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<kyak>
!seen tuxbrain
<qi-bot>
kyak, tuxbrain? hmm... I'm trying to remember... maybe... I'm not sure... no. I don't remember tuxbrain.
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<wpwrak>
NickSydney: interesting. but is the purpose to help or to intimidate ? :) if i didn't already know what "true && { echo success; } || { echo failed; }" does, i might think i'd never understand after reading the analysis ...
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<qwebirc25409>
wpwrak: i guess the website is suitable for n00b like myself :)
<wpwrak>
in general, pretty much any laser that puts a significant amount of toner on the paper should do. so "eco" or draft modes may get in the way ... until you find out how to turn them off
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<nicksydney>
hmm
<wpwrak>
each step of the process matters :) so the printer is one variable
<wpwrak>
the paper is usually more critical. there's a lot that can go wrong there. you'll probably need to try a few different papers.
<wpwrak>
(incomplete and old, but has more or less that complete process)
<wpwrak>
if you can get the HP C6039A paper, that would be best. not sure if it's still around, though
<wpwrak>
else, you have to make a localized approach. you may also find help in local electronics enthusiast's fora
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<wpwrak>
in general, google for printer name plus "toner transfer" (with the double quotes). that's likely to turn up experiences with that printer among the first hits
<wpwrak>
then, print name plus linux to see if it's friendly
<wpwrak>
you may also want to get a permanent marker with a very fine tip, to cover any spots where traces got interrupted in the print/transfer. (like the ones marked red at the bottom of the left column)
<wpwrak>
if you miss any of these things you can also fix them with solder, but it's more convenient if you don't have to
<wpwrak>
ah, and regarding the instructions, i wouldn't use ferric chloride anymore. nowadays i use muriatic acid with peroxide. cheaper, easier to get, cleaner, faster. drawback: not so nice to do indoors.
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<nicksydney>
wpwrak: that doc is really thorough
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<wpwrak>
the soldering part is a bit obsolete. back then i stoll thought ssop were kinda difficult. nowadays, i solder them by just "painting" the solder. quicker and safer than the process i described there.
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<DocScrutinizer05>
muriatic acid?
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<wpwrak>
"salzsaeure"
<wpwrak>
HCl + H2O2 is a LOT better than ferric chloride. you can find the ingredients everywhere, it's a clean liquid and it stays clear (unlike FeCl with all the black sludge building up in there), it works perfectly at room temperature (FeCl: wants heating), and you can just store and reuse it
<wpwrak>
i keep mine in a glass jar with a flat bottom and a tightly fitting plastic cover. that way i don't have to move it between storing and etching. if it gets weak, i add a bit of peroxide or acid. every year or so, when the volume gets too large, i put a bit into a larger kjar. so this means basically no residues. (until i want to dump the large
<wpwrak>
jar, but that one also has its uses for bigger items)
<wpwrak>
to keep the volume increase low, i use 35% peroxide to "reactivate" the mixture.
<whitequark>
wpwrak: peroxide is a regulated substance in quite a bit of countries afaik, it being a precursor
<whitequark>
oh and muriatic acid too
<wpwrak>
well, peroxide at a low concentration is a desinfectant. you should be able to get at least that (at any pharmacy). the stronger stuff may be more difficult
<whitequark>
yes, I think peroxide is 15-30ml max
<whitequark>
and it's not concentrated at that
<wpwrak>
muriatic acid should be at any hardware store :)
<whitequark>
no
<whitequark>
it's a precursor
<whitequark>
here you can only buy via bank transfer from a company account
<wpwrak>
yeah, the weak peroxide will do. you just ,ay not be able to reuse it so well
<whitequark>
same for KMnO4 and pretty much any interesting compound
<whitequark>
except probably diluted H2SO4 which is used in Pb rechargeable batteries
<wpwrak>
HCl ? you should come to argentina and buy a few canisters of it ;-)
<whitequark>
yeah, good luck transporting that back :p
<wpwrak>
hcl is used to balance the acidity of swimming pools. so pool supplies may be a place where you can find it
<whitequark>
see above, bank transfer from a company account
<wpwrak>
i think it's also used for pipe cleaning or such. maybe you can find something that's 99.9% HCl, 0.1% perfume, and has an innocent-sounding name ;-)
<whitequark>
well, I think I could buy HCl if I ask around and find someone not related to retail, i.e. ask directly at the factory
<whitequark>
there has been wide reports of success this way
<whitequark>
but it's by no account "easily obtainable"
<wpwrak>
okay, not in russia then
<mth>
I thought pipe cleaning was done with bases rather than acids? or are both possible?
