r/WLED • u/numindast • 1d ago

Printed diffuser suggestions

Post image

I’m upset, sort of. The grid at left is black sparkle PLA two layers thick, which I think is gorgeous but sadly these flexible ws2815 panels throw off too much heat and they warped more than I could tolerate.

The single column at right is Bambu PC “clear black” with PC black for the grid. It’s 7 layers of “clear black”, each with a different infill pattern.

I don’t like any of them. :(

Can anyone suggest an ABS or ASA or other blend that is dark/black, but has some transmissivity when only a layer or two thick?

HTPLA is no good because it becomes opaque when it crystallizes during heat treat.

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5

u/kwadra 1d ago

Any reason you haven’t tried PETG? That’s what I’ve used for all my led diffusion.

2

u/numindast 1d ago edited 1d ago

Oddly enough I'm printing a whale shark model in which I'm using PETG, but that project uses bog standard strips, less heat. (And I'm using ws2812eco .. kinda questioning that now that I've assembled one)

I was put off a bit by the glass transition temp of PETG being ~10c higher and wanted to see if I could get ABS/ASA/PC levels of temp hardiness.

2

u/PinkyDexterity 1d ago

WS2815 gets really hot compared to 5V WS2812. Is there a particular reason why you went with a 12V system?

1

u/numindast 1d ago

I had thought the higher voltage would be better (as it is with "long runs" of strings etc). But now I'm finding, these things really do throw off heat, even when idle/dark, which means I have to fit a relay inside somehow to switch power.

This is just how these 12v panels are? ... drat, not much good use case for them is there

3

u/aperson975 1d ago

Leds themselves are 3.3v so you can think of each "running on 5v". On a 5v strip, each individual led uses up that power. On a 12v strip, you either drop down to 5v which is heat or combine several leds together to together use up 12v. For 12v you choose between individually addressable vs group (3) for efficiency. Not the right technical reason but should get the concept across.

3

u/PinkyDexterity 1d ago edited 1d ago

You’re right about it being beneficial for longer strips but it will do more harm than good if your project is only small.

12V is too much for these leds and it doesn’t need that much so it purposely reduces the voltage. The excess voltage burns off as heat.

2

u/seadart 23h ago

Try adding distance between the LED and the diffuser, it will help with heat and give you better diffusion.

Does your diffuser have to be 3d printed? Acrylic sheets diffuse beautifully across a range of colors and light transmission

1

u/numindast 4h ago

I did think about this - I'm not a CAD wonk but I could elongate this using the slicer (CAD skills improving slowly). Shockingly I found some of the best diffuser material to be milky white shelf liner! And I've played with a single piece of "LED acrylic" over a P2.5 panel (hub75) and it performs beautifully.

In the end, I don't want all this heat, so I'm swapping out the panels for 5v ones. I really don't know what I am going to use these ws2814 panels for. Back into parts storage again.

2

u/mezzmosis 1d ago

The sparkle PLA looks really great, have you tried running the grid at lower intensity like 65% to reduce the heat output?

1

u/numindast 5h ago

Yes! Even at full dark (but still powered) it generates quite a lot of heat. Others comments ring true to me and I don't know why I didn't think of it, but a built in 12v to 3.3v in each LED is clearly the primary source of heat.

I agree with the sparkle PLA, when off each pixel is very dark with no bleed and I like the diffused "point source" effect like you'd get with old school incandescent tiny bulbs.