I have a problem with my International Space Station 21321 set, all the blue clips that hold the panels to the main beams are crumbling, and weakened enough that I wake up to panels on the floor. I have no idea why this is happening, but hoping someone can help? Ideas I can do different to prevent it after I replace these parts? It seems to effect all the blue clips not just the big ones, even the little pod lost one of its solar panels :(
Some details, it's probably 4 years old now. I keep it on display but not under glass, in a 72f room. I have difficulty keeping it totally dust free as it's very fragile to begin with, but it's never really been touched otherwise.
There are what? About a dozen different plastic types Lego uses? There might be a batch of plastic that was used that is slowly shrinking over time from off-gassing. (Typical bricks are ABS which don't have that particular problem.)
There might be a defect that someone else is aware of, but you might need to replace the connectors or glue them. Heck, you just need to fix the friction fit so creative use of PTFE thread tape might work.
(Not a Lego expert, but I do my research into plastics and such for other reasons. I want to guess that it might be the PMO (Delrin) that is causing the issue which is absolutely not approved for use in spacecraft.)
Edit: Clarification on the PTFE thread tape use. For those who are unfamiliar with it, it's not sticky and does not have any glue on it. If anything, it's going to be a bit more slippery than other plastics. If you had two bricks and put a layer of PTFE tape between them, it's would be thin enough to act as a wedge between the bricks to fix a friction fit but you should still be able to pull the bricks apart easily. You would need to experiment though.
This is an informative answer, unfortunately it's not a matter of being loose or resizing. The clips are kind of disintegrating under the weight of supporting the piece to the crossbeam.
Ok, I misinterpreted "disintegrating" in your original post. It's unusual for parts to just crumble, so I took that to mean that parts were just falling off the build. My mistake.
Yeah, it would likely be a factory defect in the plastic. (Too much plasticizer, too little or even an incompatible dye, maybe.) Lego would probably be receptive to sending you replacements in that case as they are probably fully aware of any bad batches of plastic they had by now.
Most home windows filter out a majority of UV light from sunlight but not enough to completely prevent plastics from degrading slightly faster. Even if it got just a couple of hours of direct, filtered sunlight per day, that may have caused an issue over 4 years. (I have had plastics sag and crumble because of this over a similar time span, actually.) Just something to be aware of.
(Ozone loves to munch on plastic as well. If you have an ozone generator next to your model, that would be an issue. Some home air purifiers generate ozone, btw.)
It does get a few hours of sunlight in the morning, and I do have a portable air conditioner in the room to keep the temps stable. I suspect that could have the same effect? Hmm.. thank you for the leads I very much appreciate it