Today in Blakeyrat is always several years behind in every tech trend news...
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@Polygeekery I kinda like the idea of using fiberoptics to distribute the light. Fiberoptic bundles for lighting (as opposed to data communication) are cheap ($2.50/foot for a 25 fiber cable from fiberopticproducts.com, probably even cheaper on eBay), and the fibers are much smaller and easier to hide in a tiny model building than LEDs.
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@HardwareGeek said in Today in Blakeyrat is always several years behind in every tech trend news...:
the fibers are much smaller and easier to hide in a tiny model building than LEDs.
You're printing the model, no? Put channels in the bottom of the beams with pockets to hold your LEDs. Your current draw is in the milliamp range so you could in theory use wire gauge in the "human hair" size range. But lacquer coated copper hobby wire would probably be easiest to work with. Or my old standby for cheap small gauge wire, Ethernet cable. But you don't have to strip insulation on the lacquered wire. Solder it as-is and the heat and flux will strip the insulation for you.
But if you just want to use fiber optics, do what you wish. I constantly do things in hobby projects that are in some or many ways not ideal just because I wanted to do it the way I did. Hobbies are meant to be fun, and creative and a method for learning and experimentation. Do what makes you happy.
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@HardwareGeek said in Today in Blakeyrat is always several years behind in every tech trend news...:
But I think that question has been adequately answered at this point.
Have you met me? The mere sight of a puts me in a Wolverine style Berserker rage and I start pummeling it.
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@Polygeekery said in Today in Blakeyrat is always several years behind in every tech trend news...:
If that doesn't make sense
Yeah, it does. The DLP/SLA slicers allow me to rotate and translate arbitrarily, including below the build plate, too, and I remember doing that for one model that I designed with repeated units in the Z direction, originally intended to be printed multiple times with alignment tabs for assembly, and I didn't want the alignment tabs on the bottommost instance that didn't need to align with anything.
non-manifold models
The slicer seems to handle them ok, most of the time, if they're not too badly messed up, but I printed one piece that came out really weird in one area. I'm not going to fix and reprint it though. The 3D prints don't have to be perfect; I can sand and fill like I would a store-bought model or if I were scratchbuilding from polystyrene sheets and strips.
I know you're not doing FDM but download Prusaslicer. There's a ton of ways to split a STL made of multiple distinct bodies but Prusaslicer probably makes it the easiest.
I will be doing at least a little FDM with my son's Ender for some things that are a PITA to assemble from multiple sections. And it's nice to know about some of the better slicer features.
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@Polygeekery said in Today in Blakeyrat is always several years behind in every tech trend news...:
You're printing the model, no? Put channels in the bottom of the beams with pockets to hold your LEDs.
Sure, but even a 3mm LED results in a pretty big beam at 1/87 scale, especially when the beam needs to be printed in telescoping sections because it's too long to print in a single piece. A piece of .75mm fiber is easier to hide than a 3mm LED.
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@HardwareGeek said in Today in Blakeyrat is always several years behind in every tech trend news...:
Sure, but even a 3mm LED results in a pretty big beam at 1/87 scale
Fair enough. Even a 12"x12" beam would scale down to <4mm. Not much margin to work with there for fitting a 3mm LED.
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Dammit, I keep reprinting files I've already printed successfully. Too many twisty little files all alike. I should start deleting them from the USB stick after I print them. Or else print out a BOM and check off each one as I 1) slice and 2) print it. Oh, well; I was thinking of printing two houses, anyway (maybe even a whole neighborhood, but probably not).
I may need to reprint another piece of the roof. The printer doesn't really like supporting a big blob of solid resin from tall, thin supports; it tends to warp the structure, which in this case needs to mate with another section of the roof, but both are a bit warped and do not fit neatly.
And speaking of non-manifold meshes, that other piece of roof was an even bigger blob of solid resin and was even more distorted. I fixed that (somewhat, anyway) last night, but in doing so I created a non-manifold mesh. And trying to fix those problems, the connection between two parts of the mesh was thinner than I realized, and it broke off while I was trying to remove the supports. I was thinking last night that the big blob of solid resin probably should have been printed as a separate piece (which also would have made it a lot easier to hollow into a big not-blob of not-solid resin), but breaking after printing was not quite what I had in mind.
