Overly dramatic rocket vibrations

[Nabiscovinco]

Hi!

So I've been launching a series of Duna probes (2) but each time I've launched them, the rockets have been vibrating rather violently. It's to the point of unacceptable. Strangely, it's only the mainsail.

Anyone else struggling with this?

Edited December 9, 2013 by Nabiscovinco

[hypermetric]

During launch or flight?

[700NitroXpress]

I believe your issue is that the mainstall is producing enough power that it wants to separate itself from the rocket or already has. This can happen if you're launching things that a really lightweight with a really powerful engine. The engine wants to detach and go it's own way. It also depends on what you have this mainstall attached to. If you have an orange fuel tank with a 1440 grey fuel tank on the bottom and then attach the mainstall to that, it shouldn't shake. You can also try using struts to strap the tanks to each other to prevent separation. If you have multiple mainstall engines on a craft, you want to strut the tanks that they're attached to together at the bottom and top of the tanks to prevent vibrations or movement.

It would also be helpful to see a picture of your craft that way people can suggest solutions.

[Taki117]

you could also get the Kerbal Joint Reinforcement plugin (on my phone or I would have a link) it will help with wobble.

[SRV Ron]

Bracing is needed to hold things together. Proper bracing can make the difference between this;

Or This;

[Nabiscovinco]

All wonderful suggestions! Thank you! It's probably the fact there is a small satelite attached to the top (my justification is it is going to Duna, but considering I only made the interplanetary jump twice... I'm counting it as inexperience).

[Taki117]

You should try keeping yourspeed right at, or just under, terminal velocity. this will not only cut down on engine wobble (because currently your mainsail is producing way more thrust than needed) but it will also help you save fuel. (Because you reach the point where air resistance and gravity are about the same thus going either faster or slower causes dV loss to one or the other respectively)

[MalfunctionM1Ke]

Here is your solution.

Try to strut the tanks together as you see here on above and below the orange tank. You can also strut the Mainsail onto the Tank above it by placing the strut on the lowest Point of the side of the tank and than on the Engine so that the strut is on the Engine and not on the border where the tank ends.