<wpwrak>
i heard that story of, one upon a time, cotton barons lobbying for banning hemp on the reason of its potential use as a drug, to get rid of the competition. maybe something like that happened with HCl in russia
<whitequark>
^ yeah, here concentrated NaOH is used for that
<wpwrak>
mth: i don't know really what they use it for. i just know there's half a rack full of it in the plumbing section, bottles of 1 l and canisters of 5 l
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<wpwrak>
that is, it looked like that about a year ago or so. i have some 7.5 l stocked (i'm not quite sure what i thought back then i'd need all that stuff for), so with an annual consumption of about 1-2 dl, i'm beginning to get interested in longevity research
<sanderr>
Where do you go with the used fluids?
<wpwrak>
i'd take off the lid and leave the jar outside. that why the water evaporates and i get a small quantity of solids. these go in the trash.
<wpwrak>
but most of the liquids can just be reused. you only need to discard them if they get contaminated with something.
<wpwrak>
in the absence of contamination, i.e., if you discard a batch because its has gotten overly diluted, you could probably also recycle the solids.
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<sanderr>
Ok, that's clear. :)
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<wpwrak>
when you let it dry, it forms pretty blueish-green crystals. much nicer to look at than the black-brown sludge FeCl becomes. plus, if your neighbours have seen "Breaking Bad", you can tell them you're improving on Heisenberg's formula :)
<whitequark>
*g*
<wpwrak>
(well, don't tell them in they're likely to try to get a sample :)
<wpwrak>
s/in/if/
<qi-bot>
wpwrak meant: "(well, don't tell them if they're likely to try to get a sample :)"
<mth>
wpwrak: be careful that your container lasts that long; my father had kept old photography chemicals and many years later the plastic bottle started leaking
<whitequark>
in my experience plastic (polystyrene) lives under a year. after that, it becomes extremely brittle, but doesn't leak very much until you try to touch the bottle.
<whitequark>
it is ostensibly acid-resistant, and the basic chemical probably is, but then there's plastificator
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<wpwrak>
mth: i have plastic bottles in a plastic box stored outside (on a ceramic floor, a good distance from the drain)
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<wpwrak>
need to replace the box, though. it didn't like the last storm ...
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<wpwrak>
the bottles are several years old. and yes, they feel a bit brittle. the main problem isn't liquid leakage but gas leakage. i had one under the kitchen sink for a while. then i noticed that all the metal parts in the area were heavily oxidized. than's when it moved to the terrace.
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<DocScrutinizer05>
haha
<DocScrutinizer05>
yeah, you should probably put bottles with corrosive liquids into a larger airtight box with some passivator or absorbant stored in the box as well
<DocScrutinizer05>
e.g a dish with naOH
<DocScrutinizer05>
NaOH even
<DocScrutinizer05>
or some other alkali substance
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<sanderr>
There's so much fun in open hardware. You learn about chemistry, electronics, computer science, mechanical engineering and everything in between. :)
<sanderr>
Even human psychology.
<larsc>
and economy
<DocScrutinizer05>
and a lot about medical treatment ;-)
<whitequark>
oh?
<larsc>
re-attaching limbs and such ;)
<DocScrutinizer05>
yeah, burns, scratches, cuts, injury from various chemicals...
<DocScrutinizer05>
curing with other chenicals ;-) (acrylate works great for small cuts)
<DocScrutinizer05>
(also for broken nails)
<whitequark>
hnggg broken nails :/
<larsc>
silver nitrate
<DocScrutinizer05>
eew
<DocScrutinizer05>
yeah that's nasty
<DocScrutinizer05>
though rather rarely needed in electronics
<larsc>
good for sealing wounds though, the color takes a while to wash though
<DocScrutinizer05>
hmm, I guess you can use alaun for that
<DocScrutinizer05>
less agressive and toxic
<wpwrak>
DocScrutinizer05: (airtight box) naw, they're free to gas out into. the wind will take care of them. and i wouldn't want to have a passivator that has an exothermical reaction in there. having one bottle leak is one thing, melting holes in all of them and the outside container is quite something else :)
<DocScrutinizer05>
ooh, english term is alum
<DocScrutinizer05>
hmm yeah
<DocScrutinizer05>
you probably want to use a passivator that's not that reactive
<DocScrutinizer05>
a few shells or sth like that
<wpwrak>
if it gets out, i'll be exposed to evaporation :) if it gets out in the middle of a thunderstorm, it'll be massively diluted before it goes down the drain
<DocScrutinizer05>
nah, i'm talking about storing such stuff indoors
<DocScrutinizer05>
corrosion of all metal in reach of acid bottles is a known problem, which you can counteract by wrapping the acid bottles into something to passivate the fumes
<DocScrutinizer05>
maybe a cloth you tintured with baking soda may do
<DocScrutinizer05>
tinctured*
<wpwrak>
hmm, i think i'll leave it just outdoors :)
<DocScrutinizer05>
Natriumhydrogencarbonate actually, you don't want the acid in it
<DocScrutinizer05>
sure, outdoors is always a safe bet (unless you face other threats when you keep it there)
<DocScrutinizer05>
WTF?
