Post AhziKzB6D2ZSINoLEe by darkling@mstdn.social
(DIR) More posts by darkling@mstdn.social
(DIR) Post #Ahzeyp2Kvz2gbqS6m8 by foone@digipres.club
2024-05-17T20:37:32Z
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Here's something cool I never realized existed:PCBs distributed through magazines! From Radio Electronics (June 1987):https://archive.org/details/radio_electronics_1987-06/page/n68/
(DIR) Post #AhzfD8vHnJ2KL7z14S by slaeshjag@bitbang.social
2024-05-17T20:40:59Z
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@foone I got one with a computer magazine in 2005, with an article on how to assemble it and a long, long listing of PIC assembler to make it do stuff
(DIR) Post #AhzfUGwPEixE88fuG8 by foone@digipres.club
2024-05-17T20:42:25Z
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The way this works: You have a blank PCB coated in a thin copper layer, and it's coated in a photoresist material. This material breaks down when exposed to light.You then shine a bright (usually UV) light at it for a while, and the spots which got hit by light break down, while the other parts (which were in shadow) remain on the board.You then use a corrosive chemical to etch away the copper layer, but it only etches away the parts that aren't covered in photoresist.
(DIR) Post #AhzfgYZNWHIkHNlH9s by darkling@mstdn.social
2024-05-17T20:42:50Z
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@foone Like code listings, for the hardware types.How would you transfer it to the board? Photocopy onto (several(*)) acetates, expose the photoresist and then etch?(*) For the density of the black.
(DIR) Post #Ahzg1KmLzKzHabjpCa by foone@digipres.club
2024-05-17T20:43:15Z
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So by using these magazine pages as your mask, you can create these PCBs with a chemical developing process and some blank copper-coated PCBs. That's really cool!
(DIR) Post #Ahzg1O9VRiI23HarCq by foone@digipres.club
2024-05-17T20:44:31Z
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Normally you'd do this by printing or photocopying onto transparent paper, but I think they're saying you can just turn up your brightness/wait longer and blast the light straight through the paper.I wonder how well that worked?
(DIR) Post #Ahzg1PmtMlOB7j1pEe by foone@digipres.club
2024-05-17T20:46:46Z
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And of course on one of the following pages, they had ads from companies who were happy to sell you the chemicals and equipment needed to make circuits this way.
(DIR) Post #AhzgI4o0d74ayKUntQ by Xilokar@mamot.fr
2024-05-17T20:44:09Z
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@foone PCb fits on a single page of the magazine !I remember lines/pages of code to be typed from a magazine...
(DIR) Post #AhzhkQe77Zlglsx0Do by slaeshjag@bitbang.social
2024-05-17T20:46:55Z
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@foone oh right, you mean just the patterns to make one. Some magazines even included a ready-to-solder PCB
(DIR) Post #Ahzi2aaqsMCypq5ISu by tehstu@hachyderm.io
2024-05-17T20:47:19Z
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@foone I vaguely recall doing this in school in the early 90s. You create the circuit on a transparent sheet, building it out of little black lines, circles for pads etc. Maybe they were stickers? I dunno. Anyway, somehow you put it on the board and shine light through it, them put the board in a vat of corrosive stuff which etched away leaving the desired circuit. Wowsers, I haven't thought of that in decades.
(DIR) Post #AhziEi88gC49gYQz7A by tayledras@mastodon.social
2024-05-17T20:47:37Z
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@foone And NOW I really need to read up on how EPROMs allow reuse through erasure and reprogramming via UV light.I used EPROM burners back in high school and college, but didn't really take the time to learn how reuse was possible.
(DIR) Post #AhziKx3a61MviUHJEu by darkling@mstdn.social
2024-05-17T20:48:21Z
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@foone I think I met something like this back in 1989 or 1990. A friend's dad was doing this with his own designs. He found that photocopies or laser prints on acetate weren't dense enough to block the UV properly, so you had to run it through the printer several times to get the ink density to make it work.
