#qi-hardware IRC log for Friday, 2014-02-21

whitequarkwpwrak_: forgot to turn it off06:54
whitequarkrather I *thought* it was turned off06:54
whitequarkbut it wasn't, and the air stream tripped some switch or somesuch06:54
whitequarkresulting in quite entertaining picture with flames erupting out of every hole06:54
wpwrak_the fact is that it's not because of russian customs that electronic toys don't reach you. what really happens is that they fight all the way against being shipped once they find out you're their destination :)06:57
whitequarkbut, so far all the toys have reached me easily!07:08
DocScrutinizer05whitequark: (galden test) I still can spot some liquid moving along the "corner" of the glass, when tilting and spinning it07:21
DocScrutinizer05soon it will be too spread over the glass surface to spot it anymore07:22
Action: DocScrutinizer05 wonders what's with https://github.com/Pinoccio/pinoccio-hardware-reference/blob/master/pdf/pinoccio-sch-v0.13.pdf - looks rather normal and boring. A bit too "eagle-y", I honestly despise that style07:25
DocScrutinizer05it always looks a bit like a mixture between school first class "I learn to write AAAAA BBBBB..." and a strange reminiscence to windows2.x resp DOS07:26
DocScrutinizer05maybe Hercules gfx07:26
wpwrak_use kicad :)07:32
DocScrutinizer05how will that change https://github.com/Pinoccio/pinoccio-hardware-reference/blob/master/pdf/pinoccio-sch-v0.13.pdf ?08:58
whitequarkheh. now twitter suggests me to follow almost exclusively heise-related accounts, and google puts the first link to a german page like third of the time10:04
whitequarkit's quite creepy10:04
whitequarkooh, my hotbed magnetic stirrer has arrived10:33
DocScrutinizer05magnetic stirrer, doesn't sound particularly useful for electronics purposes. Rather an equipment for chemical lab10:38
DocScrutinizer05but hey, maybe makes for a geeky teapot warmer with automatic stirring. Ideal for rock sugar ;-)10:39
whitequarkI've got it for etching and preparing other solutions10:40
whitequarkmainly for etching though. remember our discussion?10:40
DocScrutinizer05ooh, for preparing solutions it's for sure convenient10:40
DocScrutinizer05sure I remember10:40
whitequarkhrm. temperature not adjustable... fixed at 100°C10:41
DocScrutinizer05thought I been able to convince you not to waste money on that 10:41
whitequarkouch indeed10:41
DocScrutinizer05so not even useful for teapots10:41
whitequarkwell, I'm pretty sure it's adjustable with a spare resistor or something10:42
DocScrutinizer05who knows10:42
DocScrutinizer05I've seen room heater fans where the fan motor been on a resistive voltage divider built from the heating err wires10:43
DocScrutinizer05extremely nasty and scary design10:43
whitequarkwow, it is so extermely... soviet in design10:48
whitequarkmanually soldered lm317 with legs bent *sideways*10:48
whitequarkno, I should just take a photo of this10:49
whitequarkthat's basically all it has10:52
whitequarkactually I don't think it is thermoregulated *at all*10:52
whitequarkalso note the chipped "PCB"10:53
whitequarkit's not even FR4, it looks more like cardboard10:53
whitequarkno mask, flux all over... hrm10:55
whitequarkyep. there is absolutely zilch thermoregulation measures. it's just a nichrome wire plugged right into mains11:00
whitequarkWTF I even bought11:00
DocScrutinizer05imgut down11:12
DocScrutinizer05>>Imgur is over capacity!11:13
DocScrutinizer05Sorry! We're busy running around with our hair on fire because Imgur is over capacity! <<11:13
whitequarkf5 it11:14
DocScrutinizer05wow, it worked11:14
DocScrutinizer05cool russian design, pretty futuristic11:16
whitequarkif by "futuristic" you mean "from the age where word 'futuristic' was cool beans"11:16
whitequarkthen yes :D11:16
DocScrutinizer05I'm amazed they wasted a second mount post for the PCB11:16
wpwrak_lovely FR2, too. very smoothly broken. made at "angry ivan fabs" ?11:17
whitequarkwpwrak_: yeah, locally made11:17
wpwrak_(cardboard) well, that's what FR2 basically is :)11:18
whitequarkI should've known better11:18
whitequark"made in russia" is the biggest ever warning flag you can see11:18
larsc'made in germany' was meant as one as well11:18
DocScrutinizer05on tanks and other heavy steel stuff it's not all that bad11:18
wpwrak_you need those tanks if yo8u have that sort of equipment in your lab ...11:19
whitequarkwell... AK-74 is pretty good11:19
DocScrutinizer05I had a multimeter from USSR, came in a nice steel mini suitcase11:19
DocScrutinizer05and wasn't completely useless 11:20
whitequarkDocScrutinizer05: have you got a hernia from it?11:20