<DocScrutinizer05>
OMG!
<DocScrutinizer05>
USB Type-C
<DocScrutinizer05>
God forbid!
<DocScrutinizer05>
why did EU and China say "charging only via USB", anybody?
<wpwrak>
and there i was, already feeling a bit bad about using micro when the world is still largely using mini :)
<DocScrutinizer05>
Seems we soon have more USB connector types than we used to have barrel connectors
<roh>
well.. lets see what happens. reversible, 100W OD... sounds too good. but if they make it work, could be nice
<wpwrak>
charging over USB makes a lot of sense since it's a nicely standardized interface. so far the theory ...
<roh>
s/OD/PD
<qi-bot>
roh meant: "well.. lets see what happens. reversible, 100W PD... sounds too good. but if they make it work, could be nice"
<wpwrak>
roh: 110 V, 1 A ? ;-)
<roh>
wpwrak: dunno exactly
<DocScrutinizer05>
mybe 50V 2A
<roh>
but they spec-ed 90W on poe 802.3at
<roh>
50-70V or so then.. on multiple pairs (all of them)
<DocScrutinizer05>
42V 2.5A
<roh>
one speaks lldp with the switch to discuss power requests when one needs more than 13.5W
<DocScrutinizer05>
isn't USB3 some 35V?
* DocScrutinizer05
honestly wonders when those standard-inventing dummies consider doing a *nice* one, with just golden pads and magnets under it
<DocScrutinizer05>
magnets in the plugs only, while devices have ferromagnetic material. and the plugs need a button to "short" the magnet internally, so any magnetic debris falls off the plug
<DocScrutinizer05>
maximum easy attaching of plugs to devices, even in cradle. easy removal, non-destructive even when done wrong
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<DocScrutinizer05>
and when you actually allow magnets in both the plugs and the devices, then you can even get very flexible coding of which plug matches where
<DocScrutinizer05>
a 3pole plug will just jump into place to a 8pin attachment field
<wpwrak>
i kinda doubt that magnets should be part of the solution. at these sizes, they would have to be terribly strong to hold the connector in place
<DocScrutinizer05>
you don't need insane microscopic plugs like 1.5mm barrel or micro-USB
<ysionneau>
win 47
<DocScrutinizer05>
with this sulution your plug cab be 5mm high and 20mm wide
<wpwrak>
i do :)
<wpwrak>
ysionneau: an no, you don't win ;-)
<ysionneau>
:(
<ysionneau>
next time maybe!
<DocScrutinizer05>
the problem why manufs want small plug formfactors is they want small holes
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<DocScrutinizer05>
actually they want no holes ideally (I *hear* Sean ;-P) - with that type of connector they can get that, so no more need to miniaturize
<ysionneau>
FYI if you are interested in buying a Milkymist One R3.5 or a Mixxeo board, please fill in this doodle: http://doodle.com/sbdnetqi4mrf7w9i
<rjeffries>
wpwrak microUSB is FAR more common than miniUSB. Another factoid: microUSB allows far more plug/unplug cycles
<ysionneau>
I'm gathering names, if I get enough (10?) names I can seriously think about starting another production run
<wpwrak>
rjeffries: (more cycles) at least that's what the spec says. i kinda wonder how they reach that conclusion, though :)
<wpwrak>
(more common) dunno. seems that all the spartphones are now micro. but all the rest still seems to be mini.
<wpwrak>
so maybe in 2032, when the patents expire, usb 7 will have nice connectors :)
<rjeffries>
yes Apple's Lightening is sweet connector. Too bad it is not opne...
