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Cake day: June 12th, 2023

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  • The right flowrate for dimensional accuracy is likely not the right flowrate to end up with solid parts where internal lines are properly smushed together. The sides of a 3D printed object aren’t flat, so if you adjust the flow rate so that the bits that stick out the most are exactly where you asked the slicer to put the edges of the wall, you end up with your internal lines just barely touching each other instead of properly bonded. You want to tune your flow rate to get solid parts when you ask for them, set the line width a little wider than your nozzle to give space for material to flow outwards (which happens whether or not you want it to, but things work better if you tell the slicer it’s going to happen), and then when you’ve got a part that really needs the dimensional accuracy to be right, maybe temporarily use Orca Slicer instead to get its precise wall feature.




  • The DHT11 has been replaced twice with similarly-priced but more accurate models, first the DHT22 and then the AHT20. In my experience, the AHT20 is a lot better than the DHT22, mainly because its power consumption is far lower, so it doesn’t mess up its readings by getting hot.

    Also, at that size, I’d be very surprised if the dehumidifier has a compressor. It’s much more likely that it’s got a Peltier plate, and they’re not very good. They use a lot of power to develop and maintain a fairly small temperature difference, so if they’re in a confined space, they heat up the air quite a bit, and then the water from their tank will more easily evaporate.

    If you’re willing to spend some money, a solid state ion membrane dehumidifier might be better for a small cabinet than a compressor-based one, as it’ll be easy to ensure the water goes out of the cabinet instead of into a container that can’t be emptied without opening the cabinet and letting more humidity in. They’re definitely not cheap, though. I think they’re still under patent as there’s only one manufacturer that I can find, so maybe they’re the dehumidifier of the future even if they’re not suitable right now.


  • If it’s the problem that I’ve seen people complain about in the past, it’s effectively the same as HTTPS ‘not supporting’ end to end encryption because it runs over IP and IP packets contain the IP address of where they need to go, so someone can see that two IP addresses are communicating, which is unavoidable as otherwise there’s nothing to say where the data needs to go, so no way for it to get there. Someone did a blog post a couple of years ago claiming Matrix was unsecure as encrypted messages had their destination homeserver in plaintext, but that doesn’t carry any information that isn’t implied by the fact that the message is being sent to that homeserver’s IP.



  • When it’s hot, it stinks of hot ABS, and it dissolves in acetone. I’ve read that sometimes budget filament manufacturers will use the same pigment across their whole material range, even if it’s not capable of withstanding the print temperatures of some of them, but it’s ABS+ rather than pure ABS, so it could be full of mystery additives that don’t handle heat well, too.

    There’s not much point using it as glue as I’m not going to get through a whole kilo worth of ABS glue, and produce more than enough ABS scraps from test prints and support to always make a colour-matched glue anyway.



  • Fillets are easier to print horizontally than chamfers as they spread the acceleration (i.e. the thing that makes sharp corners bad) over the while fillet instead of just splitting it into two stages like a chamfer would.

    Chamfers are easier to print vertically than fillets as the overhang is limited and consistent.

    There’s no overhang for a horizontal corner as you’re printing the same shape onto the layer below, and no acceleration for a vertical corner as it’s entirely separate layers so the toolhead never has to follow the path of the corner.

    It sounds like you’ve read (or only remembered) half a rule. It’s not the case that either half of the rule is used the majority of the time because 3D printers are used to print 3D objects, so they always produce objects with both horizontal and vertical edges.


  • I’ve never actually needed primer to paint PLA unless the paint I was using was terrible, and wouldn’t have stuck to the primer very well, either. Tamiya’s acrylics have been entirely issue-free for me, both with a brush, or thinned and airbrushed, and they’re not that expensive, but I’ve also had acceptable results with random fifteen-year-old tubes of really cheap acrylics that were sold more as a children’s toy than a serious paint (although a lot of these tubes had gone bad in that time) and with Humbrol and Revel acrylics and enamels (although their acrylics come in pots that don’t seal very well, so it’s not that uncommon for them to be already cured when you first open them - if you’re buying liquid acrylics for model painting, Tamiya is a better choice).


  • Enzymes are specific to a particular molecule, or class of molecules with a particular pattern. A PEI buildplate is not getting eaten by the proteases in a dishwasher tablet. The reasons you’re not supposed to rinse things before putting them in the dishwasher are:

    • most dishwashers have sensors to detect how much material is ending up in the water, and if things have been rinsed, it can mislead them into thinking the load is lighter than it really is.
    • dishwashers replace some of the dirty water part way through the load, and the enzymes are more soluble than the dirt, so if there’s not much food residue for them to stick to, they can end up getting rinsed away part way through the cycle.
    • it uses water and your time to rinse the dishes first, which is a waste if it doesn’t make them end up any cleaner.

  • AnyOldName3@lemmy.worldto3DPrinting@lemmy.worldResin printing in the cold
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    3 months ago

    I think it was pretty reasonable of them to worry - lots of people who don’t like spending unnecessary money also don’t like spending not-obviously-necessary money on safety equipment, and there’s plenty of material on the internet that would imply resin printing is completely safe as long as you don’t drink the stuff. Resin printing with woefully inadequate ventilation/PPE is really common, so it’s a pretty safe bet that anyone asking questions is probably also doing something unsafe without realising it, especially as resin not liking the cold is something a lot of people learn about fairly early on (unless they live somewhere where it never gets below 20°C).