A "living hinge" success - with video

I finally got a hinge printed that works. I’ve tried various methods but either got too thin or too thick or too wide or too brittle… This one is just right. :slight_smile:

It is a small, 0.5mm thick flap connecting the bottle to the cap, with 2mm fillets where the flap meets the bodies. It was designed and printed at a 90-degree angle (see attached pic) @ 0.05mm clear settings. I’m guessing I could up the thickness a little, maybe 0.75mm, but not much more.

I have not done a “how many times can it bend before it breaks” test, but will get to that sometime. I totally messed up my measurements and the cap doesn’t actually fit onto the bottle, so it’s destined to sit in the drawer of misfit 3D prints. :slight_smile:


Nice Gregg, Do you know how does the hinge behave after a few hours in the sun?


Damien, that’s a great question. I’ll put it outside tomorrow and we’ll see.

Damien - I had to wait a couple days for a good sunny day, but I finally placed the bottle in the sun for a few hours and tested it. I had already done 100+ bends on the hinge – 50 in a row, 25 at various times – and after the session in the sun I got 20 in and it snapped. I figured it would become more brittle, so I was surprised it lasted even 20 bends. :slight_smile:

I am very curious as to how long it would have laste with a UV resistant coating applied.

Hi Donald, I am doing something similar to Greg and was wondering if you had any examples of a UV resistant coating that I could try out. Many thanks Toby

I found a PVC paint called Superflex which is also UV resistant, I was going to give this a go

Hey Hunt,

I use a clear coat from Krylon:

It works well but the model needs to be thoroughly cured before applying the spray or the surface will remain indefinitely sticky. My test models are a year old and I can still hang note cards from them.