Mechjeb With FAR

[Slywyn]

I've got the latest dev build of MechJeb installed(So features actually work), and I have FAR(Farram Aerospace) installed, and I also have the MechJeb with FAR patch installed, but I'm still having a lot of trouble with using MechJeb features. Now, I know I could just not use them, but frankly most of the fun in the game is just building the ships for me, and I'm really awful at the flying so normally I let MechJeb handle that for me. Right now I can't do that. They oscillate like crazy while flying, they tip over as they're leaving the atmosphere, and it seems to have forgotten how to do a circularization burn properly.

Do these mods just not play well together, even with the patch? Is there a setting I should change? Should I just not use FAR if I want to rely on MechJeb for ascent?

Any answers or information at all would be really helpful, thank you.

[Cairol]

MechJeb with FAR definitely needs other settings than without FAR.
For me it works when I limit the AoA in MechJebs Ascent Guidance to 3° or even less in extreme cases.
Also, enable corrective steering and limit speed to termial velocity.
Let MechJeb not turn the rocket below 4 km. (edit ascent path).
Make sure your rocket is inherently stable by looking at the center of mass and center of lift. CoL should be as far away as possible from the CoM and CoM should be in front of it.
Especially when the first stages tanks are empty, there should still be some margin between the CoL and CoM to reduce the tendency to flip. But I guess you already know that.
Also use struts to make your rocket stiffer.
MechJeb has a hard time getting your rocket to space if it bends like a sausage during ascent.
Limit your engines power if necessary to get a TWR of 1.5 to 2.5 for the ascent stage(s).
Personally, I try to achieve a starting TWR of 2.2 or so for the lower ascent stages (SRB boosters and primary LFO ascent stage).
And I usually do the initial angle correction of just 5 degree or so myself at 3-4 km and activate MechJeb not until I reach 10 km.
This will cause a not 100% optimal gravity turn, but for me it helps to prevent MechJeb to turn the rocket too early
and thus causing stability issues because of the still low speed at 3-4 km.
(As the ascent path set in the ascent path editor never seemed to be respected by MechJeb for some reason. At least that's what I expierience.)

You have to tweak those settings I gave here for your own ascent technique.
But for me it works OK like so.
But nonetheless, MechJeb makes my rocket oscillate much more than a manual ascent with active SAS does.
MechJebs stability controller is better than the stock SAS but also more aggressive with default settings. (and I would not recommend to mess with them...)
For me, limiting the AoA helps with keeping this under control.

Edited December 12, 2015 by Cairol