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@Zerosquare said in Today in Blakeyrat is always several years behind in every tech trend news...:
the companies I usually rely on for manufacturing and assembly are in Europe and focus more on "high quality" than "lowest price".
It's very worth going that route, as debugging board faults due to dodgy soldering is very much not fun. The difference between the
worstcheapest and the best is huge.
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@dkf said in Today in Blakeyrat is always several years behind in every tech trend news...:
debugging board faults due to dodgy soldering is very much not fun.
The number of times that I have had weird errors due to not cleaning off flux is sad. I even tell myself everytime, "I really need to stop being lazy and just break out the isopropyl and brush and save myself these issues" but I never follow through with it. I always end up getting careless and lazy again.
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@Polygeekery said in Today in Blakeyrat is always several years behind in every tech trend news...:
The number of times that I have had weird errors due to not cleaning off flux
Indicates you're using too much flux, because you're not hotting up the parts patiently enough.
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@Gribnit said in Today in Blakeyrat is always several years behind in every tech trend news...:
Indicates you're using too much flux, because you're not hotting up the parts patiently enough.
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@dkf said in Today in Blakeyrat is always several years behind in every tech trend news...:
It's very worth going that route, as debugging board faults due to dodgy soldering is very much not fun. The difference between the
worstcheapest and the best is huge.Absolutely. A good part of the circuits I design are custom, (very) low-volume stuff for industrial clients. The money I'd save by using cheap suppliers is not worth the risk (especially the failure happens once it's been installed in production), and some clients would definitely object.
@Polygeekery said in Today in Blakeyrat is always several years behind in every tech trend news...:
The number of times that I have had weird errors due to not cleaning off flux is sad. I even tell myself everytime, "I really need to stop being lazy and just break out the isopropyl and brush and save myself these issues" but I never follow through with it. I always end up getting careless and lazy again.
That's a bit surprising. With some exceptions, for hobby stuff you can usually get away without cleaning the flux, even if it's not a good idea (especially for long-term reliability). Or maybe the flux you use is "special".
@Gribnit said in Today in Blakeyrat is always several years behind in every tech trend news...:
Indicates you're using too much flux, because you're not hotting up the parts patiently enough.
Yeah, no.
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@Zerosquare said in Today in Blakeyrat is always several years behind in every tech trend news...:
Yeah, no.
Have fun with bad solders, then.
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@Zerosquare said in Today in Blakeyrat is always several years behind in every tech trend news...:
That's a bit surprising. With some exceptions, for hobby stuff you can usually get away without cleaning the flux, even if it's not a good idea (especially for long-term reliability). Or maybe the flux you use is "special".
The last time I ran into it was a NodeMCU controller for some WS2812B LEDs. Would that be a special case?
If it makes any difference the perfboard I used for that was branded "Radio Shaek" and smelled like fish oil when I soldered it.
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@Polygeekery said in Today in Blakeyrat is always several years behind in every tech trend news...:
If it makes any difference the perfboard I used for that was branded "Radio Shaek" and smelled like fish oil when I soldered it.
The last time I got some super cheap whatever-grade prototyping stuff (mainly a pile of breadboards and wires), I got a headache of the smell when I first opened up the various containers (apparently the very very cheap plastic softeners they shouldn't use can do that).
Stuff was so cheap they didn't even try to fake a known brand.
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@Polygeekery said in Today in Blakeyrat is always several years behind in every tech trend news...:
The last time I ran into it was a NodeMCU controller for some WS2812B LEDs. Would that be a special case?
Well of course. It's Node, all bets are off
If it makes any difference the perfboard I used for that was branded "Radio Shaek" and smelled like fish oil when I soldered it.
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@Zerosquare said in Today in Blakeyrat is always several years behind in every tech trend news...:
Sorry, I was wrong
It's actually "Radio Shaek 2", so a sequel, which is even worse.
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@Polygeekery said in Today in Blakeyrat is always several years behind in every tech trend news...:
It's actually "Radio Shaek 2", so a sequel, which is even worse.
