I am designing a device that contains an LED and some TPU buttons. I thought it would make sense to have the LED shine through just a few layers of TPU. Is that feasible? It is just an indicator LED. Or does translucent grey TPU filament exist somewhere?
It will be my first experience with TPU anyway. What are the caveats? I have P1S. I already understood that I will need to side-load it (not through AMS) and keep it dry.
If you set the layer height thin enough, any filament has a certain amount of transparency. This is evidenced by the large number of transparency tests out there.
The secondary factory is of course the filament color and type. As an example, light color filaments are obviously more transparent. What you will want to experiment with is printing out some samples and then for your button, use a negative cylinder just under the surface where you want light to display. You can vary the size too in order to allow for more light to flow through.
Yes, experimenting will have to be done beforehand indeed.
Thanks for showing the transparency tests, have not seen those before, but yeah, never looked for it 
As long as the TPU is translucent and the LED is not the “complementary” color to the TPU (meaning red TPU with a green or blue LED won’t work as well as with a red LED), it’ll work just fine. More a question of how bright the LED needs to be.
I light stuff I 3D print all the time. The problem is rarely about “will the LED be visible” and more often about “how do I eliminate the light leakage through other areas of the print”.
Red PETG base with 5 walls, blue LED on left, red(ish) LED on right.
Thanks. How thick is the 5 loop wall in total? PETG in itself is a transparent material I think. All opacity has to come from the coloring. I am not sure if that counts for many materials, like TPU though.
0.4mm nozzle, so 2mm.
PETG is significantly more opaque than most TPU. A few cm would probably not be too much TPU.
The key for maximum brightness is to make sure the TPU color is transmissive for the LED color. Easiest way to achieve that is to use clear TPU or a color TPU that is similar to the LED color.
Like in my pictures above, where the PETG is much brighter when the LED has more red than when it has more blue. There’s a little microcontroller in my print that changes the LED colors continually. The colors at the blue end of the spectrum don’t show through the red PETG as well as colors at the red end of the spectrum.