(DIR) Post #AhziKzB6D2ZSINoLEe by darkling@mstdn.social
2024-05-17T20:51:34Z
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@foone He also had problems with drilling the holes in the board, so he was building an X-Y rig for a drill.We spent a long night with an Acorn A440, me on the front end with the keyboard, him on the back end with the printer port and an oscilloscope, working out how to write a driver for this thing that ran off the !Draw files he'd use for the board designs, and would put the holes in the right place.
(DIR) Post #AhziTGQPy8dk6RvJpo by foone@digipres.club
2024-05-17T20:48:56Z
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The cool thing about this kind of photoresist PCB etching that may seem surprising if you know how circuit boards are designed today... you could totally do this without a computer. Fundamentally you just need to come up with a photomask: that's some dark black ink on a transparency. You could use stencils and stickers and markers to make that, then turn it into a PCB. The only electronics you need is a bright light.
(DIR) Post #AhziTJDPax1EkyrTTk by foone@digipres.club
2024-05-17T20:50:17Z
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it's just neat to think that today PCB design is "you use this complicated program on a computer then send some files to a place that mails you back a bunch of PCBs", when 30 years ago it would be more "you carefully do some arts & crafts with stickers and then some chemical processes"
(DIR) Post #AhziTKSgxcpscf1Bw0 by foone@digipres.club
2024-05-17T20:50:49Z
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It's similar to how "amateur photography" went from "you have a dark room and a bunch of chemicals" to "you have a phone in your pocket"
(DIR) Post #Ahzildg4FuvrQp0OrQ by jordan@sometimes.social
2024-05-17T20:50:20Z
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@foone full-size expansion card on a centerfold
(DIR) Post #AhzjQKUcULthnw3NnU by vxo@digipres.club
2024-05-17T20:51:31Z
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@foone strange bubbling potion!!!
(DIR) Post #Ahzjj3I0fselx25CpU by djsundog@toot-lab.reclaim.technology
2024-05-17T20:52:04Z
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@foone suddenly realizing that this is only a robot arm away from making an SLA 3d printer into a board etching machine. nifty - thanks!
(DIR) Post #Ahzk28mkSvA8UwYxU0 by drewfitz@mastodon.social
2024-05-17T20:52:01Z
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@foone oooo did they have two side patterns or was that before the general use of double layer boards?
(DIR) Post #Ahzk9mSFNGPDYccHKq by foone@digipres.club
2024-05-17T20:51:58Z
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@jordan I think that's a futurama joke.but yeah, I love the idea
(DIR) Post #AhzkJP0DQJi5iZ5p1k by vxo@digipres.club
2024-05-17T20:53:13Z
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@foone you have me tempted to merge graffiti art techniques into freehand PCB pieces, develop, then sneak in circuitry!
(DIR) Post #AhzkYSBpr4NRwmhmAi by foone@digipres.club
2024-05-17T20:53:31Z
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@drewfitz yeah, this design here is a two-layer one! I'm not sure how you do that. I guess you just expose it twice, once on each side, and then do the etch step once?
(DIR) Post #AhzkvaPvQrho7kKHDs by foone@digipres.club
2024-05-17T20:55:41Z
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@Sentry23 the magazine suggests using mineral oil for that purpose!
(DIR) Post #AhzlG527JQrorxxi4W by foone@digipres.club
2024-05-17T20:56:30Z
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@darkling yeah the vias are real tiny, so you need a fast drill with a very tiny bit, so it's a little tricky to do by hand.