<rjeffries>
Apple also has THE best power connector on their laptops, by a few kilometers
<wpwrak>
(volume) i still have a lot more devices that aren't phones than devices that are phones :)
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<DocScrutinizer05>
wpwrak: (small devices) so what, thinner than 4mm? smaller than 20mm?
<DocScrutinizer05>
the device that *nowhere* has a free area of at least 5*20mm is yet to get built, and I guess when it gets built, no micro-USB will fit in ;-)
<wpwrak>
maybe 20-50 mm for the sides, 5 mm for the thickness. that's about what you can do with Micro USB while still having something else in your device
<wpwrak>
yes, 20x5 mm would be about sufficient for micro
<DocScrutinizer05>
ehß
<DocScrutinizer05>
?
<wpwrak>
a micro receptacle is 3 mm tall. add a bit of clearance and a thin plastic case and you have 5 mm
<DocScrutinizer05>
so what?
<rjeffries>
wpwrak my perspective is not "what wpwrak has in his lab such as dev boards etc." but how many GAZILLION "things" in teh world use microUSB. It is a non-trivial delta with several zeros after the leading "1"
<rjeffries>
DocScrutinizer05 bless you sir, we understand that Neo900 is not designed as a thin and light device. many (almost all) current high-volume handsets are. so to each his or her own. compavt connectors are indeed a thing. ;)
<wpwrak>
hmm, midi instruments, full-size B or mini-B. digital camera mini-B, keyboard mini-B, RF keyboard, mini-B. okay, they all happen to be in my lab, but that's just because that's where i am most of the time :)
<DocScrutinizer05>
WTF?
<DocScrutinizer05>
how comes Neo900 in here and now??
<DocScrutinizer05>
>:-(
<rjeffries>
Neo900 is a cool device. It really is!
<roh>
rjeffries: maybe the connector is nice, but the cables are shit.
<wpwrak>
DocScrutinizer05: i think he's congratulating you on using a sturdy 6.3 mm audio connector ;-)
<roh>
lots of broken apple psu around here
<rjeffries>
all cables are shit
<DocScrutinizer05>
and so are Porsche, so what?
<roh>
they always break next to the connector/psu
<roh>
i havent had that problem with my lenovo psu.
<rjeffries>
Neo900 was not designed in an era when thin and light was the gold standard. and that's OK.
<DocScrutinizer05>
yes, so what?
<rjeffries>
am I mistaken? maybe Neo900 does use microUSB? if so, my apologies
<DocScrutinizer05>
how's that related to magnetic plugs that don't have to get inserted to devices?
<rjeffries>
magnetic connectors are a cool idea. I misunderstood (maybe) that you disapprove of microUSB. anyway, enough elctrons have been consumed.
<wpwrak>
that's the complementary Ford approach. he sent his men out to find parts that still looked good in discarded cars, so that he could make them less durable. apple fix the part users complain most about, then weaken something that used to work :)
<DocScrutinizer05>
which admittedly would need more surface on device than a microUSB
<DocScrutinizer05>
but I think that's irrelevant, for afore elaborated reasons
<rjeffries>
wpwrak ha dnot heard that Henry Ford story. Love it!
<DocScrutinizer05>
rjeffries: I said "yes, you need more area than a micro-USB or similar tiny connector needs, so you get magnets of sufficient strength. But that's irrelevant since devices have enough free surface to attach a 20*5mm magnetic contact there. And divices that are smaller than 20*5mm won't have a micro-USB anyway". wpwrak answered "no, 20*5mm is a KO criterion for that idea since OEM want to build small devices"
<DocScrutinizer05>
NB that a 10 pole magnetic connector device-side would need less volume than a micro-USB receptacle
<wpwrak>
would it ? you still need the contact surfaces (which could be shallow, so there you save volume) but then the metal blocks on which your magnets pull
<DocScrutinizer05>
blocks? I think a 0.2mm ferromagnetic layer is sufficient
<DocScrutinizer05>
0.2mm steel covered with the usual NiCuAg
<DocScrutinizer05>
embedded into the plastic case shell
<DocScrutinizer05>
a 1mm Neodyme magnet at one contact to fix orientation
<DocScrutinizer05>
thinking about it, I guess the whole thing needs 0.0 .. 20mm^3 volume, given you replace parts of the plastic shell with it
<wpwrak>
hmm, i wonder how thin you can make a ferromagnetic layer before it stops working as such. there ought to be some F = X*f(d) where X is surface, field strength, and such, and f(d) is a monotonously increasing function of the thickness of the ferromagnetic sheet
<whitequark>
very thin metallic foil is still highly magnetic
<whitequark>
but, the force can be negligible
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<DocScrutinizer05>
depends on saturation
<DocScrutinizer05>
eventually all atoms are polarized 8oriented) and the magnetic force will not increase much
<wpwrak>
isn't it more like how much of the field is absorbed by the ferromagnet ?
