Why Do Things Just FALL APART In This Game?

[ecat]

This is the symmetry problem I posted about earlier

http://forum.kerbalspaceprogram.com/showthread.php/37397-Symmetry-Problem

[Mr Shifty]

ecat, I just had to go check... Went to the VAB with my lander and found that there were TWO drills in the two places I put them. No wonder they weren't attaching properly.

I just had this happen yesterday. TWO probe cores with a bunch of antennas attached, overlaid exactly on top of each other. I didn't discover it until I was in space, but they luckily haven't caused any problems. I also am using EdTools.

[NeoMorph]

I went back and checked some ultra unstable rockets I had given up on... I found one which kept exploding on unpack but I could never figure out why... Added lots of launch stabilisers, added a ton of struts and still booom. On deeper inspection though I found a pair of fuel tanks INSIDE of the central orange tank. I think you are right about the symmetry problem ecat. It's adding extra items in strange places.

I've decided I'm clearing out my build lists and starting from scratch... and double checking every darn part now.

Edit: Well I build the same lander from scratch and made sure there were no duplication in the symmetry parts. Landed perfectly FIRST TIME.

Successful Drilling Mission On The Mun

Edit 2: OH DEAR... landed fine... but I deployed my drills before deploying my solar panels... RAN OUT OF POWER LOL. Lander is DEAD!

Edited June 23, 2013 by NeoMorph

[Mr Shifty]

This must be why one of my favorite launcher subassemblies stopped working: always gets to 1000m and then turns left on its own, loops a few times and crashes into the VAB.

[SRV Ron]

Things that just fall of are the main reason I use modded struts now. Otherwise, I stick to the stock strut. But It would've taken an insane amount to prevent the LV-N falling from my latest creation when the main 'chutes open fully.

Watch the G meter jump when the main chute fully open and you will understand why the heavy LV-N falls off at that point. If you can provide a way of slowing the craft's descent down just before main chutes fully opening, some form of retro rocket firing, that would eliminate the high G jerk that causes parts to fall off.

[TooManyErrors]

It looks like all you are complaining about is the modded parts. That might be your problem, the mods, not the core game.

Its not just mods. You know the large RCS tank? That thing will fall of really easily. Also the Rockomax tanks and engines are very prone to randomly fall off if you don't add struts.

[zarakon]

KSP is, by default, EXTREMELY strong. I had a small problem in my mun rover landing design.

Maybe the issue is that joint strength doesn't scale with the power or mass of the parts?

So a connection between two little probe-size parts will be incredibly strong relative to those parts, but connections between large Rockomax fuel tanks or Mainsail engines is too weak to handle a gentle ascent or even standing on the launch pad without adding a bunch of struts. Bigger parts should have stronger built-in links between them.

[arq]

Edit 2: OH DEAR... landed fine... but I deployed my drills before deploying my solar panels... RAN OUT OF POWER LOL. Lander is DEAD!

Haha I have that happen to me all the time (or leave a probe in orbit for awhile and forget to deploy the panels). I always put 2 of the small fixed solar panels on my probes now, so that they will eventually hit kerbollight and be recoverable.

[ecat]

Edit 2: OH DEAR... landed fine... but I deployed my drills before deploying my solar panels... RAN OUT OF POWER LOL. Lander is DEAD!

Whoops!

Now, that is a PEBKAC issue

[Virtualgenius]

Everytime I approach my station it starts wobbling and just flies appart its a struted to the whazoo have no idea why it happens

[Tiron]

Watch the G meter jump when the main chute fully open and you will understand why the heavy LV-N falls off at that point. If you can provide a way of slowing the craft's descent down just before main chutes fully opening, some form of retro rocket firing, that would eliminate the high G jerk that causes parts to fall off.

There's a solution for that. It's called a 'Drogue Chute'. Produces less drag and opens at a higher altitude, specifically designed to prevent this sort of thing.

[karolus10]

This is problem with part nodes mechanics, they aren't really stiff but are very strong and wobble very much.

For now, struts are only existing remedy :/.

[tom1499]

Funny, because the Apollo Lunar Module's were so weak they were practically made of tissue paper. You could poke that thing with a pencil and break it.

[Dravin]

Dont I know it... had a rocket all ready to go to orbit, a nice hefty lifter with a nuclear engine powered payload cradled inside the lifter (I like compact designs) and when the physics loaded in... my nuclear engine simply fell off, it hadnt touched the ground nor does it have things dangling it, it simply fallen off.

I was like oh nice, yeah just drop off why dontcha its not like I needed the bloody thing... really

I've had similar random failures on the launchpad, I figure it's just a random glitch. I do admit it is annoying to have a lifter you've used several times without incident just fall apart on the launch pad (sometimes quite spectacularly) and then work perfectly fine by reverting to launch. Such are the vagaries of early access I suppose.

[NeoMorph]

Wow... Thread res!

I've found that 21.1 is generally more stable... but I still have an intermittent glitch where my rocket unpacks on the launchpad and the boosters fall off and then self ignite and fly off to the heavens. Reload it several times until I get a stable unpack and then I can take off.

[HeadHunter67]

Welcome to a world that's never heard of welding, or rivets... they snap parts together like a model for 10-year olds, and hope it holds. Struts are the only answer they've invented for reinforcement.

[littlebattler]

Welcome to a world that's never heard of welding, or rivets... they snap parts together like a model for 10-year olds, and hope it holds. Struts are the only answer they've invented for reinforcement.

But a jungle of struts is better than rivets anyways.

[Skorpychan]

They've gotten better with the last update, but my eve mission still wobbled when I sent it up today (admittedly, not as bad a case of the wiggles as that lifter used to have), and it's still a world where rocket parts are just jammed together.

The main thrust engines on my interplanetary transfer stage are snapped onto a fuel tank on each side, which is held onto the main fuel tanks by a girder and an assemblage of struts. I stuck batteries and RTGs over each engine, creating 5+ ton sub-assemblies, held together by struts, hope, and habit.

Hell, my first Mun landing ran out of fuel, smacked into the ground, broke the lander legs off, and fell over. Everyone survived, they were even able to go on EVA once I made sure it wasn't sitting on the hatch.

And one of my first rover deliveries ended up sat upside down on the surface of the Mun, having failed to right itself with RCS, pod torque, and wiggling the landing legs.

[automcdonough]

this happens to me usually only during launch, and only when it's 700+ in weight. the physics just gives up, random fails everywhere. those stages independently are perfectly fine.

[HeadHunter67]

But a jungle of struts is better than rivets anyways.

It may be more "Kerbal-y", but it's hell on the computer and it gets... unsightly.

[Whackjob]

But a jungle of struts is better than rivets anyways.

Approves!

[Thorbane]

That ... thing ... is completely insane. I like it. Must be a giant pile of lag though.

[Whackjob]

Yeah, but worth it.

OP, I believe what you're experiencing is something I run in to on a daily basis with my big builds. I believe it's something of a resonant stress effect. Imagine waves of force bouncing from one end to another, from different sources, and every once in a while those waves converge at a single point. POP! Off goes an engine cluster! It is my worst nemesis.

However, the solution I've found is struts. Now, not your normal application of struts, but rather a sort of external structural strut carapace. Giving those waves of force more connections to spread out across seems to resolve the issue. It is labor and FPS intensive, but it gets results.

As an example, my latest Arkingthaad lander has such a carapace:

It holds together like a champ.

I extended that support down to the legs. Because weight.

Underbelly gets the same treatment. The undercarriage doesn't extend to the legs, because I want that structural support to be above. The center portion pretty much hangs from that carapace.

Edited August 9, 2013 by Whackjob