I’m in the process of replacing all my single-color christmas lights with addressable RGB LEDs, but the 12mm “bullet” form factor of them is different from the traditional incandescent mini lights, the 5mm wide angle LEDs, etc.:
You’d think they’d make C6/7/9 bulb covers that attach to them, but I have yet to find any for sale, anywhere. As such, I want to 3D print some, along with 12mm bullet pixel-sized replacements for my snowflake lights:
What’s some good filament I can get that will be reasonably clear and stay that way (without yellowing or getting too brittle) for several years’ worth of Christmas seasons, despite UV/rain/cold exposure?
(Bonus question: anybody know a good way to model the facets in those “strawberry” lights? The C7 bulbs on Thingiverse, such as this one, are all smooth, LOL.)
Edit: by the way, to be clear (pun intended): I don’t need optical clarity like the lens guy; scattering the light is fine. (In fact, doing that on purpose is kind of the point of modeling a faceted C7 bulb instead of a smooth one.) I just want to make sure that whatever part of the filament that doesn’t manage to be transparent is white, not tinted some dingy color.
I do happen to have some Inland “natural” PLA laying around and did a test print in that. It’s not too bad – only a little bit yellow at the wall thickness I’m using – but I fear for how it will hold up over time.
You must log in or # to comment.
Honestly? This seems like a really bad use case for FDM (less familiar with resin). Clear filament is very deceptive and actually getting reasonably translucent prints out of them can be a hassle. CNC Kitchen did a video on this a few years back. Far from perfect but https://www.youtube.com/watch?v=9qb25Gi4Jv0. Of particular note is the cooling and support related hassle which is of particular interest if you are printing light bulbs.
I get you don’t care if it is clear. But clear filament gets REAL cloudy REAL fast and that is a factor with lighting.
Also? You already keyed in that UV and exposure are hell. Also understand that even LED bulbs can get pretty hot. Not hot enough to melt the plastic (probably) but likely enough to cause further clouding and so forth.
People very much underestimate just what a torture test xmas lighting is and why so many are designed to be more or less consumable objects. You can stretch that out if you properly maintain them in the off months but you are still expecting them to run for 8-12 hours a night for a month (or more) straight during some REALLY harsh weather.
I would also make sure the prints are actually water tight. Because properly wired lights are fine if a diode shorts out. How much do you trust your wiring for something that lives on the exterior of your home in the rain and snow? Hell, I barely even trust commercial xmas lights for that purpose.
deleted by creator
I would just run clear PETG to see how it does, and keep the model files on hand in case they need to be replaced. PETG/s UV resistance is decent and will certainly last at least a continuous year or two in most exposure situations, and it is by far the most cost effective and easiest to print; it’s cost effective enough that even if they begin to fail after 2 years, you can print more. and at <$20/kg, it’s the cheapest to experiment with.
Polycarb will be more UV,thermal, and impact resistant but not sure it’s worth the added cost and printing difficulty for this kind of project. The one major benefit it would have is higher light transmittal vs clear PETG, but it’s really not by much, and probably not worth the $15+/kg premium over PETG.
Any opinion on specifically which clear PETG I should get?
- Overture ($14.39/kg)
- Creality ($14.39/kg)
- “3DHoJor” (whatever TF that means) ($10.92/kg) – note: this one is “natural,” not “transparent”-but it’s cheap!
- Inland (pretty sure it’s $14.99/kg in-store right now, despite what the website says)
Overture. IDK where Creality gets their filament but I guarantee they don’t make it themselves and printers are their business, not filament.
Never had Overture steer me wrong. I use Overture almost exclusively for ASA and they’re reliable, don’t see any reason why they wouldn’t work for PETG too.
Their cardboard spools aren’t Bambu AMS compatible (or compatible with any filament solution that relies on spool edge rollers), so keep that in mind.Inland is Microcenter’s in home brand and I’ve heard good things about them too.
or compatible with any filament solution that relies on spool edge rollers
?
I’ve run Overture cardboard spools in my Sunlu filament dryer directly into my printer many times with no incident. It has rollers for the spool edges, no center axle. And other brands’ cardboard spools as well.