<DocScrutinizer05>
what means "absorbed"?
<wpwrak>
i.e., when you add arbitrarily thin sheets until the force on the last one added is below a threshold, then you have the thickness at which the corresponding portion of the magnetic field is used
<wpwrak>
i'm basically saying that shielding == magnetic force. not sure how close this is to reality
<DocScrutinizer05>
yes, that's when enough atoms of the ferromagnetic marerial are polarized to deviate and guide the magnetic field away from the next layer
<wpwrak>
yup
<DocScrutinizer05>
when you got a ferritechoke and you increase the current and thus magnetism, it at one point gets saturated and magnetic field escapes from the ferrite core
<wpwrak>
so i would expect the force to increase with thickness. of course not linearly. more like a log curve (too lazy to look up the right sort of function)
<DocScrutinizer05>
prolly it does
<wpwrak>
so the question is how much ferromagnet you need before you only get diminishing returns
<DocScrutinizer05>
you recall the cig paper magnet thingie I linked photos in here? the ferromagnetic patch is like 8*4mm and maybe 0.3mm thick. The force from that tiny neodyme magnet to this thing is in the 50g range (guessed)
<wpwrak>
hmm, not bad
<DocScrutinizer05>
the magnet itself is so thin it doesn't really show when embedded into the carton of the cover
<DocScrutinizer05>
maybe 1mm
<DocScrutinizer05>
maybe 1.5
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<wpwrak>
now you need to calculate the forces acting on the connector. cable weight, any pull caused by movement, then the lever effect of the plug
<wpwrak>
for the lever, you probably have a radio of 1:5 to 1:10
<wpwrak>
s/radio/ratio/
<qi-bot>
wpwrak meant: "for the lever, you probably have a ratio of 1:5 to 1:10"
<DocScrutinizer05>
make the "plug2 thin and the cable flexible
<DocScrutinizer05>
this of course defeates the "off-button" idea for the magnets
<wpwrak>
you mean "breakable". do you moonshine for apple ? ;-)
<DocScrutinizer05>
eh?
<wpwrak>
(off-button) yeah, that one's classical german over-engineering ;-)
<DocScrutinizer05>
breakable like "you can bend it by brute force"?
<wpwrak>
naw, flimsy so it's light
<wpwrak>
remember that you may have some 1-1.5 m of cable hang off the connector.
<DocScrutinizer05>
what's flimsy with a 0.5mm steel ?
<wpwrak>
i mean the cable ;)
<DocScrutinizer05>
sorry, afk
<DocScrutinizer05>
no, i mean to use silicon isolation instead crappy hard PVC, proper fine copper braid, and a steel wire for increased strength
<DocScrutinizer05>
there are cables strong and flexible like wool string
<DocScrutinizer05>
tronger probably
<DocScrutinizer05>
stronger
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<wpwrak>
the industry seems to agree that USB cables are weightless
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<wpwrak>
yeah. none specify the mass.
<whitequark>
quick, make a time machine!
<wpwrak>
54, 30, 12 ... so about 40 g for a total of 1 m cable plus a total of four usb-micro plugs
<wpwrak>
so you get a pull of about 60 g on an 1.5 mm cable. add lever and you magnet needs to be able to hold roughly a 0.5 kg force
<wpwrak>
add some margin and handling tolerances (e.g., if the user moves the device while attached) and you're at 1 kg
<DocScrutinizer05>
no way
<DocScrutinizer05>
this is a connection and not a stand
<wpwrak>
don't forget the lever
<wpwrak>
that is, unless the connector rotates freely :)
<DocScrutinizer05>
heck you're mad, with 500g perpendicular force I rip each micro-USB receptacke off the PCB
<DocScrutinizer05>
honestly, I dunno if you're trolling me
<wpwrak>
no, it's < 100 g perpendicular
<wpwrak>
but your contact surface is parallel to the connector surface. and one side will be small, hence the large lever
<DocScrutinizer05>
nonsense, I told you the "plug" is lower than wide
<wpwrak>
you mean shorter ? (distance from case)
<DocScrutinizer05>
and the distance between contacts and cable exit point maybe 1mm, maybe less
<wpwrak>
you still have the cable's bend radius
<DocScrutinizer05>
which is like 5mm max
<wpwrak>
more like 5-10 cm
<DocScrutinizer05>
for whatever crap you assume
<wpwrak>
with liquid helium, you get better flexibility, i give you that :)
<DocScrutinizer05>
yeah, trolling. Now I'm sure about that at least
<wpwrak>
"WARNING: do not expose to excessive heat (> 1 K)"
* DocScrutinizer05
wonders if wpwrak ever used headphones. Decent ones with a good cable
<wpwrak>
you can try it: take a micro usb cable, balance the plug on a finger tip. then add a weight on the exposed connector until it's more or less horizontal
<DocScrutinizer05>
not those which pop out of your ears when you push the cable
<wpwrak>
then you can calculate the force you're counterbalancing
<DocScrutinizer05>
DAFAQ micro-USB cable!!!
