Can't lauch straight up with Landing Struts?

[SpitfireJoe]

Hi!

I still pretty much a KSP beginner, I played a bit before the official release. Now I'm playing on Science Mode and I want to land a Kerbal on the Mun, but I have a problem. I've built a rocket that can easily reach Orbit and even the Mun. But as soon as I add landing struts to the "landing part" I can't seem to launch the rocket from the launchpad straight up. Without the struts reaching orbit is easy, with them I just can't manage because the rocket starts tipping straight away... Is it normal that the landing struts have such a large impact? And what can I do to fix the problem? Maybe I am attaching them wrong, but I tried to balance them out and everything. 

Below some screenshots of my rocket with and without landing struts.

Thanks for your help!!

Without landing struts:

 

With 3 landing struts:

 

With 6 landing struts, symmetrical to the tanks below:

[ibanix]

The landing legs ('struts' is used by most players to mean the struts that hold ships together) may be causing excess drag. Try adding additional wings, reaction wheels, or RCS (in that order) to better control your heading. 

[Snark]

I see that you already have some fins on your center stack, so it's good that you're making some effort at aero stability.  But the likely culprit here is that it's simply not stable enough.  Rather:  without the landing legs on, it's OK but marginal.  Adding the high-drag landing legs up near the front of your stack may be enough to push it over the edge into instability.  The fact that you have non-gimbaled engines and therefore have very little control authority makes the problem even worse.

A few suggestions, in no particular order:

• Replace at least some of those Reliants with Swivels instead.  The Swivel has the ability to gimbal, which will help maintain your stability when SAS is turned on.  If you choose to use a mix of Reliants & Swivels instead of going 100% Swivels, then the Reliants should be the first engines that you stage away, since the Swivel has superior Isp at low atmospheric pressure.  At the very least, the engine on your center core should absolutely be a Swivel rather than a Reliant.
• Move the asparagus tanks down.  Way down, as far as you can go.  As they empty out, your CoM will move upwards, which will help your stability.
• Add more (or bigger) fins.
• Make sure that your landing legs are retracted during launch; they have less drag that way.  (I bring it up because they look extended in one of your screenshots.)
• Looks like you have a stack of 2-ton tanks in the middle.  Be advised that using a stack of tanks tends to cause stability problems, because the stack drains from the top down, which moves your CoM radically downwards and kills your stability.  Suggest using a single 4-ton tank instead, with a 2-ton tank on top of it which is disabled initially so it won't drain.  You can then enable that top tank when the 4-tonner beneath it is mostly empty.

[Vanamonde]

Are the landing legs pressing on the booster stacks, causing them to tilt and apply thrust at odd angles? 

[bewing]

Hmmmm. I don't use landing legs in 1.1.2 at all, because of the issues (I tend to use wing parts for landing legs instead). However, I think I see that you have some actual struts in there, too. And I can tell you for a fact that struts sometimes have a bug that makes them have large off-center masses which will cause your ship to veer. It may be that the landing legs have that same off-center mass issue that struts do. I don't think this is an issue with your rocket design -- although snark's suggestions are good ones in general. But all I can suggest is to trash the legs and land on something else until the leg issues are resolved.

[SpitfireJoe]

Thank you for all the suggestions! I'll try all of this out and get back to you if it worked

[SpitfireJoe]

Okay, a combination of more wings, a reaction wheel and using swivel engines worked! Thank you all so much
Now I can try and land Jebediah on the Mun