Whats best RCS wise for this ship part?

[scooterjes]

I was wondering if the RCS layout with 4 on each end would be improved by putting 8 on the center of mass. If you are curious those are the arms for my Space Station.

http://steamcommunity.com/sharedfiles/filedetails/?id=164741529

[SRV Ron]

They have the most leverage when mounted on each end of the station. The station should then rotate around its center of gravity with minimal thrust and fuel and translate in a straight line.

For a rocket, they work best for the command module at its center of gravity. Only one set of 4 is needed for center of gravity.

On a long rocket, they can be on the probe or last stage. The rocket will easily pivot at its base. It can also translate forward and reverse but will not translate in the diagonals. You can use a probe stage thrusters to control everything without using it's fuel tank by disabling it so fuel is used from a tank mounted on an upper stage. I have found that the new SAS has sufficient torque that I no longer need to use thrusters for orientation on my interplanetary craft.

Edited July 29, 2013 by SRV Ron

[Wesreidau]

Always place RCS oriented according to your command module. If your command module faces north, put a port north, south, east, and west. Mounting RCS ports at angles results in wasted propellant because some fraction is being diverted in a direction that another force has to counteract. When possible, consider mounting RCS ports on the ends of long beams of the lightweight girders. This puts the force further away from the center of mass, and so you get better leverage (or so I've convinced myself).

[TheLastMonkeylander]

Speaking of RCS layout, can RCS thrusters damage your rocket like regular engines can?

[Wesreidau]

Nope. Cold boring gas. Would probably foul up solar panels IRL, but not here.

[Broco]

You can even save some more RCS-fuel if you place a Place-Anywhere 7 Linear RCS Port directly next to a RV-105 RCS Thruster Block and just use the left and right sides of your craft (sparing top and bottom). I do that with my space splanes all the time, works fine.

[scooterjes]

Thanks for the info I am a crappy pilot but a decent builder so unfortunately I have to rely on MechJeb to most of my piloting. I am so glad the RCS system is much more efficient so I know that I probably put way too much RCS on that but I do intend to make it a both a fuel depot and a space station my station has 3 of those "arms" to give a total of 12 regular Clamp-o-trons and 3 of the big Sr. Clamp-o-trons if I ever need more that that i will need to do a major redesign. Thanks for the info 4 on each end has worked well in the past but was wondering if moving them would make a big difference.

[Nick4]

Dude if you say that you're a crappy pilot then I'm a serial killer of Kerbals.

[Geschosskopf]

Be sure to check out the RCS Build Aid mod, too. With it, you'll always put your thrusters in the best places, especially now that the mod shows your CoM with both full and empty tanks .