DocScrutinizer05nope, it was "small"11:20
whitequarklarsc: I dunno, here "germany" = "quality" pretty much11:20
whitequarkthere's even an idiom, "exemplary german quality"11:20
whitequarkand "exemplary german order"11:21
DocScrutinizer05I used the suitcase later on to pack a 10Ah bike battery into it and connect that to a selfmade 50W flood lamp11:21
DocScrutinizer05made from a car fog light11:21
whitequarkI see why you put "small" in quotes11:21
whitequarkdid you mean "it was somewhat smaller than a tank" ?11:21
larscwhitequark: but it was introduced as a warning sign in GB after the war11:22
larscit turned on them quite quickly though11:22
DocScrutinizer05well, yes. That's about the right description11:22
larscok, not after the war11:22
whitequarkhmm weird. there's a few patches left on board, which basically don't want to etch11:25
DocScrutinizer05I had a tiny bench vise made in USSR, which been extremely cheap (some 5 deutschmarks) and worked fine, despite the whole thing been covered by filler paste to get it in shape prior to painting it in usual metallic blue11:26
whitequarkmost of the copper thickness was removed, so it's not surface thing11:26
whitequarkseems kinda like crystals if you look at it at an angle. you know, like zincified steel11:27
whitequarkthis kind of reflection11:27
DocScrutinizer05copper impurities?11:27
whitequarkand it just sits there for 10 minutes already and doesn't etch, despite all other parts etched fine11:27
whitequarkwell idfk11:27
Action: wpwrak_ wonders how much longer until you give in and get the HCl ;-)11:27
DocScrutinizer05russian product?11:28
wpwrak_russian chemistry. probably too radioactive. disturbs the chemistry :)11:28
whitequarkDocScrutinizer05: nope, MGChemicals11:28
whitequark... same guys who sold me that shitty printer film11:28
DocScrutinizer05I mean the PCB11:28
whitequarketchant is russian11:28
whitequarkwpwrak_: what?11:29
DocScrutinizer05they seem to be experts in fake sub-par quality stuff11:29
whitequarkDocScrutinizer05: I even scratched that copper and... newsflash... NOTHING HAPPENS11:29
whitequarklike it just sits there with a scratch11:29
wpwrak_"etchant is russian" that explains it :)11:29
whitequarkhow on earth scratched copper in etching solution is not etching11:29
DocScrutinizer05well, when it's no copper11:30
DocScrutinizer05simple as that11:30
whitequarkok, it's definitely not going to etch11:30
whitequarklemme just throw another chunk of PCB there, even without resist11:30
DocScrutinizer05make MGChemicals eat it!11:31
whitequarkI should leave another angry Amazon review11:31
wpwrak_maye sure you scrub off the oxides first11:31
DocScrutinizer05err, depending on etching fluid you usually don't need to worry about oxides11:32
whitequarkwpwrak_: I didn't do that and it etches just fine11:32
wpwrak_yes, but since it already acts kinda weird in that role, i'd try to even the odds11:32
DocScrutinizer05it's rather like etching fluid is like very strong flux11:32
wpwrak_ah, good. maybe the other one just had some odd contamination.11:33
DocScrutinizer05impurity, told ya11:33
whitequarkwpwrak_: no, I mean at surface11:33
whitequarkthe other one was just fine at the surface as well11:33
whitequarkit's just at the end of etching where the devil hides11:33
wpwrak_with toner transfer, some adhesive residue is often the culprit if something just doesn't want to etch11:33
DocScrutinizer05some bored worker threw his snack wrapper paper on the copper bar before it gone thru the roles thinning it11:34
wpwrak_well, etching is always at the surface. if it's not exposed, it won't get etched :)11:34
whitequarkoooh wait, interesting effect11:34
wpwrak_now comes the cold fusion11:34
Action: wpwrak_ turns on CNN11:35
whitequarkI think I figured it out11:35
whitequarkthe etchant is too concentrated11:35
DocScrutinizer05or even a beer bottle lid11:35
larscthe cold fusion?11:36
whitequarkin fact it is concentrated enough that when I place a board in it, the etchant *crystallizes on the board*11:36
wpwrak_quick, describe it before the radiation kills you11:36
whitequarkliterally, there appear hard white crystals on the surface11:36
whitequarkobviously preventing any more access to the copper11:36
DocScrutinizer05that's kinda same effect as with acid in steel tank11:36
DocScrutinizer05old news11:37
whitequarkand if I wash it under tap water, they just wash away, meaning they're water-soluble11:37
whitequarkDocScrutinizer05: passivation is a different effect11:37
whitequarkbut I see what you mean11:37