Ah. Well bambu ams has issues with their rollers slipping on cardboard spools unless you print a clip on ring that covers the outer edges, only because bambu uses the rollers to backdrive the spool when unloading. Not so for basic feeders
Is there any reason to think Creality would be a particularly good choice because it matches the brand of my printer? (If not, I’ll get the Overture.)
Not really any correlation. Plastic filament is plastic filament. About the only outlier would be Bambu with their rfid AMS identification system. But even then, I’ve put 5 different brands through my Bambu printer and honestly, Bambu filament has performed the worst lol (it’s more wet than most out of the box and needs drying).
This sounds like something Alec of Technology Connection would ask.
Hmmm…
I’m flattered, but that guy is into faithfully mimicking incandescent Christmas lights, not programming them to flash different colors to music.
Yet…
I printed some PETG clips for my outside railing to attach chicken wire (part of a catio). They’ve been fully exposed to the elements and sun for 2 years now, and aren’t brittle yet.
Hmmm, I would usually go for ASA for anything outside, but searching around for transparent ASA comes up empty… I guess maybe transparent ASA isn’t a thing? Too bad, since you could smooth it with acetone to make it even lower opacity. You could also look at Polycarbonate and PETG, which I know can be made transparent, but those might yellow a bit after a few years.
I’m interested in other people’s thoughts. Definitely a good question!
Agree, Asa ideal, but I’ve never seen it in transparent varieties. I’d actually try PVB - probably some of the nicest transparency. Might not hold up well outdoors, but I’d give it a shot and then go to PETG if it falls apart.
PVB filament is giving me sticker shock ($36 for 750g), as is polycarbonate ($30 for 1kg).
I think PETG is probably the way to go. Anybody have strong opinions between
- Overture ($14.39/kg)
- Creality ($14.39/kg)
- “3DHoJor” (whatever TF that means) ($10.92/kg)
- Inland (pretty sure it’s $14.99/kg in-store right now, despite what the website says)
?
Inland is my go-to since Microcenter contracts with good manufacturers. Their ASA is made by Polymaker, the PLA+ is eSun (I use a lot of it), but I’m not sure who makes their PETG. I’m sure it’s good though.
I’ve tried Overture, Creality, and Inland (all black though, not transparent) and Overture printed the best for me (at least for functional parts where I cared about print quality and tolerances). Inland’s PETG+ and High Speed PETG was even better though.
Oh, another thought - you could use a UV blocking clear coat such as this on your print. I still would avoid PLA though, since it might get hot in the sun. It would be important to get a complete coat with that spray, even between layer lines. You might want to think about using a clear resin if you have access to a resin printer, since it would have a much smoother finish before being coated.
Yeah, I’ll probably do a clear coat.
The thought of using a resin printer had crossed my mind, as well. It wouldn’t work for the snowflakes – those would be too large for any but the most gigantic resin printers – but it would be optimal for the C7 bulbs. That said, I literally just bought a new filament printer (just an Ender 3, not a fancy Bambu or anything – until now I was making do with a MP Mini!) and buying two printers at the same time makes my bank account sad.
Also, I’m not sure the material resin printers use is all that great at resisting UV either.
Oh 3d printer resin is absolutely not UV resistant - resin printers use UV light to solidify the resin at each layer, and exposing a print to too much UV light after printing can cause UV burn, similar to a thermoplastic.
Coating the print in a UV resist clear coat should prevent UV light from reaching the print itself, and preventing the burn; think of it as sunscreen for your print 😉
PETG is probably the way to go.
Honestly PLA would probably work just fine for this application as well. It’s not like the things are going to be enduring any mechanical load or high temperatures.
It’s really the UV I’m worried about. Even my commercially-made snowflake lights are pretty yellowed and brittle now, and I think they’re still less than a decade old (so less than 10 months of actual use).
That should tell you exactly why worrying about UV is a mug’s game. This is going to be an issue with all polymers, even tough old polycarbonate.
You could probably improve matters by clearcoating your objects after printing. The stuff used on car headlights after polishing is specifically for this purpose, and I believe Krylon makes an “arts and crafts” oriented clear coat that’s also billed specifically as UV protective and is probably cheaper.
That is a very good point!
deleted by creator
Well, the difference here is that if they yellow out in 3 years, you can simply print replacements for a few bucks instead of junking the string.