Radio Shaek 2: Electronic Boogaloo
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There's a meme in the 3D printing subreddits that whenever anyone posts anything even remotely related to food, someone will bring up food safety. Or, more often nowadays, people will post "bUt Is iT fOoD sAfE? /s"
Anyway, someone did an analysis of one of the food safety points (lead in the brass nozzle) and I thought it was pretty entertaining:
So if we make some educated guesses, using the simplest conditions of a 0.4mm nozzle being considered "expended" when it reaches 0.5mm after 20kg of filament, and we anticipate that the high-abrasion path is roughly 1mm long with a highly leaded (3.5%) brass, I get:
0.07mm3 material or 0.0024mm3 of lead, which is 2.4x10-6 cc. Now, at 11.6g/cc, that is 27μg of lead distributed over 20kg - which I'm going to take as uniform for simplicity - or approximately 69ng of lead in a 50g cookie cutter (or krispy form).
From a random google search, "The Centers for Disease Control (US) has set the upper limit for blood lead for adults at 10 µg/dl (10 µg/100 g) and for children at 5 µg/dl" and the average 80lb child will have around 27dl of blood (per Google, of course) so we can set an upper limit of only 135μg in a child's blood.
Conservatively assuming 100% absorption, and based on these numbers, I recommend that no child eat more than 2000 entire cookie cutters. That includes their entire childhood consumption of cookie cutters. Spanning from age 4 until age 18, That's no more than 140 cookie cutters per year or one entire cookie cutter every three days.
I hope that you find this analysis useful, and remember to hit that like button and follow me for more riveting future content.
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@hungrier I know some people who work with food safety, specifically stuff touching food. What they look at is migrations from e.g. packaging (and, specifically ink, if the packaging is printed) that touches the food. I'd have to ask what (if anything) regarding manufacture needs to be disclosed.
I'd be more worried about whatever you're printing in. Something like pure PLA probably wouldn't even be that bad (up to certain temperatures). Question is what else is in there in terms of softeners/hardeners/dye/special sauce/glitter/bacon/etc etc.
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@cvi My understanding is that PLA by itself is fine, but some additives, colours, specially formulated versions, etc may not be. I think PETG is similar. There are also certified food safe materials available.
The biggest food safety concern, at least for FDM printed items, would be bacteria collecting in the hard to clean micro gaps between lines and layers
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Status: Experimenting with DIY solutions for desiccant packets. I got some silica cat litter, and so far the material properties are looking quite promising: It can absorb a shitload of liquid water, and can be reactivated using the microwave. However, I haven't yet determined if it can absorb that much from the atmosphere, and if coffee filters are a suitable material for the pouch or I would need to find something else
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@hungrier said in Today in Blakeyrat is always several years behind in every tech trend news...:
However, I haven't yet determined if it can absorb that much from the atmosphere, and if coffee filters are a suitable material for the pouch or I would need to find something else
A steam test could answer both questions. But rates are an issue, it's still saturated. Getting controlled humidity air is, hard to do at home.
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@Gribnit said in Today in Blakeyrat is always several years behind in every tech trend news...:
A steam test could answer both questions.
I'm doing a closer to real world use test, which is to leave the pouches in a sealed bag with a hygrometer and periodically note the reading. So far, one pouch left overnight didn't do all that well
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@hungrier said in Today in Blakeyrat is always several years behind in every tech trend news...:
I'm doing a closer to real world use test, which is to leave the pouches in a sealed bag with a hygrometer and periodically note the reading. So far, one pouch left overnight didn't do all that well
At gaining weight, or reducing ambient humidity? Absorption rate is probably delta-driven.
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@hungrier said in Today in Blakeyrat is always several years behind in every tech trend news...:
silica cat litter
@hungrier said in Today in Blakeyrat is always several years behind in every tech trend news...:
didn't do all that well
Is it difficult to get plain silica gel where you are? Google gave me 600+ results from just Amazon, not to mention other sources. I'm sure there must be a bunch on eBay, too, but I didn't bother scrolling that far. Surely there must be someone who'd ship to wherever you are, if you can't get it locally.