<DocScrutinizer05>
PVC shit!
<DocScrutinizer05>
cheap crap
<DocScrutinizer05>
and when I use a power cord I get a radius of 50cm
<wpwrak>
let's see if the pvc matters ... density is about 1.2 g/cm3
* DocScrutinizer05
headdesks and heads out
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<wpwrak>
how thick shall we assume the pvc is ? 0.5 mm ?
<wpwrak>
so the jacket (cylindrical) is about 5 mm^2
<wpwrak>
per meter that's .... 5k mm^3, or 5 cm^3
<wpwrak>
so about 6 g. reducing the estimate for the 1.5 m cable from 60 g to 50 g if using weightless neojoergodyne instead
<wpwrak>
so that's still a 0.4-0.8 kg force
<wpwrak>
now, balancing a 0.5 mm usb cable, i need at 20 mm a weight of ... 62.6 g
<wpwrak>
so about 1.2 mNm
<DocScrutinizer05>
now please do the same for carbonfibre-resin
<DocScrutinizer05>
or better: glass
<wpwrak>
err, make that 12 mNm. g = 10 N/kg, not 1
<wpwrak>
i already assumed it's weightless
<DocScrutinizer05>
I bet fibre-resin must have about the same specific weight as PVC (remarkably irrespective of the amount of softener in PVC)
<wpwrak>
now, if the force of the ... how tall was it ... 5 mm ? connector was about uniformly distributed, that would be 2.5 mm. so the magnet's holding force would have to be at least ... about 5 N for the 0.5 m cable
<DocScrutinizer05>
yeah, and when the moon was made of chestercheese
<wpwrak>
so for 1.5 m we get 15 N. you estimated the 8x4 mm patch to have about 0.5 N
<wpwrak>
can you actually measure it " attach some variable weight an see how far you can go until it separates
<wpwrak>
then measure the weight
<DocScrutinizer05>
I bet in 30 minutes you proved mathematically that you can't bend a knot ito a bamboo stick
<wpwrak>
well ... let's be generous. the bending radius will be reduced by having more weight in it, so let's say you need only 10 N
<wpwrak>
let's also assume you underestimated your magnet by a factor of 2 and it actually pulls 1 N
<DocScrutinizer05>
just *one* small hint: my "plug" is 20*5*3mm, and the cable comes out at the 5*3mm small end
<wpwrak>
this still means that you need a patch of about 12 x 24 mm.
<DocScrutinizer05>
and just maybe my cable is made of FPC
<DocScrutinizer05>
so 4mm wide and 0.3mm thick
<DocScrutinizer05>
and it has a bend radius of 2mm
<wpwrak>
Fragile Perishable Crap ? :)
<wpwrak>
yes, if you reduce the cable to nothing, then it works rather well :)
<wpwrak>
remember openmoko and the FPC fun with the debug board ? those were about 10 cm with usually very careful handling. i wish thee luck ;-)
<DocScrutinizer05>
remember I said *maybe*
<DocScrutinizer05>
I'm honestly bored about this discussion
<DocScrutinizer05>
[2013-12-04 18:58:32] <DocScrutinizer05> no, i mean to use silicon isolation instead crappy hard PVC, proper fine copper braid, and a steel wire for increased strength
<DocScrutinizer05>
and now, to annoy you, I reinforce my "crappy FPC" with a stainless steel fabric from both sides
<wpwrak>
i subtracted the weight of the outer PVC. so all that's left are the metals and the inner isolations
<wpwrak>
let me think of someone i really hate. someone you should hire for the customer complaints department :)
<DocScrutinizer05>
why me? I thought YOU will build those things
<DocScrutinizer05>
but yeah, we know you love to troll and criticize
<wpwrak>
indeed ;-)
<wpwrak>
and no, i'll stick with micro USB. let people complain to the USB-IF :)
<DocScrutinizer05>
they probably will complain that the USB plug is larger than your Y-thingie
<whitequark>
/rename #angry-joerg-ranting
<whitequark>
:p (not that I mind)
<DocScrutinizer05>
sorry, watching pages of meaningless math makes me feel like that
<whitequark>
I really don't mind, it's fascinating to watch
<DocScrutinizer05>
and it's not like I suggested to replace the mcro-B-plug at the end of an existing crappy cable by something that looks similar but works kinda different. I tried to explain and discuss a concept
<whitequark>
maybe there's samples of that already?
