Need help with a spinning rocket

[Duckle]

Okay, i'm relatively new to KSP and this is my first mission to Duna so it might be massively overkill. i'm trying to send a rover to duna on this mission.

The rover i'm trying to get off the ground is ever so slightly imbalanced and the rovercore is upside down. just after i launch the rocket, it enters a roll i can't counteract with ''E'' or ''Q''.

I've tried a dummy payload of the same weight as the rover. the payload consisted of just some fuel tanks to see if the imbalance is the problem. in this same launch i set a probe core in the proper position so it isn't upside down anymore. however, it turned out none of this is the problem because the same spinning happened. also, i believe there is a part clipping bug that might cause this spinning but i also eliminated that problem with the earlier mentioned test run. (although i don't think there are any bugged parts on the rover)

Here are some pictures of the craft: https://imgur.com/a/iJDYHcf

The gimbal is disabled on the booster vector engines, so only the core has gimbal.

i really don't know anymore so i would like to ask you for help or potential solutions.

 

[ARS]

Add some reaction wheel. Turn in stability assist to stabilize the rocket. If using dummy payload didn't work, use structural beam as a frame and attach 2 rovers side by side by using symmetry mode. That way, 2 rovers on each side balances the rocket. The 2 side by side rocket/ payload is useful for asymmetrical payload

Or, if the rover core is YOUR MAIN CORE, then that's the problem. My usual setup is, the rover core is the secondary core, while rocket core is the main core. Build the rocket first, with drone core as the first part, then attach the rover with the drone core as the payload. That way, your control reference is from the rocket, not the rover. As long as the rover has a drone core, it'll be controllable once it's separated from the rocket

Edited July 18, 2018 by ARS

[bewing]

Instead of reaction wheel, I'd add two pairs of steerable fins at the bottom of your boosters (45 degrees off the line of symmetry). They will add stability, and for the first minute or two of your launch they will give you a lot more steering control than you have now.

 

[The Flying Kerbal]

I'm at work right now and the boss has this thing about me working for him and not the KSA, not a very helpful attitude that...

Not being able to see your photos on a proper monitor, I really can't tell  if there's anything wrong with your rocket, but it looks OK on my phone.

One thing that did leap out at me was all that brown on the navball; it should be blue as you're pointing straight up at the sky when sitting on the launch pad.  However although that's not good, I don't think it would create a roll as you describe, it sound more like you have torque being generated by your payload being slightly off centre.

If you have Kerbal Engineer Redux installed, bring it up while you're in the VAB and look at the torque value.  If it's not 0.00, try using the offset tool to move it around slightly to see if you can bring that value down.  If you haven't KER then just make small adjustments to the position of the rover and test launch.  It'll be trial and error but it should work if that's the problem.

Also, a lot easier, remove and replace the fins at the bottom of your rocket, just in case they have somehow ended up not being on straight.  It wouldn't hurt to even try a launch without them.  It'll probably end in tears doing that, but you can't make an omelette without cracking some eggs!

I must say from what I can see on my phone, it looks like you've made yourself a fine looking rocket mate, I really like it!

[Xd the great]

Unfortunately, your probe core does not have SAS. Use another one. Id suggest a 2.5m sized one.

or use reaction wheels.

Or use shorter rockets.

Or add fins to the bottom of your first stage. 

The key to building a successful rocket is that it looks like a real life rocket

[Kryxal]

Do you have struts from the boosters to the inner stack?  I don't see auto-strut doing the best job for this, but a pair of struts on each side would fix any off-angle thrust there.  Also, I'd add another control point with the correct orientation and use that to fly the rocket.

[StrandedonEarth]

Yeah, you may need (more) struts for the boosters. If they get wobbly they can make the whole stack roll, I've found that out for myself the hard way

[Duckle]

Thanks for all the responses, i have tried most of them and i got it into orbit!

Thanks to kerbal engineer i managed to balance the ship out further and with the help of some reaction wheels it didn't roll that bad anymore. it came to the point where i could control it myself. the problem seemed to sit with the boosters because they had a torque of 0.18 and as soon as i detached them the rolling stopped. 

anyway i thank you all that i can now do my first interplanetary mission.

[ARS]

Good luck! 

[The Flying Kerbal]

Congratulations and Godspeed for your trip to Duna! ☺

[Xd the great]

Rcs, solar panels, batteries and reaction wheels all set up? And also the parachutes too.

I suggest landing on minmus/mun first.