Diffuser sheet ideas?

[marcmerlin]

I’d like to add a thin plastic sheet in front of my RGBpanel to

1. protect the LEDs (I’ve already has one ripped off in transport)
2. be a bit larger than the panel so that I can round the corners and avoid my existing corners that will poke your eye out if you put it in the wrong place
3. maybe act as a small diffuser (so it would not be completely transparent).
4. be reasonably light/flexible but not break easily

With my neopixel panel, I actually only use tracing paper, which works fine, but wouldn’t act as a protective layer in the RGBpanel case, nor can it extend past the corners to add protection.
For the rear, I have the panel be inside my shirt and use the white shirt as a diffuser/protection, but that won’t work here either as the RGBpanel is too thick/pocky for me to want to wear it that close to my skin
So, some kind of plastic diffuser sheet on top of the panels is probably what’s best in my case. Any ideas?
(big bonus points for something I can order online of course)

[Louis]

Most of my diffuser thinking has been around non-wearable projects, where weight and rigidity and sharp corners aren’t a problem.

I didn’t find anything appropriate in my diffuser bin.

Here’s a few links that may have interesting ideas:

• https://forum.makerforums.info/t/translum-diffusion-again-what-you-see-on-the-focussed-photo-is-a-cheap-dull/60588
• https://forum.makerforums.info/t/i-made-a-wee-compilation-of-my-most-nature-themed-patterns/66275
• https://hackaday.io/project/20121-i-love-lamp/log/59085-led-diffusion-experiments-some-results
• https://www.adafruit.com/product/3580

I use Acrylite Satinice 1/8" 3mm sheets for most of my projects. You could put a rounded edge on them. They’re not flexible though, acrylic can be brittle.

I don’t have any appropriate samples to try, but I was thinking a translucent silicone mat might meet your criteria.

Here’s a picture of some thin packing foam from a recent Aliexpress order. It tears easily from the edge, so maybe not as robust as you’d need.

Think about layering something soft under something more rigid, like a clear file folder that will hold its shape, and potentially hold the diffuser in place.

[Louis]

Also, think about clear silicone furniture corner bumpers for childproofing, could be a quick fix for the sharp edges

[marcmerlin]

I use Acrylite Satinice 1/8" 3mm sheets for most of my projects. You could put a rounded edge on them. They’re not flexible though, acrylic can be brittle.

Thanks for all the links, on that note, believe it or not, I’ve actually had non sober people bunch me (twice) for reasons I don’t understand. It wasn’t a huge punch, but enough to break something that’s brittle. Also, it needs to survive a plane flight, so it can’t be glass like

Will look at your other suggestions, thanks much.

[marcmerlin]

I also got some helpful answers on https://www.reddit.com/r/FastLED/comments/b5s3es/flexible_diffusing_plastic_sheet_contact_info_for/
For now, it looks that what I’ll do is a combination of 2 things.

I ordered both of

https://www.amazon.com/dp/B00XAC19YG?tag=bizzi0d-20 and https://www.amazon.com/dp/B07F3NT32S?tag=bizzi0d-20, and interestingly they are both the same material.

It is flexible and light enough (not super light, but it’s workable), and is probably what I will be using as protection.

To be honest, the diffusing effect is quite light unless I space the sheet a little bit away from the display. In other words, if I put it right on top, there is almost no diffusing effect, but maybe if I sand it, it’ll work better, or somehow if I can install some spacers…

https://www.amazon.com/dp/B00CNE94RG/ref=cm_sw_r_cp_api_i_q0MMCbD4FZX6K is not useful on its own, but as a layer between the panel and the cutting mat material, it looks like it will work to make diffusion work better.

[Louis]

Had some more ideas:

• Polycarbonate instead of acrylic
  • Much stronger
  • Not as easy to laser cut
  • Might be able to drill the holes?
  • Usually clear, so you’d need something else for diffusion
• BOPP Film
  • This is really thin, translucent with light behind it, but completely opaque without, and transmits light well. I thought it looked great with a matrix behind it
  • It’s too thin to have any structure on its own, so you need to sandwich it between two other layers. I tried experimenting with using adhesive to attach it to acrylic but ended up with bubbles
  • I used this on my first SmartMatrix product that I sold at maker faire in 2014. It’s difficult to work with in large quantities, so I avoided it for future kits
  • http://docs.pixelmatix.com/SmartMatrix/projects.html#smartmatrix-projects-aurora-display-bay-area-maker-faire-2014
  • I think I got the BOPP film from something like this: https://www.aliexpress.com/item/20-30cm-BOPP-Pearl-Film-ZipLock-bag-100-X-Translucency-Plastic-bags-side-clear-White-pearly/32651751628.html
  • I doubt you’re going to find a bag big enough for your display
  • I’ve also purchased this in the past, it’s much thinner than the BOPP bags: https://www.amazon.com/gp/product/B0000E2RGH/ref=oh_aui_search_asin_title?ie=UTF8&psc=1

I see you already made some progress on diffusion, so maybe this isn’t the direction you want to go, but thought I’d share anyway.

[marcmerlin]

I did a hybrid approach. Took some pictures, will need to post them when I have a bit of time.

[marcmerlin]

I used a combination of two solutions. Here is the end result:
http://marc.merlins.org/perso/electronics/post_2019-04-09_Trying-Diffusers-for-RGB-Panels-run-by-SmartMatrix_GFX.html

I’m lucky that the kitchen matt was exactly the correct height for 3x 32x64 panels in P4.

[Louis]

Glad you found something that works, and thanks for sharing your solution!