Hey folks! I am making a few things for my bike this year, and I had some questions about 3d printing since it’s my first time trying out some custom printed parts.
I assume PLA won’t hold up to the heat, but is PETG good enough to hold up?
Also, if I am making an enclosure for a pico or a regular PB, how much airflow should I design around it?
Thanks for any help!
I’d go for PETG if you don’t have an enclosed printer, and ASA if you do.
Mostly I want to keep out playa dust as much as possible, so I’ve fully enclosed them. I also tend to use PBs mostly on things that I’m going to plug in only at night or run off the scheduler, so it’s getting the hottest when the playa is the coolest (nights).
If you’re concerned about heat (I’m sure I’ve probably left one on well into the next day by accident), you could either try to design a snaking ventilation system that might trap (some!) dust, or just leave more air around the thing and design thinner overall walls so that the increased interior enclosure surface area might transmit the heat via conduction more (but I don’t actually know - I’ve never measured such things).
If your enclosure isn’t dust-proof, consider the use of conformal coating on the PCB.
Thanks for the insights 
I have always made wearables and tuck the controllers into a zippered or sewn pocket, but the bike stuff is going to be more exposed.
I have a bamboo labs printer, so I could try ASA, but would need to order some and then configure it. Will give that a go and just prototype with PLA.
Do you usually fully enclose by adding screw points, or using industrial hot glue on one end? I like to keep things accessible in case I need to trouble shoot or want to change components in the future.
Chipping in a few cents:
Second for PETG. It will get more flexible, but hold its basic shape in higher temp. Spring/snap type mechanisms would fail, but a solid box should hold.
I’ve had a bunch of black PETG thin clips installed in my black gutters for 4 years or so now, and the’ve held up in the sun and even when we had that 115° heat wave. They are a little more brittle now, but still holding. I think the black pigment is helping it be resistant to UV. YMMV.
Both the Standard and Pico are rated to operate at up to 85C, but that doesn’t mean you can run them in something that is 85C, so I wouldn’t fully enclose them in something that acts as a good thermal insulator, then stick it in the sun or inside a car. They can tolerate much higher temperature while unpowered.
Airflow helps, but solid materials can work too. You could fill the box with hot glue or epoxy, and the glue/epoxy will transfer the heat to the sides of the case. At night, its not really a problem.
I have a somewhat different way of dealing with the the dust at TTITD. I rarely dustproof anything. I’ve found that the dust doesn’t really damage things until it’s exposed to moisture / high humidity, so I blow everything off with compressed air when I get home and call it good. I’ve had stuff last 10 years using this method. Stuff on a bike will get more abuse though, and if it does rain again…
Most buttons seem to get the worst of it and fail nearly by the end of the week, so going with something waterproof + airtight can save a lot of headaches.
Yeah, I have never had issues during the week except with weak solder points in the past, but this is my first time putting something 3d printed on my bike. I am in the let it breath and then compressed air when I get back camp, but willing to change my ways Maybe I’ll try both approaches and see what holds up.
Anyone have experience with printed TPU in the heat and dust? Does it hold up?
Asking since I haven’t printed with it yet and have been meaning to try it. Would love to use it to create gaskets for some of the enclosures, or even to add to clothing as a cool way to make mounting leds and electronics easier but still conform to movement.
No direct experience but I’ve heard that tpu has very high heat resistance in that it won’t melt until closer to print temperatures. Varies a bit by specific filament. Most seem to be able to handle at least 100c.
A bit late to this… but I have plenty of direct experience.
Ive had prints out of PLA lose their form and start to collapse from being in the direct sunlight (2022 burn which some of you will remember was very hot)
Same burn, a print I made with PETG that was relatively top heavy started to soften just slightly, and at a thin point, it was enough to just slightly lean out of perfect vertical.
I think things you’d want to consider -
with that in mind, either design your prints so it is doing enclosure duty, and has structural support fromm other materials such as bolts or metal inserts.
ASA has a much higher working temp than PETG but its such a pain to print when you need dimensionally stable things (such as enclosures with corners and thin walls). i have basically given up on ABS/ASA for printing boxes/enclosures… the corners just curl and lift too much unless you’ve got a really well heated and enclosed chamber.
what should you use? PA-CF. this stuff is AMAZING. yes - you have to really dry the filament (even if you just pulled it from the sealed bag). you need a hardened nozzle. but once you are set up, the prints come out beautiful, nearly zero warping, and they will withstand the heat.
Agreed about ASA warping (and fume management), but I’ve gotten good results with brims in a heated enclosure (X1C). I like to print the first vertical inch of a part and measure the contraction, then scale the part up in the slicer - I’m usually finding that a scale of 100.2% of original will give me the same final ASA dimensions as PLA.
PA-CF is great (minor VOCs/smell) but at $100/kg vs $32/kg for ASA or PETG-CF, I usually try to use the latter.
@hex337 You asked about TPU as a gasket - it works pretty well. You may wish to turn on ironing for the topside (print on a non-textured PEI plate). Here’s an enclosure I designed for a new art car this year in PETG-CF with a TPU gasket. It held up fine in the sun and light rain, sample size one burn.
It’s the ramp controller for our art car, Mothership.
I really need to spend a weekend with you all 
these are the things I would love to work on and learn!