DocScrutinizer05the copper salt created from copper and etchant still needs to be able to solve in the liquid11:38
DocScrutinizer05in a saturated solution this will probably fail11:38
DocScrutinizer05btw you're not supposed to use 99% alcohol for desinfection. Kinda for same reasons11:39
DocScrutinizer05bacteria just dehydrate and survive11:39
whitequarkoooh you're right11:39
whitequarkcould be CuSO411:40
whitequarkinstead of etchant11:40
whitequarkor even a mixture of both11:42
whitequarkit surely looks like copper crystals...11:45
wpwrak_with HCl + H2O2, you can tell simply by the color if the chemistry is right :)11:46
whitequark"if your face is blue, you're doing it just right?11:46
whitequarkanyway, failboard: http://imgur.com/SKMWPU6,WZhM5ql11:49
whitequarkDocScrutinizer05: hmm?11:50
DocScrutinizer05shit happens11:50
whitequarkyeah it is rather horrible11:50
DocScrutinizer05but interesting11:50
whitequarkyeah, do you see those 'crystals'?11:51
whitequarkthey're much more evident in person11:51
whitequarklike it has very characteristic alternating-matte-and-gloss surface of zinc coatings11:52
whitequarkDocScrutinizer05: on a second thought I think you're exactly right about passivation11:54
whitequarkif the copper was covered by reaction product = CuSO4 this is exactly what passivation is11:54
whitequarksame as in oxide case11:54
whitequarkI should write a note about all this crap11:55
wpwrak_so 100 um traces are about where you should stop. maybe even 150 um, to have a bit of a margin. not too shabby.11:59
whitequarkwpwrak_: keep in mind it's ridiculously overetched12:00
whitequarkit was in solution at least 2x longer than it should have been12:00
wpwrak_sure. but it's also good to have a bit of a reserve12:00
whitequarkin fact for 100µm and 50µm resist simply detached from traces12:00
wpwrak_besides, you probably won't use any components that needs that fine traces anyway ;-)12:01
whitequarkthat's true too12:01
whitequarkoh and it's not actually 50µm and 100µm. printer has screwed up.12:01
whitequarkso it's just a pile of various screwups :)12:01
DocScrutinizer05wpwrak_: you should read his fine "paper"12:01
wpwrak_so how much is it ?12:01
DocScrutinizer05and watch the awesome test PCBs there12:02
whitequarkwpwrak_: let's measure. the pcb is 32mm wide.12:02
DocScrutinizer05pretty much to the resolution of the resist12:03
DocScrutinizer05don't bother, that's futile effort12:03
whitequarkwpwrak_: think DocScrutinizer05 means this: http://lab.whitequark.org/notes/2014-02-16/optimizing-for-best-photoresist-adhesion/12:03
whitequarkDocScrutinizer05: why?12:03
whitequarkI'm going to measure it by looking at photo in GIMP12:03
DocScrutinizer05what do you learn from measuring trace width on that messed up board?12:03
whitequarkyou're right actually12:04
DocScrutinizer05yes, that one12:04
DocScrutinizer05you can learn form TAHT12:04
DocScrutinizer05THAT even (http://lab.whitequark.org/notes/2014-02-16/optimizing-for-best-photoresist-adhesion/)12:04
DocScrutinizer05not his horror PCB12:05
DocScrutinizer05a piece of artwork12:05
whitequarkglad you like it :D12:06
DocScrutinizer05http://lab.whitequark.org/images/photoresist/2014-02-13/try-9-highlights.jpeg :-D12:07
DocScrutinizer05I'd say 0.10 has already plenty of safety margin12:07
DocScrutinizer05though for a true test you'd have to chech trace pitch, not trace width12:09
DocScrutinizer05like 5 lines plus 5 gaps on 1mm12:09
whitequarkright... could make that test too12:09
whitequarko/ sleep12:17
DocScrutinizer05you got very weird sleep schedule12:33
DocScrutinizer05says the guy living his 30h day in JRTZV12:34
larscthanks to all the ESD in the lab I don't even have to touch the reset button anymore to reset the board16:01
wpwraklarsc: ask them to open a lab in buenos aires. more than enough relative humidity to never have to worry about ESD ;-)18:44
larscI asked to be transferred to austraila for the winter months here in germany19:07
larscthat request got declined19:07
larscnot sure if bunenos aires will work19:07
wpwrakit's much closer than .au :)19:20
wpwrakor maybe brazil. rio also has a nice and humid climate :)19:20
pcercueiI'd totally go to Buenos Aires19:26
larscthe problem is to get approval19:29
pcercueiquit your job ;)19:29
wpwrakpcercuei: any hand to kick to get the KK out would be welcome ;-)19:29
wpwrakKirchneristas, affectionally called KK, pronounced ka-ka, ...19:32
pcercueiit's a political party?19:33
pcercueianyway. off to get a beer :p19:34
pcercueior eight19:34
Action: pcercuei afk19:34
--- Sat Feb 22 201400:00

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