SRB separation always blows my ship up

[Wanderfound]

Yeah, I tried the same but with one also pointing vertically, thruting downwards. It may have been due to FAR but from what I can tell it's impossible for me to separate in surface atmospheres

Stock aero is a distant memory, so I can't promise anything, but: try it without the down one. It may be pushing your booster back into the core.

[ferram4]

@TimberWolfe: Try waiting until you're going faster than 750 m/s to decouple. The decoupler changes to try and get them to work in win64 made them not play well with velocities below the Krakensbane limit.

[TMS]

Y'all completely wrong. I know exactly what OP is talking about. Apparently it's a bug in 0.24.2 where SRBs, no matter where mounted our what measures taken, always gravitate inwards.

Kinda. The bug is in the radial decouplers.

Solution

Config file edit: http://forum.kerbalspaceprogram.com/threads/88026-Radial-Decouplers-3-75m-Decoupler-Issues-%28Return-of-the-Kraken-0-24-2%29?p=1312724&viewfull=1#post1312724

or

Module manager edit: http://forum.kerbalspaceprogram.com/threads/88026-Radial-Decouplers-3-75m-Decoupler-Issues-%28Return-of-the-Kraken-0-24-2%29?p=1313407&viewfull=1#post1313407

[Boris_T_Roach]

My solution to getting those large SRBs clear in time has been the attatchment of 4 seperarons to the SRB as can be seen here

The parachutes are just for recovery

As you can see from the staging, when the srbs are dumped all 4 separons fire blowing the SRB clear of the ship, ok the SRBs sometimes hit each other on the way but not the ship which is the important thing

and thanks to the number of seperaons they dont have time to overheat the liquid fuel tanks, although that does show up when you hit F3 to see the event log.

Boris

Spelling was a optionail curse at my skewl

[Wanderfound]

My solution to getting those large SRBs clear in time has been the attatchment of 4 seperarons to the SRB as can be seen here

http://cloud-4.steampowered.com/ugc/38599918383926908/D378E1B3BAFA55646846843E45A27F2CF4847270/

The parachutes are just for recovery

As you can see from the staging, when the srbs are dumped all 4 separons fire blowing the SRB clear of the ship, ok the SRBs sometimes hit each other on the way but not the ship which is the important thing

and thanks to the number of seperaons they dont have time to overheat the liquid fuel tanks, although that does show up when you hit F3 to see the event log.

See my post above; angle 'em out just a few degrees and you can eliminate the exhaust damage issue entirely.

[MircoMars]

try the seperation on the LaunchPad, because one thing could be the mainengine compressing the tank above it over it's limit. (I don't use FAR, so no idea how much pressure there is on the top of the rocket with that speed and that height, but 200m/s at 6km is a bit fast for my taste)

if that wasn't it, here's an oldschool trick: rotate whole rocket to fling SRBs away

[Roadkill]

@TimberWolfe: Try waiting until you're going faster than 750 m/s to decouple. The decoupler changes to try and get them to work in win64 made them not play well with velocities below the Krakensbane limit.

Are you saying that Squad borked the decouplers in order to get 64 bit out the door?

Do you have a source for this?

Because if that is true, that really pisses me off. I'm sick and tired of Little Timmy ruining this game.

[SRV Ron]

Sepatrons definitely took out the tank with their exhaust. Not a compression issue. I noticed that there is a stability issue with the SRB powered flight as the rocket wandered all around what should have been straight up flight.

Try a ring of eight SRBs instead of the 4x2 ring. Mount them exactly centered to the decoupler. You should be able to position them so there is no clipping of the four engine first stage. Brace the ring at the top and bottom as usual. You shouldn't need bracing between the SRB and central tank. And, you won't need sepatrons as the entire SRB assembly will slide off cleanly so long as you are not turning.

[Zylark]

For my big SRBs I put one Sepatron near the top of the booster in a upwards pointing 60 degree angle or thereabouts. This pushes the SRB down and out whilst at the same time not burning more than a fraction of a second on any given spot on the fuel tank of the main booster. Works every time. One little piece of advice though, if doing the separation after the gravity turn - try and release radially mounted boosters sideways rather than having one each over and under the central booster. Makes the separation much more predictable - especially if also using chutes that trigger with the separation and sepatrons.

[Xavven]

Are you saying that Squad borked the decouplers in order to get 64 bit out the door?

Do you have a source for this?

Because if that is true, that really pisses me off. I'm sick and tired of Little Timmy ruining this game.

TMS posted a link to this thread:

Module manager edit: http://forum.kerbalspaceprogram.com/...=1#post1313407

Look at Claw's post. He basically says that it's a bug that was introduced when Squad attempted to fix in-line decouplers. The radial decouplers are pulling down as well as pushing out. Since radial decouplers are always mounted on one side, i.e. not in line with the COM, it causes the booster to rotate.

I'll test this by mounting a decoupler on the other side of the booster as well. Stay tuned.

[ferram4]

Are you saying that Squad borked the decouplers in order to get 64 bit out the door?

They borked them trying to fix a decoupler issue that was in win64 went out originally went out the door as 0.24.0. Then they tried to fix it because people complained about radial decouplers doing nothing, but it caused its own issues.

Do you have a source for this?

Get an old version of win64 0.24.0. Watch as decouplers apply no force. Switch to win32 0.24.0. Watch as decouplers apply force normally. Switch to any 0.24.2, watch as radial decouplers cause lots of twisting at speeds below 750 m/s.

My only source is paying attention to how behaviors changed between KSP versions.

[Kryxal]

Say, did the OP ever use the F3 menu to check the actual cause of destruction?

[Wanderfound]

Say, did the OP ever use the F3 menu to check the actual cause of destruction?

Yes. Exhaust torching. Nothing at all to do with the decoupler bug, everything to do with not placing the Sepratrons right.

[Xavven]

Welp... putting a decouple on the other side and either firing or not firing it at the time of booster separation didn't seem to have a significant effect aside from the fact that it has mass. I wonder if the ejection force itself has some downward direction to it :/

[Cerberus738]

I don't use the sepratrons anymore. I found spinning the rocket just before firing the decouplers causes the srb to fling far enough out that you don't have to worry about collisions. No more burning of your main tank from the sepratrons! Also less parts!

[TimberWolffe]

Here's a useful little tip for you: drop your throttle to zero just before you decouple (this is easily done by hitting X). If your rocket is running solely on inertia when the SRBs decouple, they will come off far more smoothly. You can throttle back up right after decoupling safely, too.

oh my god thank you so much, they just kind of gently slid down the core instead of slamming into it at 870 m/s

[Kryxal]

I tried the seperatron-at-the-bottom trick on a rocket recently, it didn't work very well ... I just carried on, because the center stack was already out of fuel and I was just waiting on the SRBs, so I didn't actually lose anything!

[SRV Ron]

oh my god thank you so much, they just kind of gently slid down the core instead of slamming into it at 870 m/s

I watch the video again in full screen. Your speed at burnout was OK. I did observe the upper sepatrons torch the fuel can which then vanished a second later. Be sure you are not turning when staging the SRBs and they will always slide off smoothly.