weird explosions with seperatrons

[magnemoe]

I'm playing around a bit with drag racers and like many other I end up with seperatrons for power.

This works well an quick build managed 606 m/s, however trying more boosters casue the car to explode.

Here the car blows up Hollywood style then I drop the command module.

It don't make any sense, the change from the working version is the 8 seperatrons at the back wheel grinder.

Does seperators has an critical mass like plutionium?

[vexx32]

Mmh. This is probably better suited for the Gameplay Questions section... Yeah, I'll move it.

As to the issue itself... looks like the rearmost separatrons could be in the path of the other ones exhaust fumes. That'll cause overheating and potential explosions...

[celem]

Wait, does it blow when you light it or just when it gets a physics-drop? Wondering if you typod and meant that this blows on initial deployment. If so then its possible that the mass of the new seperatrons means it now breaks apart and needs a strut or 2. They are pretty light tbh, but who knows? They are little bombs, you dont want them knocking into each other or other components. Also if something is clipping weirdly and tries to break off then it will bang if its a srb like a seperatron.

Theres certainly no hard-cap on the number of any part that you can use. Some can overheat as vexx mentioned, but not without being lit.

Edited March 10, 2014 by celem

[magnemoe]

Mmh. This is probably better suited for the Gameplay Questions section... Yeah, I'll move it.

As to the issue itself... looks like the rearmost separatrons could be in the path of the other ones exhaust fumes. That'll cause overheating and potential explosions...

Thanks it fits better in questions.

And yes it might be issues with overheat however the craft blows up before the engines are fired.

It might be an clipping issue however the seperatrons don't clip each other and the 8 in the back is put on top of an grinder each.

[celem]

I dont suppose theres anything useful in the f3 output? Maybe the Kraken just takes offense at the design. I have a couple of saved ships I cant launch without them bombing on the pad. All were successful designs that one day got tweaked just the wrong way and now wont load without exploding. I would suggest reverting the change since it is a small one and then reapplying it manually (i.e. dont use a subassembly, rebuild the back girder) and test it again.

edit: only other thing i can think is seperatrons knocking each other; your wheels are avionic so dont have variable suspension, this means the centre rib drops a little when it lands on the runway at launch. This will cause the wheel-mount girders to flex a little and those seperatrons are really close together...possible. I-beams flex less, might work

Edited March 10, 2014 by celem

[magnemoe]

Wait, does it blow when you light it or just when it gets a physics-drop? Wondering if you typod and meant that this blows on initial deployment. If so then its possible that the mass of the new seperatrons means it now breaks apart and needs a strut or 2. They are pretty light tbh, but who knows? They are little bombs, you dont want them knocking into each other or other components. Also if something is clipping weirdly and tries to break off then it will bang if its a srb like a seperatron.

Theres certainly no hard-cap on the number of any part that you can use. Some can overheat as vexx mentioned, but not without being lit.

Worse it explodes then I drop the command module at back, for the initial test runs I did not bother moving Jeb into the rover seat in front.

With 5 stacks of 6 seperatrons down the main axis the car is stable, with 6 its blows up then I drop the command module with 8 it blow up on physic load.

Find it very weird, has tried multiple rebuilds all with the same problems.

[magnemoe]

I dont suppose theres anything useful in the f3 output? Maybe the Kraken just takes offense at the design. I have a couple of saved ships I cant launch without them bombing on the pad. All were successful designs that one day got tweaked just the wrong way and now wont load without exploding. I would suggest reverting the change since it is a small one and then reapplying it manually (i.e. dont use a subassembly, rebuild the back girder) and test it again.

edit: only other thing i can think is seperatrons knocking each other; your wheels are avionic so dont have variable suspension, this means the centre rib drops a little when it lands on the runway at launch. This will cause the wheel-mount girders to flex a little and those seperatrons are really close together...possible. I-beams flex less, might work

I think your idea about weight and suspension might be correct, the central stack start to oscillate forward and back a couple of times before exploding.

Anyway I have one design who reach 700 m/s only thing missing now is to get the braking to work

[Geschosskopf]

I think your idea about weight and suspension might be correct, the central stack start to oscillate forward and back a couple of times before exploding.

Anyway I have one design who reach 700 m/s only thing missing now is to get the braking to work

Actually, airplane wheels do have variable suspension, but Celen is correct about the structure possibly flexing. But you mentioned it explodes when you drop the capsule, so I'm thinking the flex is happening at that point, not when physics drops it. Looks like you're using a radial decoupler for the capsule, and that the capsule might go sideways into the rear wheel pod, plus the separation force causes a sideways torque on the rover.

To avoid this, you can try adding some launch clamps. Put clamps on the rover itself and on the capsule. Connect the capsule to the rover with one of those blue stack separators instead of a radial decoupler. The reason for using the blue separator is that its forces in both directions are about equal and so largely cancel out.

The launch process would then be as follows:

1. EVA the Kerbal from the capsule to the seat
   
2. Fire the separator between the capsule and the rover
   
3. Release the clamps on the rover. The blue ring will now either fall to the ground and explode harmlessly or will be just sitting on the back of the rover ready to fall off if it move.
   
4. Drive away. If the blue ring is still sitting on the rover, it will fall off and explode harmlessly at this point.
   

[Vanamonde]

What does the F3/post-flight report say is the first thing to go wrong?