(DIR) Post #Ahzlreqf7C9KfAWShc by deadguy@rebel.ar
2024-05-17T20:58:32Z
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@foone that's awesome. These days you can use glossy magazine paper, a laser printer, and a clothes iron
(DIR) Post #Ahzm2ibTUhbtUih1Gq by foone@digipres.club
2024-05-17T20:58:58Z
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@MonniauxD Transparency slides seem to be the usual way to do this, but I guess you can use white paper if the light is bright enough and the ink is dark enough
(DIR) Post #AhzmnjECzO2d2hE6D2 by masterzen@hachyderm.io
2024-05-17T21:01:21Z
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@foone Oh, yes I was doing that when I was a teenager with my dad in the 80s. The difficult part once etched was drilling the holes for the components. That was very tedious. You could also purchase "décalcomanies" (sorry can't find an English word) of pads and tracks that you could transfer to the copper layer. It's now so much easier to produce Gerber files and have the pcb manufactured II :)
(DIR) Post #AhzmwG5IiKErGG7xGi by keisisqrl@mastodon.eternalaugust.com
2024-05-17T21:01:41Z
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@foone if you print on thin printer paper it's transparent *enough* to UV to expose chemicals sensitive to actinic light, and toner is plenty opaque. Exposure might be more finicky because of lower contrast, and it probably wouldn't work at all with a dye-based inkjet printer.
(DIR) Post #AhzmwHRJfxRXSpR3Ds by keisisqrl@mastodon.eternalaugust.com
2024-05-17T21:05:04Z
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@foone it turns out the gold standard for photo printing, Epson pigment inkjets, are also perfect for UV processes (including photogravure, basically this exact process) when printed on transparency
(DIR) Post #AhznAW5C1tPSvusLpY by Jencen@furry.engineer
2024-05-17T21:02:02Z
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@foone Huh.... I wonder if that'd work with the PCB layouts that are in older service manuals from places like Yamaha or Roland >.>
(DIR) Post #AhznJvLfSfzptq4Ewy by keisisqrl@mastodon.eternalaugust.com
2024-05-17T21:02:38Z
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@foone you could do it with a pigment marker! But there are also resist pens you can just draw on a copper-clad plate with.
(DIR) Post #AhznRZvB0m2hlEKI6a by foone@digipres.club
2024-05-17T21:03:16Z
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@Jencen certainly. Especially if you scan them, clean them up a bit, and print them out onto transparent sheets
(DIR) Post #Ahznrz6nzH1NPLMC0G by gsuberland@chaos.social
2024-05-17T21:06:30Z
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@foone iirc one of the tricks was to add some sort of clear oil (like baby oil) to stick it to the PCB, which made the white paper go kinda clear.the actual home etching process is super messy though. ferric chloride stains eeeeeverything, it's bad for your skin, and you have to neutralise it before disposal which also creates a lot of mess. I used to own a kit and used it only a couple of times because the cleanup is horrible.
(DIR) Post #Ahzns2BAZVIKvkQDiq by gsuberland@chaos.social
2024-05-17T21:11:41Z
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@foone although you can buy PCB etching tanks where you put the boards in a little carrier thing vertically (helps make the etch a bit more consistent) and some of them come with two separate compartments so you can have one with the ferric chloride and the other with water, and that makes things a lot less messy, since the ferric chloride is far less likely to splash and you're only moving the board a few centimeters to get it into the water tank.
(DIR) Post #Ahzo0Du2rnRRbkJiYi by cadey@pony.social
2024-05-17T21:07:42Z
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@foone what would you call this
(DIR) Post #AhzoASyFhR73EgAXmC by _thegeoff@mastodon.social
2024-05-17T21:07:19Z
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@foone Hmmm...cyanotype PCB?
(DIR) Post #AhzoLpKwspZXmwCbtQ by ComradeGibbon@mastodon.social
2024-05-17T21:11:25Z
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@foone Company I worked for in the 80's the draftsman laid out PCB''s at 4X scale using tape and stickers on acetate film.Also old etching process you hope it only etches the exposed copper. I swear that's why early PCB's had snaky traces instead of sharp corners.
(DIR) Post #AhzoVD0WFL2po77Vqq by chfour@wetdry.world
2024-05-17T21:10:26Z
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@foone you could also probably do thermal transfer with an iron
(DIR) Post #AhzoaRo0ed9D9QlbyS by wollman@mastodon.social
2024-05-17T21:12:28Z
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@foone See, I know nothing about the modern process (I knew I wasn't going to be a Hardware Person 30 years ago) but was passably familiar with the traditional process thanks to magazine articles...