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@Gribnit said in Today in Blakeyrat is always several years behind in every tech trend news...:
At gaining weight, or reducing ambient humidity? Absorption rate is probably delta-driven.
At reducing humidity inside the bag. I'm assuming straight out of the package, the stuff is relatively unsaturated and should have the best chance to absorb as much as possible, although that may not be a good assumption. I haven't tried it yet with my soaked then dried pouch.
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@HardwareGeek said in Today in Blakeyrat is always several years behind in every tech trend news...:
Is it difficult to get plain silica gel where you are?
Locally, I haven't been able to find it aside from commercial desiccant packets. Online, I can get jugs full of them, even indicating ones, but they're horribly expensive: $34.99 for 2 lb, $69.99 for 8 lb, that sort of thing. And of course the packets but those are even more expensive. Silica cat litter is about $2/lb. If it works, I've already bought enough to last a lifetime (unless I get a cat)
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@hungrier What about those dehumidifier packs? They can get moisture out of the air, and Amazon had some at about €15 for 10 packs with 500ml of absorbed water each (according to the posting, so adjust for reality as usually). Total weight including packaging is 3kg, so I'd guess somewhere around 2kg of actual stuff.
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@cvi I haven't seen anything like that. There are some calcium chloride dehumidifer refills, but All the ones under $20 are half a kg or less
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@hungrier said in Today in Blakeyrat is always several years behind in every tech trend news...:
@cvi I haven't seen anything like that. There are some calcium chloride dehumidifer refills, but All the ones under $20 are half a kg or less
Depending on the application, this might be a drop in the bucket or a 5-year supply.
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I mentioned in, I think, the analog hobbies thread that I was printing a couple of buildings for a model railroad layout, one of which is a house made up of lots of little fiddly bits to be painted and assembled (much like an injection molded polystyrene kit you might buy at a hobby shop). There was one part (a fairly substantial beam, well, substantial for that tiny scale) that I could have sworn I had printed, but I couldn't find it when I was looking for it yesterday or the day before. Huh, I thought I printed it, but I guess not.
I found it today. In the wash bath. It had been soaking in alcohol for probably at least 3 or 4 days. I had looked in there, sort of, but I didn't see it. The alcohol is sufficiently cloudy from dissolved resin residue that I didn't see the gray pieces of plastic in the bottom of the cloudy, gray alcohol, and I didn't open the container to pull out the wash basket, because when I was looking for it I didn't want to have to put on gloves to handle not-fully-cured resin residue.
Oh well, I found it, and the extended wash doesn't seem to have harmed it.
Meanwhile, further printing is awaiting assembly of the stuff I've already printed, so I can figure out which of the almost 50 separate STL files I've printed and which I haven't. (I've printed all the major components; it's the little fiddly bits like doors and windows and door frames and window frames and so on that I've kinda lost track of.) Assembly is awaiting painting of the parts before assembly, and painting is awaiting arrival of a compressor for my airbrush, which should happen Wednesday, Delivery Distortion Field permitting, and paints, which are also scheduled to arrive Wednesday, but they haven't shipped yet.
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@HardwareGeek said in Today in Blakeyrat is always several years behind in every tech trend news...:
the extended wash doesn't seem to have harmed it.
It does seem a little more flexible than I would expect for that type of resin, even post-cure, but that shouldn't be a problem. It's not like it has to support the weight of a real roof.
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@HardwareGeek said in Today in Blakeyrat is always several years behind in every tech trend news...:
@HardwareGeek said in Today in Blakeyrat is always several years behind in every tech trend news...:
the extended wash doesn't seem to have harmed it.
It does seem a little more flexible than I would expect for that type of resin, even post-cure, but that shouldn't be a problem. It's not like it has to support the weight of a real roof.
As as long as you don't print any tiny people to live in it, this seems fine.
