With lot of Trial and Error I believe I came up with most functional and most minimally sized 3d printable screw for the Bambu (lot of Bambu users here) machine at standard .2mm layer with standard .4 nozzle.
If you print without infill, just solid plastic it should be strong enough for most projects.
This design is especially made for this phillips screw, CR-V 2.5, it should fit like a glove.
I came up with this design because the previous 3d printed screw broke, had a hard time taking it out. I realized if I create continuous through slots, even if it breaks I can still easily unscrew it.
Like a nimrod I came with this because I embedded an 3d printed screw in my camera, broke it and couldn’t take it out. Had a bright idea of using Paint Thinner to melt the PLA in the metal socket but somehow it got through and fried the motherboard.
From what I know PETG is bit stronger, but to be honest I don’t think I ever used PETG, it’s something I heard.
I found Matte PLA the weakest, this will hold matte pla.
My goal wasn’t to create the most robust thing, It just needed to withstand basic uses and when it brakes you can still get it out. I had this break on me many and it was easier to get it out.
I think this is a step above press fit, below higher grade materials.
But if you really needed strength I would embed metal nuts but maybe this better than Superglue.
An alternative is Thread Inserts, I find them useful for demos that would be assembled and reassembled repeatedly. If thoughtfully applied they even become be quite strong inserted hot (with or without dedicated soldering tip) or just simply glued into PLA.
Brass thread inserts work well as long as they are not positioned too close to an edge. I found that when heating the insert (with soldering iron) it melts about 3-4mm around the insert so allow some space.
I’ve mostly used PLA for my daughter’s little train projects, and I agree—it doesn’t need to be super strong, just durable enough for basic play. I’ve heard PETG can handle more stress over time, so maybe I’ll try it for parts that see more wear.
I use PC polycarbonate for higher stability up to 110°C (230°F) printing at 250-270°C. Also has a higher Shore at
D 90–95, but it can be more demanding to print. Another unrelated tip is to use a hot-air soldering station for easy and well controlled small adjustments or inserts.
Edit; I found PETG is better of than PLA for kids. Also this: ‘Polycarbonate is generally considered safe for kids, especially in products like eyeglass lenses, which are designed to be impact-resistant and protective. However, caution is advised with polycarbonate containers that may contain bisphenol A (BPA), as exposure to BPA can pose health risks to children’
Thanks for pointing out the comparison between PETG and PLA for kids’ products, as well as the BPA considerations with polycarbonate. That’s super helpful for planning safer and more durable prints!
