having trouble controlling ascent

[jake264]

I can't seem to control my vehicle very well.

Basic vehicle:

OKTO2 with MK16 chute on top, FL-T400 tank and LV-T30

Centers of mass, thrust, and lift all look good (as far as I know)

control input test on pad works, yaw, roll, and pitch indicators show full range of movement.

My tests with solid rockets worked fine, no problems at all.

Full thrust takeoff, at about 1800 meters, this thing start to tip right sharply, and no amount of opposite yaw input has any effect whatsoever on correcting it.

At 1/3 throttle, I can control the craft until the fuel runs out, but any higher throttle than that and it quickly goes out of control.

Is it so squirrely just because there is so much thrust for a light vehicle? As I understand it, it's more efficient to be full throttle for a while after takeoff, but perhaps that's not the case here?

[leptoon]

Two words: structural wings. Also, I know you mentioned this, but make sure your center of mass is near the middle of your craft. I had problems with unstable flight when my center of mass was too low.

Edited June 24, 2013 by leptoon

[Eric S]

I can't think of any reason for that craft to be out of balance.

My only suggestion is to swap the LV-T30 out for an LV-T45. The probes have almost no reaction wheel command authority, the LV-T30 doesn't have vectored thrust, and you have no other control on that craft.

[CCKinnison]

Agreed with both these suggestions. I suspect the problem is with balance shifting as you burn fuel.

[robocop]

Try adding an SAS to improve stability