Decoupled boosters don't move outwards and makes my center rocket collapse with them

[galaxy366]

Hey KSP,

I have a really annoying issue with my rocket and have had this more then ones.

So my rocket looks like this: http://i.imgur.com/7jvhH9e.png and everytime the outside rockets burn out and decouple they don't move outwards like this: http://i.imgur.com/TvKeHbT.jpg instead they just hang there and my center rocket mostly slams into them. I tried all 3 but it still happens. Can someone assist me with this ?

Edited April 29, 2014 by galaxy366
Answered :)

[Gordon861]

There are some small solid boosters that can be set to go off with the decouple to power the old tanks away.

Seperatrons

[galaxy366]

There are some small solid boosters that can be set to go off with the decouple to power the old tanks away.

Seperatrons

Can you tell or show which ones they are? I have KSP running currently so I can test it out !

Edit: Pardon me! I found them. Those are pretty tiny.

[galaxy366]

It worked! Thank you

[Stargate525]

That's the solution to your problem. The CAUSE is those struts. Strutting across a decoupler negates the push of the decoupler when it fires.

[FREEFALL1984]

Can you tell or show which ones they are? I have KSP running currently so I can test it out !

Edit: Pardon me! I found them. Those are pretty tiny.

indeed they are tiny but they pack just enough punch to push things clear when decoupling

[Baythan]

After 0.23.5, you could probably get away with only 1 strut per side tank, near the top, just to stop what little bounce happens.

[FREEFALL1984]

also worth mentioning that depending on your booster layout you can sometimes get away with a single sepratron at the top of each booster.

[matt_m]

Its a bug in KSP. When there are parts strutted together "across" a decoupler, the decoupler's ejection force is not applied to the decoupled part.

While not always as effective as using seperatrons, you can install Kerbal Joint Reinforcement (v1.2). If I remember correctly, ferram4 was able to work around the zero decoupler ejection force by disconnecting all the struts between the coupled parts, then firing the decoupler.

[RW-1]

Anyone else getting weird results with struts in the latest version? I had 6 across a large round decoupler to brace a staging section, which I've done many times before without issue, but lately the stages separate, and the lower stage drifts away and the struts elongate, never detaching from the upper section, until I hit staging again.

this morning's separation didnt have that, but the lower stage separated into oblivion, it disappeared ...

[Claw]

Anyone else getting weird results with struts in the latest version? I had 6 across a large round decoupler to brace a staging section, which I've done many times before without issue, but lately the stages separate, and the lower stage drifts away and the struts elongate, never detaching from the upper section, until I hit staging again.

this morning's separation didnt have that, but the lower stage separated into oblivion, it disappeared ...

If you are using the new decoupler, it's possible you're running into the physics bug (especially if there are struts involved). If so, here's how you can fix.

New Decoupler (TR-38-D) causes crash when staging (linux/mac) or parts of the ship to follow around (windows) – [FIX]

When staging, the new decoupler (TR-38-D) causes a variety of problems depending on your operating system. This problem seems to be worse if struts are involved. Thanks to Kasuha, the problem was narrowed down to the physics of the decoupler and is easily fixed.

1) With a text editor (such as notepad) open up the part.cfg file for the TR-38-D. It should be located in KSP\GameData\NASAmission\Parts\Size3Decoupler\part .cfg

2) Find the line that says “PhysicsSignificance = 1†and change it to “PhysicsSignificance = 0â€Â

3) Save the file and restart KSP.

[Project Pluto]

1) With a text editor (such as notepad) open up the part.cfg file for the TR-38-D. It should be located in KSP\GameData\NASAmission\Parts\Size3Decoupler\part .cfg

2) Find the line that says “PhysicsSignificance = 1†and change it to “PhysicsSignificance = 0â€Â

3) Save the file and restart KSP.

THANK YOU!!! I'm using OSX and and that decoupler would sometimes cause KSP to crash. I had no idea why…

[Claw]

THANK YOU!!! I'm using OSX and and that decoupler would sometimes cause KSP to crash. I had no idea why…

You are very welcome. I'm glad it worked.

[Jouni]

Its a bug in KSP. When there are parts strutted together "across" a decoupler, the decoupler's ejection force is not applied to the decoupled part.

I would call it a feature instead of a bug. Staging is much more reliable, when the boosters just fall off. When the decoupler applies any noticeable force, it tends to push the bottom of the booster away from the rocket, making the top of the booster hit the rocket.

[matt_m]

I would call it a feature instead of a bug. Staging is much more reliable, when the boosters just fall off. When the decoupler applies any noticeable force, it tends to push the bottom of the booster away from the rocket, making the top of the booster hit the rocket.

In that case, you need to center the decoupler along the length of the stack betterâ€â€optimally, directly through the center of mass.

[Jouni]

In that case, you need to center the decoupler along the length of the stack betterâ€â€optimally, directly through the center of mass.

Sometimes that's possible, if the center of mass happens to be in the middle of a part in the booster. Still, it's a worse solution than just using a properly designed decoupler that doesn't push the booster away.

[NecroBones]

also worth mentioning that depending on your booster layout you can sometimes get away with a single sepratron at the top of each booster.

Or if you place a pair of them, slightly above the (empty) center of mass for the booster, it will gently rotate out. I usually do this with 2 to 4 pairs. I also sometimes rotate them to 45 degrees, so they push out and down.

There's a caveat though-- if you use multiple sepratrons on the sides of the booster, you might want to place them so the thrust is angled out a little, since the hot exhaust can actually destroy the fuel tank in your center stage (or whichever stage it hits).

[draeath]

Random way to solve the original issue, without using different parts... before decoupling, give yourself some spin. Centripetal force will be your friend, sending that troublesome jetsam away from you with a velocity relative to the angular velocity you have when you mash the button.

If you can't visualize it - stand up and hold something in each hand. Spin around (don't fall!) and let go of the items - just let go, don't toss them. Once you can see straight again, look where they went.