<DocScrutinizer05>
and the concept might include "cable: must have a bend radius of max 3mm and withstand 500g pull force" in the specs of the connector to define and maybe get produced
<wpwrak>
i just don't think that concept works at such small scales.
<DocScrutinizer05>
I don't see how specific weight of PVC comes in there
<wpwrak>
to calculate the weight of it. since you suggested to replace it with something lighter
<DocScrutinizer05>
lighter?
<DocScrutinizer05>
please point me to where I said anything about weigght
<DocScrutinizer05>
[2013-12-04 18:58:32] <DocScrutinizer05> no, i mean to use silicon isolation instead crappy hard PVC, proper fine copper braid, and a steel wire for increased strength
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<wpwrak>
you disagreed with my calculation of forces and then suggested to replace PVC with something thinner and supposedly lighter. of course, micro USB has a more forgiving geometry, so they're a bit lower there.
<wpwrak>
that steel cable will cost you, of course ;-)
<DocScrutinizer05>
I neither said thinner nor lighter
<DocScrutinizer05>
again:
<DocScrutinizer05>
[2013-12-04 18:58:32] <DocScrutinizer05> no, i mean to use silicon isolation instead crappy hard PVC, proper fine copper braid, and a steel wire for increased strength
<DocScrutinizer05>
I dunno, maybe that line gets filtered out at your side by some strange spamfilter
<wpwrak>
ah, i thought you disliked the PVC mainly for its weight
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<DocScrutinizer05>
and another again: my "plug" is 20*5*3mm, and the cable comes out at the 5*3mm small end
<DocScrutinizer05>
so no lever at all
<DocScrutinizer05>
the only lever you get is 20mm/bending-radius
<DocScrutinizer05>
I defined bendig radius as max 5mm
<DocScrutinizer05>
bending radius in this context of course needs a force too: 5mm when you pull the long non-fixed end of the cable with 30g, perpendicular to the fixed end of the cable
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<DocScrutinizer05>
the magnet the obviously needs a force of 50g or somesuch, for pulling apart (aka lift off)
<DocScrutinizer05>
the outer two contacts of the "plug" shall have slightly convex surface to fit into the concave contact pads on device
<DocScrutinizer05>
to avoid shearing
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<DocScrutinizer05>
actually better use conical shape for those, instead spherical
<DocScrutinizer05>
more tolerant to production deviations in dimensions
<DocScrutinizer05>
the contact at end of plug must be allowed to move ~0.5mm along the long axis of the plug, in relation to the other one at cable entry side
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<DocScrutinizer05>
hmm, no. make that a "roof shaped" contact with the roof ridge along the long axis of connector
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<DocScrutinizer05>
(([2013-12-04 18:51:55] <wpwrak> remember that you may have some 1-1.5 m of cable hang off the connector.)) No, that's not what this "plug" neither micro-USB is designed for. It should maybe be able to cope with 1m of cable hanging down from the micro-USB plug perpendicularly, but I already try to avoid that since N900 USB receptacles come off easily from PCB
<DocScrutinizer05>
the nice part in this magnetic connector is that it doesn't break when you abuse it like that. It simply disconnects
<DocScrutinizer05>
while for N900 microUSB such thing might end fatal
<wpwrak>
yes, that benefit is clear. the question is how to make it work such that it doesn't fall off all the time during regular use
<DocScrutinizer05>
by using a thin and flexible and lighweight cable
<DocScrutinizer05>
like used for good earphones
<DocScrutinizer05>
and that cable needs to get specified for bend radius aka stiffness and for strength of pulling it may cope with
<DocScrutinizer05>
in the spec of the plug
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<DocScrutinizer05>
s/plug/connector
<wpwrak>
hmm, i wonder about the stability. but then, maybe i've never seen what you would call "good" earphones
<DocScrutinizer05>
stability as in "it tears apart from pulling it"?