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@hungrier said in Today in Blakeyrat is always several years behind in every tech trend news...:
I haven't seen anything like that. There are some calcium chloride dehumidifer refills, but All the ones under $20 are half a kg or less
Something like this:
https://www.amazon.co.uk/ANSIO-Dehumidifier-Condensation-Moisture-Dehumidifiers/dp/B015AOGP1S/ref=sr_1_4?crid=2P8N8VKE9IFTK&dchild=1&keywords=dehumidifiers&qid=1629235782&sprefix=dehumidifi%2Caps%2C225&sr=8-4(Fuck, Amazon links are terrible.)
FWIW- didn't find anything on the .de version; didn't check .com. Not sure what the shipping conditions are. I think .com ships out of the US to Europe (tend to avoid doing that though), not sure about the reverse. For something that's €15, the shipping costs might get somewhat prohibitive.
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@cvi Nothing like that on .ca. Instead I've got listings like
- 6 pack of 230 g each, $32.99, and the unscented version isn't even available
- 30 pack of 260 g each, $95.97
+$12.48 import fee
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Update: I've done some (sloppy) science and determined a few things:
- out of the box, the silica cat litter that I bought is no good for absorbing moisture from the air. In fact it increases humidity in an enclosed space
- however, after cooking the moisture out of it, it works amazingly well when placed in a dry box. ~50% humidity, down to under 20% in like 15 minutes, using a fairly small amount of it
- similarly, it seems to work pretty well, although not as fast, when placing coffee filter pouches of the dried crystals in a sealed bag
- zip ties work way better and 1000x faster and easier for closing the pouches than tying fiddly knots in fishing line
So now I can use this stuff along with/instead of normal silica gel packets to keep my various filaments dry
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@Dragoon In my home it's around 45%. Don't know about outside but there's supposed to be a bunch of rain later today
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@hungrier 80°F (or 82, depending on which source of weather info you look at); headed for a forecast high of 89. Humidity 92%. Ugh. Not much better inside.
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I also just realized that I'll almost certainly reprint a fairly large component for my dry box, and will likely have to print some extra shit to extract the bearings out of the original one
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@hungrier said in Today in Blakeyrat is always several years behind in every tech trend news...:
I also just realized that I'll almost certainly reprint a fairly large component for my dry box, and will likely have to print some extra shit to extract the bearings out of the original one
Did the printer come with plans to print all its parts?
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@HardwareGeek said in Today in Blakeyrat is always several years behind in every tech trend news...:
Humidity 92%.
That sounds normal. (Though your temps are higher than here.)
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@dkf It is normal for morning, when the temperature is low. Right now, 15:20-ish, the temperature is up to 90, 91, or 92°F (33-ish°C), depending on the source of the info, and the humidity has dropped to 59%.
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@HardwareGeek said in Today in Blakeyrat is always several years behind in every tech trend news...:
@dkf It is normal for morning, when the temperature is low. Right now, 15:20-ish, the temperature is up to 90, 91, or 92°F (33-ish°C), depending on the source of the info, and the humidity has dropped to 59%.
Still sounds rather... swampy. Not that that's a bad thing. How did you avoid civilization in a drainage basin like that?
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@Polygeekery (or anyone else with resin printing experience), do you have experience with different brands of resin? I need to get more black resin, and I'm not entirely happy with the Anycubic black. It's more of a dark-tinted transparent/translucent, and I'm looking for a really opaque black.
Formlabs has one that claims to be opaque, but it's almost 3x! the price of the Anycubic. So does Monocure3D, and it's nearly as expensive.
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@HardwareGeek said in Today in Blakeyrat is always several years behind in every tech trend news...:
I need to get more black resin, and I'm not entirely happy with the Anycubic black. It's more of a dark-tinted transparent/translucent, and I'm looking for a really opaque black.
Those sound pretty good. Any word on the flavor profile?
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@HardwareGeek the problem with opaqueness is that it can make it impossible to get a good post-cure as UV cannot penetrate it. That can leave the center "gummy". I wonder what the other brands are doing to solve that issue?
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@Polygeekery said in Today in Blakeyrat is always several years behind in every tech trend news...:
@HardwareGeek the problem with opaqueness is that it can make it impossible to get a good post-cure as UV cannot penetrate it. That can leave the center "gummy". I wonder what the other brands are doing to solve that issue?
Selective permissivity to UV would be a good angle.