(DIR) Post #Ahzohh2OQ8ROQ3wwEK by moemoe@chaos.social
2024-05-17T21:12:54Z
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@foone As a kid I always went to the local library and read Elektor, they also had tons of Designs and PCBs to copy and etch using toner transfer: https://archive.org/details/ElektorMagazine/Elektor%5Bnonlinear.ir%5D%201974-12/
(DIR) Post #Ahzoo5DPRQY78u9KNc by homelessjun@mas.to
2024-05-17T21:11:47Z
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@foone pcb images printed in magazines often were printed in reverse so that they could be xerox-copied on to polyester film, which it barely stuck to, then the print flipped onto the copper board and toner transferred using a hot iron. then tape was used to mask spots the toner did not stick to. toner resists ferric chloride fairly well.
(DIR) Post #Ahzoo7B09LoNE12Qu8 by homelessjun@mas.to
2024-05-17T21:15:33Z
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@foone also, laser printers changed things a lot..
(DIR) Post #Ahzp7TFQJUMrBEKuOm by homelessjun@mas.to
2024-05-17T21:12:50Z
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@foone photolamps were cheaper and often faster.
(DIR) Post #AhzpDbuh0XAVnGZETw by lp0_on_fire@social.linux.pizza
2024-05-17T21:17:11Z
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@foone, you are, of course, hoping that the company manufacturing your board gets it right.https://www.revk.uk/search/label/PCB
(DIR) Post #AhzpNObtK7nXQjRHwu by foone@digipres.club
2024-05-17T21:20:52Z
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@cadey you have big pockets
(DIR) Post #AhzpTOEhcwHk0XS1S4 by The4thCircle@mastodon.gamedev.place
2024-05-17T21:22:01Z
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@foone I always wanted to do that when I was younger but I was worried about the corrosive chemicals.That said these days you could probably do it with Cillit Bang.
(DIR) Post #AhzpaHdyXHDVaZYjcu by davbucci@mastodon.sdf.org
2024-05-17T21:22:33Z
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@foone A trick that I used back in that time (UV sensitized boards were too expensive for me) is to photocopy on ordinary paper the circuit, then put it on top of a bare copper clad board, use a nail to gently mark the position of each hole through the paper, use a pen to trace manually the tracks by copying the best I could the tracks and finally etch the board and drill the holes. You save the UV transfer project, but it quite error prone and slow.
(DIR) Post #Ahzpi8uos53cpqBYzg by peaceman@mastodon.social
2024-05-17T21:24:08Z
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@foone it worked pretty well, i used to do this a lot. I usually xeroxed the layouts (to not cut into my precious magazine, or since they printed on both sides) and sprayed the paper with some orange-smelling oil to make it more transparent AND stick to the PCB's photosensitive layer. Exposed with a 300W Osram Vitralux for 4 minutes. Develop in NaOH, etch in FeCl3.
(DIR) Post #AhzpsfIRKnMI9uFdKa by chfour@wetdry.world
2024-05-17T21:24:27Z
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@foone you can still do that if you want to bang out prototypes fast! or if you just find it cool to make your own pcbsi do find it pretty cool and what i recently came up with is to use a dlp projector with the color wheel removed and a high-power uv led instead of the lamp, a'la photolithographyi found a cheap 1024x768 dlp projector and i calculated that if i focus that to an area of 81.92x61.44mm i should get 0.08mm pixels which is pretty neat (for comparison a tqfp144's leg is ~0.22mm wide) but we'll see how that goes lol
(DIR) Post #Ahzq8MKtb2SjzHspkG by keithmann@mastodon.online
2024-05-17T21:27:43Z
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@foone I always used the Letraset-style stickers and a special marker pen. You needed a drill press, too, unless you were doing surface-mount (which I don't think we'd even heard of).
(DIR) Post #AhzqJDhW2fRQOKdtwG by X31Andy@mastodon.green
2024-05-17T21:30:32Z
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@foone I'd forgotten those boards in the mags back in the 1970s and 1980s. A real trip down memory lane.
