Pinpoint / very small radius LED lights. - Page 1
Forum section: electronics / projects

author: Youkai
author_rank: Regular Contributor
timestamp: April 21, 2020, 04:56:01 am
content: I saw this post on Reddit about a UFO lamp/night light:https://www.reddit.com/r/3Dprinting/comments/g4x2tg/ufo_led_test_success/?utm_source=share&utm_medium=web2xI want to do something similar and was talking to my Wife about it. She mentioned the "Wishing tree" in "True and the Rainbow Kingdom" (Netflix) which my 3 year old daughter is into. I thought that was a great idea. My plan is to have a semi-transparent shell of green PLA for the leaves and set a NeoPixel stick or similar to light up the inside of it and make it glow.The question is what to do about the wishes? As you can see from the attached pictures the wishes live in the tree and are little yellow balls. So I need a way to light up a small/specific section of the shell and make that yellow. The shell will probably end up being a bit smaller than a basketball. My printer has a 200cm3 print volume so when I print the "leaves" it has to fit inside that. I'm thinking that if there were something like 20ish yellow spots throughout, that this would be sufficient.My first thought for how to light it was to put a NeoPixel strip "laying flat" in the bottom of it pointing up and have that illuminate the interior of the tree. But doing that there is no way to have specific narrow regions of color.Could I do some kind of fiber-optic bundle with a yellow LED on it and then rout the fibers to various places on the shell for the pinpoint yellow lights? The only other thing I can think of is if I had some kind of individually addressable LED "blanket/grid" with pretty narrow spacing. Then I could make all the lights green with the exception of the ones I want to be the wishes.I'm just gathering ideas at this point and don't know what I don't know. So please feel free to suggest other solutions if you have any ideas. Thank you!

author: ANTALIFE
author_rank: Frequent Contributor
timestamp: April 21, 2020, 05:05:27 am
content: Cool ideaI have a feeling using fibre optic cable is the easiest way to manage this, compared to say wiring up a bunch of addressable LED's. I don't think your printer will have any issues with printing channels through which you can push fibre optic cable through

author: tooki
author_rank: Super Contributor
timestamp: April 21, 2020, 08:09:17 pm
content: You can even buy off the shelf “starry sky” ceiling kits with the fiber optic bundles.But for something this small, go to a toy store or museum gift shop and buy one of those fiber optic flashlight toys and harvest its fiber bundle.Or print the tree with green plastic, and drill tiny holes or have them printed in the model. Then light the whole tree with red+green blended yellow light (not with true yellow LEDs!), and the holes will allow the blended yellow out, while the green plastic will filter out the red light and make it appear green.

author: Youkai
author_rank: Regular Contributor
timestamp: April 22, 2020, 03:36:13 pm
content: Quote from: tooki on April 21, 2020, 08:09:17 pmThat's a really interesting idea. I was kind of hoping to have the wishes twinkle but I really like how simple that is. I'll consider it if the fiber optic doesn't work out.

author: themadhippy
author_rank: Super Contributor
timestamp: April 22, 2020, 04:38:06 pm
content: The old school star cloth twinkle effect involved some very technical electronics, a slotted disc was mounted between the light source and fiber bundle,the heat from the lamp made the disc spin.