Well, whats wrong with this rocket????

[Space boy]

https://imgur.com/1guzzzJ

https://imgur.com/gn7RC0Y

i think my payload is a problem...

Can you check it please???

sorry for not replying for a time..

The rocket flips at around 6000m

Edited October 26, 2019 by Space boy

[Pecan]

1 hour ago, Space boy said:

https://imgur.com/1guzzzJ

https://imgur.com/gn7RC0Y

i think my payload is a problem...

Can you check it please???

sorry for not replying for a time..

The rocket flips at around 6000m

This has 1km/s more than it needs.  Pitched 10 degrees at 90m/s after launch, waited for prograde to catch up, then fixed SAS prograde until apoapsis set.  Big fairing, no fins, SRBs doing the steering.

[Xd the great]

8 hours ago, Space boy said:

https://imgur.com/1guzzzJ

https://imgur.com/gn7RC0Y

i think my payload is a problem...

Can you check it please???

sorry for not replying for a time..

The rocket flips at around 6000m

Fairing head isn't pointy enough.

[Jodo42]

When you have big, awkward fairings/payloads like this, you could try taking a much steeper trajectory. Go back to your original design with the SRBs and fly straight up until your apo gets >100k or until you're above 30km in altitude- don't turn even a little bit or your rocket will flip. Once you're above 30k then you can gently turn the rocket. Just remember your circularization burn is going to be longer than it usually is and your lifter might need some extra delta-v/boosters to get it to orbit properly. It looks like you have plenty of funds to throw at the problem, so this might be as simple as "moar boosters"

Edited October 27, 2019 by Jodo42

[Superfluous J]

I was looking for something to to on Twitch and maybe fixing your rocket would be fun. Could you upload the craft file somewhere like KerbalX? It looks stock, so it shouldn't be a problem loading it.

[Space boy]

https://imgur.com/ZZPYdV1

Ok this is another rocket that I am building for a satellite contract with a survey scanner and materials bay and I have covered it up with a fairing..

but guess what??? This rocket flips too!

This time it flips at around 3000m and I tried reducing the TWR and added fins but nothing works it still keeps on flipping no matter what.

And i have also noticed that whenever I place fairings in a rocket, it flips but when I launch rocket which are already aerodynamic like with the command modules, they never flip.

 

[Harry Rhodan]

13 minutes ago, Space boy said:

And i have also noticed that whenever I place fairings in a rocket, it flips but when I launch rocket which are already aerodynamic like with the command modules, they never flip.

Because you always make them comically large. The one on your latest screenshot is at least twice as wide as the rest of your rocket. I mean the obvious lesson here is to not put a payload that is much wider than your launcher on top of your rocket.

[Xd the great]

39 minutes ago, Space boy said:

https://imgur.com/ZZPYdV1

Ok this is another rocket that I am building for a satellite contract with a survey scanner and materials bay and I have covered it up with a fairing..

but guess what??? This rocket flips too!

This time it flips at around 3000m and I tried reducing the TWR and added fins but nothing works it still keeps on flipping no matter what.

And i have also noticed that whenever I place fairings in a rocket, it flips but when I launch rocket which are already aerodynamic like with the command modules, they never flip.

 

This:

22 minutes ago, Harry Rhodan said:

Because you always make them comically large. The one on your latest screenshot is at least twice as wide as the rest of your rocket. I mean the obvious lesson here is to not put a payload that is much wider than your launcher on top of your rocket.

Also, add some rear fins for stability.

Edited October 27, 2019 by Xd the great

[Space boy]

https://imgur.com/m1AgLBo

I changed the fairings like this but the rocket still flips. I have attempted to keep the radius of the fairing as low as possible and if I attempt to reduce the radius any further the game wont let me place the fairings.

Edit: I tried it once more and it launched relatively properly, but it did what I wanted it to do.

Edited October 27, 2019 by Space boy

[Foxster]

You've been told about 4 times that the fix is to fit some fins at the back end (think a dart or an arrow) but you don't seem interested in following that advice so, yes, your craft will continue to flip. 

[Xd the great]

2 hours ago, Space boy said:

https://imgur.com/m1AgLBo

I changed the fairings like this but the rocket still flips. I have attempted to keep the radius of the fairing as low as possible and if I attempt to reduce the radius any further the game wont let me place the fairings.