(DIR) Post #AhzqOSMqwH1RKMTULw by four0four@ioc.exchange
2024-05-17T21:32:45Z
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@foone there were also these kinda neat rub-on transfers - The ones I had were intended to directly be etch resistant, but I'm sure you could use them as a mask just as readily. I've extremely vague memories of similar transfers being somewhat common in offices (for office purposes) at the time too.This is the only picture I could find of exactly what I used: https://www.reddit.com/r/nostalgia/comments/msxdex/radio_shack_archer_dry_transfer_patterns_for/It seems like you can still source variations, though?? https://www.electronicplus.com/content/ProductPage.asp?maincat=pc&subcat=pca
(DIR) Post #Ahzr6ZngfIZn7b42OO by flexplate@mas.to
2024-05-17T21:37:25Z
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@foone I'm pretty sure that you could use a resin 3d printer to do the photo-resist part of the process nowadays, cutting out a lot of the arts and crafts and just leaving you with the ferric chloride bath and interminable drilling.
(DIR) Post #AhzrCuwSyS72QdC68e by jordan@sometimes.social
2024-05-17T21:39:08Z
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@foone Aha so it is (it's a schematic though, not an actual layout)
(DIR) Post #AhzrK49v6V652dtb72 by raptor85@mastodon.gamedev.place
2024-05-17T21:43:53Z
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@foone that's still how most people do it though, usually you just send off for a more cleanly/professionally made one later. You can go to any microcenter and still buy coated PCBs and copper etchent. I always preferred the "iron on" process to the photoresist process though as it's a lot cheaper than buying the photoresist coated boards. (glossy paper, laser printer, toner transfer to the copper coated board with heat, then dip).I just mill test boards now though, way easier/cheaper.
(DIR) Post #AhzrRrAfHDgP4oxVpY by darkling@mstdn.social
2024-05-17T21:49:57Z
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@foone Oh, I don't think that was Geoff's problem. He was definitely on the agricultural end of things with his designs. He just found it hard to put the drill in the right place every time. :catsmile:
(DIR) Post #AhzrhRgdnJF0fjLgmm by foone@digipres.club
2024-05-17T21:50:54Z
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@vxo Did you ever see my Copy Pro Control board? I still made it in Kicad so I couldn't get to weird with it, but I did attempt to get as Weird as possible given the circumstances.
(DIR) Post #AhzrnMtQWwX9Xf9aAS by eichin@mastodon.mit.edu
2024-05-17T21:52:36Z
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@fooneThough at that point you could also get both the chemicals and the treated plates at your nearby Radio Shack...
(DIR) Post #Ahzs9aTWiEbE2NdM6y by whitequark@mastodon.social
2024-05-17T21:53:40Z
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@foone you can still do this todayi worked on a DIY process for PTH metallization
(DIR) Post #AhzsJq0nnnWT7T5Odc by dunkelstern@kampftoast.de
2024-05-17T21:57:06Z
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@foone If you want to be stunned though look into what a gerber file defines and how that production process used to happen. Hint: It defines apertures for a moving UV light ;)
(DIR) Post #AhzskybTy0HJaJBRKa by f4grx@chaos.social
2024-05-17T22:01:35Z
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@gsuberland @foone ferric perchloride is so old school and annoying. copper chloride is the way to go. in practice that just means hcl with a pinch of h2o2. when depleted it can be replenished with an air bubbler.
(DIR) Post #Ahzsl0wpFcXUr5BVsO by kurth@social.tchncs.de
2024-05-17T22:08:34Z
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@f4grx @gsuberland @foone yeah, remember those dirty balls
(DIR) Post #Ahzsl2C6cIM8ilLEKe by foone@digipres.club
2024-05-17T22:11:13Z
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@kurth @f4grx @gsuberland these look tasty. some kind of fried chicken!
(DIR) Post #AhzszWGPcFNQ2AGLia by Jencen@furry.engineer
2024-05-17T22:14:12Z
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@foone Huh. wonder if that was the original idea for them. I'd always thought it was for component ID/location. but possibly a way to replicate them o.o
(DIR) Post #AhztAJttvDTKsMspeK by rubinjoni@mastodon.social
2024-05-17T22:17:48Z
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@foone Beats gerbers.
