After years of being a software developer, [Chris] was excited to get back into embedded development and we’re glad he did. His 3D printed lithographic moon lamp combines a number of hacker and maker skills, and is sure to impress.
3D-printed lithographic moons have gotten pretty popular these days, so he was able to find a suitable model on Thingiverse to start with. Gotta love open-source. Of course, he needed to make a few modifications to fit his end design. Namely, he put a hole at the bottom of the moon, so he could slide the LED and heatsink inside. The 3 watt LED is pretty beefy, so he definitely needed a heat sink to make sure everything stayed cool.
Otherwise, the circuit itself is pretty straightforward. He has an ESP32 to drive the RGB LED through a transistor, and fitted the components onto a custom-designed circuit board to ensure everything stayed neat and organized. You don’t want a ton of loose wires and breadboards cluttering this build. Since he used an ESP32, he was able to create a simple web interface to control the color of the LEDs. Gotta make it connected somehow, right?
What’s great is in addition to the project write-up, [Chris] includes video tutorials, walking the readers through each individual step of the build. By doing so he really makes it easy for readers to follow along and reuse his work. If you’re still looking for ideas, one of these could make a really good Christmas present.
3 Watt LED? I’m thinking not a good project for PLA right?
a 100mm sphere has a surface area of over 300 square cm, so <10mW per cm^2
depends on how fast it can dissipate it
Also not all the energy is absorbed, quite a lot makes it out.
Why would anybody ever want to use PLA instead of PETG or PCTG? I don’t understand why that material is so popular.
It warps in warm water for gods sake. Summer sun can warp it. And the easy compostability is an urban legend! You need a very special enviroment for that.
Ordinary PETG has *only* advantages over PLA. I switched to it after 300g of PLA which came as bonus with my first Prusa MK2 five years ago and never looked back to that horrific weakass material.
I print pretty much solely in pla. Maybe I’m lazy about getting pet to print properly, because I always have warping, bed adhesion issues, stringing, etc. So unless it’s a part I really need to be strong and very heat resistant (almost nothing I print) I don’t use it. I have pla printed plant pots that have been in Florida sun for over a year. So warping in warm water? I don’t know about that lol. Maybe paper thin prints 🤷♂️
PETG/PCTG have the same heat problems as PLA: it cant go past 80C otherwise it starts to warp (there’s a reason voron parts should be printed in ABS/ASA), Both also tend to shatter/fail without warning (no stress whitening like ABS) among other things they both share.
As for downsides, it needs to be printed slow (prusa limits it at ~7mm3/s), at ABS temps (240C+ hotend /70+C bed) and with minimal part cooling (not good for fast prints, high detail prints, or for most teflon lined hotends) and there’s also the inertness of PET blends making it harder for paint to stick properly (or sand).
it’s not (revolutionarily) better than PLA as much as some think it is (especially with the newer PLA blends around)…
PLA goes soft at 45C already (the often reported 70C for PLA is a lie), 80C is quite a step up.
Still, PLA is used a lot because it’s very easy to print with. It’s very forgiving printing wise. One of the core redeeming qualities is that PLA heated to 200C in a hotend will fuse to cold PLA. With most other plastics this isn’t the case and thus cooling the laid down material too much, or printing too fast will cause failures.
Biggest issue with PLA is that somewhere around 70+C is becomes super sticky if it touches stainless steel. So you do need a teflon lined hotend for it.
PETG is pretty awesome, and there is pretty much no reason to use ABS instead.
(But who am I, as just some random guy on the internet, that made Cura and worked at Ultimaker for 7 years)
This! Thank you for confirming it. I swear I really could squish and bend somewhat thinner PLA nametag/logo in a somewhat uncomfortably warm water.
Regarding reasons for ABS I beg to differ (Yeah, I see the irony for saying similar thing but about PLA). I use ABS:
1. When I want a different failure mode (bending instead of shattering to sharp pieces).
2. When I want to use acetone smoothing.. either due to visual reasons or mechanical reasons (e.g. keycaps/buttons which can be cleaned of grime easily, waterproof parts…).
3. I’ve successfully used ABS as acetone-soluble interface layer on supports for PCTG with Prusa’s MMU2S.
Sorry to be pedantic, but I’m confused
What’s the difference between embedded development and software development. Have I been doing it wrong all these years?
Embedded development refers to programs running on microprocessors embedded in a product. These aren’t “general program” machines, but run only a single fixed set of code.
It’s a subset of software development.
This lamp should be dark on one side,, that’s the best case scenario for full moon!
I wish the thickness increased to the inside of the sphere, so it was smooth on the outside. It looks kind of awful with the LED off.
Cause the moon is perfectly smooth donchaknow
Now, if this had a disc inside that cast a shadow to show the moon phase… that would be outstanding!
So many people are nitpicking here, so I’ll add mine. STLs from Thingiverse aren’t really open source, unless the author includes their CAD files. (Thank you to those who DO share these! )