At first glance i was horrified, as 3dprints aren’t known for their strength…
Looking into it, i’m still horrified. It’s a 3d printer plastic type i haven’t tried yet, but it still seems absurd to use printed plastic for a part subjected to such high g-forces…
Have seen a lot of youtube vids with people printing turbines/propellers for RC model planes, but nothing ever close to that size or speed…
A solid molded part possibly, but 3d-printing seems rife for adding many micro-faults into the structure that’d induce failure when run at extreme RPM…
I actually had a fridge taped shut like that for that very reason. It went crazy and started heating things up instead of cooling them down. I lived on the 13th floor of a tower block & it was a while before I could get any help moving the massive, smelly bastard outside. It… wasn’t good. Hopefully, his is taped shut for aerodynamic, not biocontainment reasons
maybe could try re-orienting the blades on the printer bed , makes quite a difference if the layers are from the root to the tip of the blade , or from say , side to side or back to front , maybe still not enough for this application , but orientation when printing is often one’s friend ; also , much higher strength plastic feed filaments are available ! nylon might be a good choice here , or maybe a glass or carbon fiber filled , maybe polycarbonate ; or maybe just use the plastic prints as a mold in a ’ lost plastic ’ casting process
You’ve not used PETG? It’s my second favorite plastic (after PLA). It does everything that ABS does, but with no warping, super strong layer adhesion (pretty much isotropic), no toxic gas release when heating, and a few more. Oh, it’s naturally clear so you can get very pure translucent colors which you can’t get with ABS or PLA. It is more flexable than PLA, but slightly less so than ABS.
From the video, it looks like it was printed with the ‘back’ on the bed and built up from there. That’ll give you the highest strength in the correct direction, so they did that right. I think that addresses what @edthehippie brought up.
As far as what better filaments could have been used, there are a ton of them, so they all require a lot more out of the printer–higher hotend temps, hardened nozzles, heated enclosures, special bed adhesion materials, etc. PETG is a very good choice for this application. But, it does tend to shatter when it fails–which can be somewhat messy as the video shows. Keep in mind that a lot of the stronger filaments (PC, Nylon) sacrifice rigidity for strength. Sure, they take more force before they break, but they also stretch more–which isn’t particularly good for this application. I’m pretty sure it’s the cause of this failure, but there doesn’t seem to be sufficient instrumentation on the engine to tell–a few microphones glued to it would have been informative.
I’m relatively new to the hobby (just under a year), have only tried a few PLA varients and some TPU, i shall make sure to add in some PETG next time i order new reels then
I hope you have a positive experience with it. If you’re new to printing, you will want to be aware of a few things. You need to print PETG hotter than PLA–235C or so depending on the specific filament. You will also experience more stringing, so you’ll likely have to tune your retraction settings better than you already have. If your machine is a Bowden, you may find the process somewhat frustrating. But it may improve the quality of your PLA prints as well.
Feel free to message me if you run into any issues, I’m always glad to help.
My dad was doing a thrust test on his plane once. The propeller accidentally sucked in a trash can, exploded the propeller, bent the camshaft, and sent propeller parts through the wall of his garage.
