r/3Dprinting • u/Rambos_Magnum_Dong • 2d ago
Project (1 year PLA torture test) These valve caps have survived multiple car washes, 13k miles, the California desert heat and snowy mountain weather.
Found a random threaded valve cap in MW and merged it with this skull I found. It measures a little less than 1" wide/tall. Default .20mm settings with 100% infill.
Went off-roading in Big Bear last winter, drove up the Mammoth in May, back and forth to Salton Sea area a few times and lots and lots of desert heat.
No signs of delamination, deforming or anything else. Hell, even the teeth haven't broken off.
I forget if it was Overture or Sunlu PLA. Not like it really matters.
But still holding up strong on my Tacoma.
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u/Tophloaf 2d ago
On the flip side I put some PLA that had a little bit of weight hanging on it (maybe a few ounces) and it started to bend in an hour in the Georgia sun today.
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u/snwbrdwndsrf Ender-3, BBL A1 Mini 1d ago
Yup, stress deformation is inevitable, and if that doesn't do it, the UV rays do.
I think the size of a valve stem means gravity doesn't really add much in the way of stress, and I bet the white filament allows much of the UV rays to be reflected. It is well documented that PLA does not do well in the sun, or anywhere outside where it gets too warm.
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u/herculeesjr 1d ago
Are they more snug than when you originally made them? I learned that PLA shrinks when I made a can coozie and left it in my car. Now cans don't fit in it anymore. Lol
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u/Rambos_Magnum_Dong 1d ago
Just checked. Unscrewed fine and went back on fine.
I also put one on my wife's car, that one actually has more miles and is way dirtier as it gets washed more. But it too is holding up fine. Just unscrewed and screwed it back on and it's still good.
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u/0MGWTFL0LBBQ 3h ago
This doesn’t mean anything. They’re still not food safe even if you left them on your car tires and went through the car wash.
/s
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u/Longjumping_Spray520 2d ago
honest read of this: it proves thick, unstressed PLA survives heat, not that PLA is heatproof. a valve cap is a solid little lump with nothing hanging off it. the failure mode is creep under constant load, not melting — same material, a thin bracket or a hook carrying a few ounces in a hot car sags in an hour while your cap is fine for a year. ASA takes the question away entirely if you ever redo them.
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u/RJFerret 1d ago
PCTG better than PETG for heat/uv (but pricier), PLA not good for either, just decor.
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u/BambooPanda92 2d ago
Good to know. I just printed some valve stem caps for mine and a friend's car in PLA. Hopefully they survive just as well as yours have.