Edit: I tried it once more and it launched relatively properly, but it did what I wanted it to do.

Use a wider rocket. 1.875m fuel tanks will be better. No need to extend each part of the fairings all the way. A short, just wide enough base, a tall, straight middle, and a pointy head. Consider using Atlas rockets as an example, but I personally prefer Delta IVs.

Edited October 27, 2019 by Xd the great

[Space boy]

57 minutes ago, Foxster said:

You've been told about 4 times that the fix is to fit some fins at the back end (think a dart or an arrow) but you don't seem interested in following that advice so, yes, your craft will continue to flip. 

even if I add fins, the craft flips.

And in real life there are alot of rockets that which fly without fins like the falcon 9 and are completely controlled by engine gimbals so I am more than happy to add fins on my rocket if thats what works in ksp but I would like to know how it is possible IRL. I am sorry if I didnt attach the fins the first time you said because I was getting real confused with what was happening.

[mk1980]

i don't think you have to make the fairing that wide. the solar panels stick out a bit and the scanner antenna is a bit larger than the 1.25m cross section, but the conical shape is impractical. try something like this maybe:

https://imgur.com/a/wgQynBy  

pointy at the top, no sharp edges, mostly cylindrical body. as long as you don't oversteer and keep it pointing prograde you won't even need fins 

 

Edited October 27, 2019 by mk1980

[Space boy]

Just now, mk1980 said:

i don't think you have to make the fairing that wide. the only items. the solar panels stick out a bit and the scanner antenna is a bit larger than the 1.25m cross section, but the conical shape is impractical. try something like this maybe:

https://imgur.com/a/wgQynBy  

pointy at the top, no sharp edges, mostly cylindrical body. as long as you don't oversteer and keep it pointing prograde you won't even need fins 

 

cool, I will try it out.

[Xd the great]

7 minutes ago, Space boy said:

And in real life there are alot of rockets that which fly without fins like the falcon 9 and are completely controlled by engine gimbals so I am more than happy to add fins on my rocket if thats what works in ksp but I would like to know how it is possible IRL. 

They have pointy fairings, and the width of fairings is only slightly wider than that of the rocket fuel tanks.

[Space boy]

https://imgur.com/DODQVTz

So I made this rocket to intercept an asteroid, and it flies perfectly!

Can you please tell me what I did right here? 

And also, it flies completely on engine gimbals.

Edited October 27, 2019 by Space boy

[Harry Rhodan]

2 hours ago, Space boy said:

Can you please tell me what I did right here?

The nuclear engines are comparatively high and heavy so your CoM might be high enough for the pressure on the fairing to have less leverage than the pressure on the bottom of your rocket.

[Xd the great]

7 hours ago, Space boy said:

https://imgur.com/DODQVTz

So I made this rocket to intercept an asteroid, and it flies perfectly!

Can you please tell me what I did right here? 

And also, it flies completely on engine gimbals.

2 side boosters add extra drag near the rear, helping to keep it pointed in the right direction. Also, you might have used a less aggressive gravity turn.

Edited October 27, 2019 by Xd the great

[Linkageless]

Without trying the craft myself, I can only speculate that the upper end of the payload has much more angular drag than any other part when you venture out of the prograde marker.

The leverage of high drag so far up is likely the problem. The F12 display should indicate this drag the moment you start to pitch.

It's likely that spent fuel and/or discarded stages will be raising your CoM, but at the same time loss of any discarded parts may raise your centre of drag.

First, I would try to slim down the width of that top lander to reduce the diameter of the fairing you need. Then, see if you can make the mission work with it below the rest of your payload. Rotate it all 180 degrees may be a quick way.

With your new slimmer and less top draggy fairing, you will need less fuel for the same DV and can get away with much less TWR, so reduce the number of engines and perhaps thrust they are set to. (Solid boosters can still be useful burning slower for longer. )

Less TWR = Less speed in the thicker parts of the atmosphere, so less drag at that critical moment you wish to make a gravity turn.

Another approach may be to get your pitch set before you gain much speed, practice or launch clamps may help you achieve this..