<DocScrutinizer05>
you can improve that by using one thin steel wire together with the copper braid
<DocScrutinizer05>
like a thin guitar string
<DocScrutinizer05>
maybe a tad thinner still
<wpwrak>
tensile strength, shearing, etc., the steel cable may actually make part of the issues worse. maybe if you use kevlar or such for all isolation ...
<wpwrak>
in any case, looks a like a very long journey into material science
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<DocScrutinizer05>
sure
<DocScrutinizer05>
you even could use ceaper thicker less flexible cable, starting maybe 10cm away from connector
<wpwrak>
yes, but that may create another potential problem spot
<wpwrak>
simplicity is usually best. let the economy of scale take care of "cheap" :)
<arielenter>
Hello every one I'm very interested on buying a nanonote but I was wondering if you could help me with a few questions
<arielenter>
Isn’t en.qi-hardware.com/wiki/Ben_NanoNote the official nanonote's site? It was working a few minutes ago but it seems is not any more for some reason.
<arielenter>
I wanted to know what was my best option, I live in Mazatlan Sin. Mexico and I'll be travelling to Los Angeles, could some one tell me were would it be better to have a nanonote be shipped? What page and place in the world should I order one from?
<arielenter>
Thank you.
<arielenter>
I used to remember that the page tuxbrain used to be an official distributor, but I tried to go to their page and it seems like the domain was bought by some one else. I remember reading an article about them selling a brand new device that I could connect to the nanonote to have it connected to a wifi, was it true? Can I get to buy one too? If the answer is no can I get a Ben WPAN?
<wpwrak>
not sure if the wiki sees much updating these days. i think it serves mainly as a place for static data
<wpwrak>
so you came to the right place :)
<arielenter>
wpwrak: Thank you
<wpwrak>
shops that are known to still have nanonotes are pulster.eu (few) and www.idasystems.net (more)
<arielenter>
wpwrak: Thanks again.
<wpwrak>
ben wpan ... would be atben, atusb, or both ? pulster has them. not sure how many. don't know if idasystems has any
<wpwrak>
i guess whether it's best to ship to the us or mexico would mainly depend on how nicely customs in mexico treat you
<wpwrak>
pulster is in germany and idasystems is in india, so for them it should be pretty much the same whether they send it to the us or to mx
<arielenter>
wpwrak: I see, thank you very much. By any chance do you know what happened to the tuxbrain page?
<arielenter>
I guess I could find a way to contact them. I think they were located on Spain or something, or perhaps Colombia since I think I remember reading some where that you could get a nanonote shipped form that country.
<wpwrak>
tuxbrain (the company) shut down a good while ago
<wpwrak>
don't remember when exactly ... maybe a year ago ?
<wpwrak>
also sharism.cc, which used to be the original (*) source of nanonotes, milkymist, etc., has gone off the map
<wpwrak>
(*) now a domain grabber has it
<arielenter>
About the device I think on remembering reading about on tuxbrain for wifi connection, I guess it doesn't exist does it?
<wpwrak>
oh, it does exist. but it's not wifi. it's IEEE 802.15.4.
<arielenter>
that's the Ben WPAN am I right?
<wpwrak>
yes. there's atben for the ben (goes into the memory card slow) and there's atusb for a (linux) pc
<wpwrak>
then the two can "talk"
<wpwrak>
alas, it seems that all qi-hw servers are down. so i can't show you pictures.
<DocScrutinizer05>
(#35) OOPS, I read that cursory, and now I see I missed the changed goal of this one
<wpwrak>
DocScrutinizer05: submit your hp25 solution. you'll probably win :)
<DocScrutinizer05>
it's for a different problem, called "xray" maybe
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<DocScrutinizer05>
you send in a beam and it gets deviated 90° when you hit a impority one-off. and it gets absorbed if you hit the imurity without offset
<DocScrutinizer05>
you see where beam comes out (if it does) when you send it in
<DocScrutinizer05>
kinda like minesweeper, just a tad more smart
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<DocScrutinizer05>
dang, lemme try it once with ALL the RIGHT letters in it: impurity
<wpwrak>
ah, so you'd even use fractional coordinates
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<wpwrak>
modern language is complicated. great Maxwell simply called it his "demon" :)