(DIR) Post #AhztILHqeSw7UYuTTc by cadey@pony.social
2024-05-17T22:34:54Z
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@foone no i don't
(DIR) Post #Ahzub8UoX2ZHHIV3bs by SteakPinball@mastodon.social
2024-05-17T23:31:54Z
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@foone In high school we drew sharpie directly onto the board as the mask.
(DIR) Post #Ai03PKF5vrOFozafbs by tursilion@furries.club
2024-05-18T01:11:39Z
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@foone I made a fair number of manually taped boards, but I never did the photoresist.I barely remember laying down the tape though, so I can't even comment if it was hard or not. I feel it must have felt pretty trivial. But damned if I remember how I got the traces in the right places. I DO remember floating the boards in the acid bath and what happened if you left them too long. ;)
(DIR) Post #Ai0GUG8nuKfLx9Ka8m by crazybutable@mastodon.social
2024-05-18T03:38:54Z
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@foone you used to be able to transfer the print off certain laser printers/copiers right onto the PCB with the right combination of chemicals
(DIR) Post #Ai0Poes4ZQGG20J5Jg by clairely_undaunted@mastodon.triggerphra.se
2024-05-18T05:23:28Z
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@foone yeah! my dad had a subscription to that, was fascinating looking at layouts
(DIR) Post #Ai0avwo9Na6hBT9ORk by ppxl@social.tchncs.de
2024-05-18T07:28:02Z
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@foone I feel this is what a lot of makers are still doing 😅
(DIR) Post #Ai0cUOQ9K07UcjufGi by burtyb@widget.uk
2024-05-18T07:45:30Z
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@foone iirc 30 years ago I would have been using CAD (with parallel port dongle), stacking transparencies for better contrast, using a homemade light box and then sticking the PCB in a repurposed sandwich box full of ferric chloride 😆.
(DIR) Post #Ai0cviHXaPmM2aui2K by burtyb@widget.uk
2024-05-18T07:50:08Z
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@foone in reality it was a pita as whatever was on the other side of the thin magazine page would sometimes show up in a photocopy ☹️.
(DIR) Post #Ai0qQb8jUO54GsqpWq by sannemen@mastodon.social
2024-05-18T10:21:35Z
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@foone 15-20 years ago, UV photoresist was the “fancy” way of doing it in my uni in Brazil.Usual one was, photocopy the design in the darkest setting to get as much toner as possible stuck to the page (thin paper worked best), then use a clothes iron to heat transfer it into a bare copper board.Dissolve the paper in water, then throw the board into an FeCl3 solution to eat away the bare copper and leave the covered traces behind. Then scrub with IPA to clean it, and drill.
(DIR) Post #Ai27oDn1qfA7BIVeO8 by vxo@digipres.club
2024-05-19T01:11:02Z
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@foone I love it!!
(DIR) Post #Ai2Ls6G9BdaELJsBd2 by timixretroplays@digipres.club
2024-05-19T03:48:37Z
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@foone @vxo best easter egg hunt
(DIR) Post #AiUVlZi7OswHByFySW by jabawack81@mastodon.social
2024-06-01T17:50:54Z
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@foone I'm old enough to remember doing a couple of projects like this in school, and IMHO, it's a more civilised way to build PCBs for small projects;)
(DIR) Post #AlEl7KGPWcPFU2WN8K by penguin42@mastodon.org.uk
2024-08-22T21:03:12Z
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@foone Right; there is an even easier way if you weren't copying a magazine, which was to draw directly on a (non-photoresistive) PCB with a special pen, or with special tape or transfers; then you just needed one simple chemical (Ferric chloride) to etch it; a few of us did that at school (in the late 80s) - it was OK for simple things and didn't need any equipment other than a plastic tub.Drawing/tape on photomask was the normal commercial way of doing (small run?) PCBs.