't be any SAS "bleed", and the only thing that will try to rotate your ship is your reaction wheels

That's brilliant.  I always would turn RCS off to change orientation while docking then turn it back on for movement and that was a major pain, since both kinds of movement are regularly needed.  I never thought to deactivate them in that role altogether.

[moogoob]

Were it up to me, RCS rotation control would be OFF by default on all RCS parts but the Vernors.

[Snark]

2 hours ago, beelzerob said:

I always would turn RCS off to change orientation while docking then turn it back on for movement and that was a major pain

Yes, that's what I always did, too, and it was, indeed, a major pain.  That's why I was so overjoyed when they introduced the actuator toggles to RCS in 1.1.x. 

[Kerbart]

4 hours ago, Snark said:

Incidentally, another useful way to conserve monopropellant, when you're using your RCS for lateral thrust, is to turn on "fine control" mode (that's caps lock on the PC, I have no idea what it is on console), which turns on proportional thrust for your RCS and causes them to automatically compensate for placement around your ship's CoM, so that you get smooth lateral translation without induced rotation if your RCS placement happens to not be perfectly symmetrical around CoM.

FINE CONTROL CAN BE ANNOYING WHEN YOU VISIT THE FORUM IN BETWEEN MANEUVERS THOUGH.

I didn't know about the thrust balancing though. That's pretty cool.

[Allocthonous]

5 hours ago, Snark said:

To be clear, "fine control" mode also reduces the overall amount of control that happens, as you say.  But it also has this neato nifty magical keen "auto balance RCS thrust to compensate for placement around CoM placement" feature, which has been around since forever and is, alas, one of the best-kept secrets of KSP.  It's so cool-- and so under-appreciated-- that I trumpet about it every chance I get.

I am very glad that you trumpet about this. I had no idea. Between this, the actuation controls, and having translation mapped to IJKL so it can be used while in rotation docking mode, I feel like I can dock just about anything.

[moogoob]

16 hours ago, Allocthonous said:

I am very glad that you trumpet about this. I had no idea. Between this, the actuation controls, and having translation mapped to IJKL so it can be used while in rotation docking mode, I feel like I can dock just about anything.

If you use an xbox controller you can map rotation to the stick and translation to the d-pad. Fore/aft and roll are on the LR triggers and bumpers. That's what I use - very easy with the analog control.

[eddiew]

Ignore the pretty pictures of spaceships and pay attention to only the nav ball, speed, and range to target indicators.

Sounds silly, but it works - the full flight scene gives you too much visual information and there's a discrepancy between the vessel's "up" and your "up". Navball's up is also your up, and that's what you need to act on. Hold the target in the centre, hold the velocity vector in the centre, keep closing speed reasonable and sooner or later you dock  

[Archgeek]

On 10/18/2016 at 11:10 AM, Dman979 said:

Huh.

Hard mode- dock a small probe using full-thrust Twinboars.

On 10/18/2016 at 11:26 AM, Snark said:

If one were inclined to quibble, one might raise an eyebrow at the description of any craft with Twinboars as "small"...

On 10/18/2016 at 0:56 PM, DerekL1963 said:

Or the misspelling of "totally batstuff insane" as "hard".

Will you dorks stop making me laugh?  I'm gonna hit my daily rep limit at this rate.

Just be glad we're not on Nightmare -- I hear that involves using staged, full-thrust Flea SRBs for reaction control, a la @Whackjob.

[marcushouse]

On 19/10/2016 at 2:02 AM, capt: scarlet said:

 When Not playing KSP I watch all KSP vids for further lessons I think I have come along way in 4 weeks after watching The Carrera tutorials, Marcus House & Scott Manley...

Just thought I'd say Thanks for Watching!  Good luck with your RCS woes. Locked camera mode is your friend here (lets you easily interpret directions. SAS mode can cause all sorts of strange issues with RCS. A lot of the time I turn SAS off, and then use WASD and IJKL with HN all at the same time using small adjustments. Takes practice, but it will become easy over time.

I did one tutorial here that may help

 

Edited October 20, 2016 by marcushouse

[tg626]

Have you guys tried pressing V until your in Locked camera mode?  Standardizes which direction your translation controls move you. (IJKL)