<whitequark>
but from posts it seems that this required a fair amount of twiddling with chemicals
<wpwrak>
i'm not surprised :)
<whitequark>
e.g. the concentration of NaCl in plating bath must be strictly between 0.05 and 0.08 NaCl equivalent mg/l
<whitequark>
s/mg/g/
<qi-bot>
whitequark meant: "e.g. the concentration of NaCl in plating bath must be strictly between 0.05 and 0.08 NaCl equivalent g/l"
<wpwrak>
hmm ......
<whitequark>
would be a bit tricky to get that precisely. I would need to get something better than my kitchen scales with 1g resolution
<whitequark>
deionized water is rather expensive to throw it around mindlessly
<wpwrak>
or just make at least 100 l at a time :)
<whitequark>
well, no, you can dilute it several times. homeopathy of sort :p
<wpwrak>
... and improve the process by adding details about degradation in long-term storage ;)
<whitequark>
oh, some of the guys report that solution is stable over 8 years
<wpwrak>
so you'd have to use 12 l per year. sounds feasible.
<DocScrutinizer05>
NaCl???
<DocScrutinizer05>
Graphite Aerosol - seems I mentioned that method a few days ago
<whitequark>
DocScrutinizer05: I think you didn't mention the aerosol part
<whitequark>
at least I imagined a process where one would manually put graphite on every hole. not pretty.
<DocScrutinizer05>
well, I was a tad unspecific, when I said "any conducting coating"
panda|z has quit [Remote host closed the connection]
panda|z has joined #qi-hardware
xiangfu has quit [Remote host closed the connection]
<wpwrak>
mix the graphite with some weak explosive. then detonate it in the hole and graphite will automatically coat the walls :0
<wpwrak>
#s/:0/:)/
<wpwrak>
like the exploding wire, but with proven russian graphite technology :)
panda|w530 has quit [Quit: Leaving]
jekhor has quit [Read error: Operation timed out]
<DocScrutinizer05>
you're giving me ideas again
<DocScrutinizer05>
:-)
<DocScrutinizer05>
not what you think :-P
<DocScrutinizer05>
you got a plate with holes and two conductive planes, each side one. It's easy to fill the holes with a substance that "shorts" the two planes, so you can make electric current flow through the substance. Should be useful for _something_ maybe
* DocScrutinizer05
idly thinks about alkaline batteries that - when leaking - allegedly can cover whole devices with some crystalline substance that grows like ... mildew
motley_ has joined #qi-hardware
<whitequark>
it totally does, I've had a "pleasure" to clean my usb keyboard from that shit recently
<whitequark>
had a few fun hours with sandpaper
<DocScrutinizer05>
is that stuff conductive maybe?
<whitequark>
I don't think so
<whitequark>
it's a crystallized salt
<whitequark>
NaCl isn't conductive when dry
motley has quit [Ping timeout: 265 seconds]
<DocScrutinizer05>
not even copper salts are conductive, and only few of then disassociate into gas and conducting copper at low temperature. yep, I know ;-)
<DocScrutinizer05>
them*
newcup has quit [Ping timeout: 265 seconds]
motley_ is now known as motley
<whitequark>
yeah
<DocScrutinizer05>
anyway when you fill a hole in a PCB with some conductive goo or putty (or porridge) and then send current through it from the two copper planes, the current density is magnitudes higher at the edges of the hole inside the goo than anywhere else
<DocScrutinizer05>
basically theoretically you even could use something loosely reminding to electromigration in such setup
<DocScrutinizer05>
a problem is "race"
<DocScrutinizer05>
the process has a positive feedback and even stops as soon as one single sub-process finished, effectively defeating multiple sub-processes to complete
<DocScrutinizer05>
incandescent bulds have same problem. You're using metal-halogenid gas to turn the positive feedback (thinnest part of wire heats up most and thus evaporates fastest) into a negative one - well, almost
<DocScrutinizer05>
s/buld/bulb/
<qi-bot>
DocScrutinizer05 meant: "incandescent bulbs have same problem. You're using metal-halogenid gas to turn the positive feedback (thinnest part of wire heats up most and thus evaporates fastest) into a negative one - well, almost"
<whitequark>
well, that's why I don't fill holes with good
<whitequark>
*goo
<whitequark>
I rather cover the internal surface of hole with it
<whitequark>
I've seen a process where you cover PCB with conductive ink and then use compressed air to blow it out
<whitequark>
or a vacuum cleaner
<DocScrutinizer05>
btw that's the reason why you shouldn't dim halogen incandescent lamps too much. the halogen-metal will not dissociate anymore
<DocScrutinizer05>
sounds reasonable
motley has quit [Changing host]
motley has joined #qi-hardware
pcercuei has joined #qi-hardware
<wpwrak>
hehe, just saw that putin is among the peace nobel prize nominees this year :) maybe that ukraine thing is just to boost his chances :)
<whitequark>
what
zhai has joined #qi-hardware
<whitequark>
>Over time many individuals have become known as "Nobel Peace Prize Nominees", but this designation has no official standing.
<wpwrak>
well yes, but one of them will get it, right ?
<larsc>
well hitler was nominated as well
<larsc>
(as a joke though)
<pcercuei>
Hitler didn't do only bad things, he's the guy who killed Hitler after all
<pcercuei>
though he also killed his assassin
<DocScrutinizer05>
OMG
<wpwrak>
so he's a martyr as well
<DocScrutinizer05>
you were even able to top first post
<DocScrutinizer05>
:-)
* wpwrak
bows
<wpwrak>
a while ago, one politician made headline news around here with the following statement: "¡Hitler era un tipo espectacular! ¡Era muy importante en el mundo!” ("Hitler was a spectacular guy ! He was very important in the world !")
<wpwrak>
somewhat surprisingly, he got away with it, though with some scorch marks
<wpwrak>
technical challenge of the day: goal: place pogo pins exactly vertically. the problem:: tactile feedback doesn't really help you, i.e., you don't feel a difference between them merely touching the pcb or touching it with their entire base
<wpwrak>
this is for soldering, so you can't grab them directly but go through tweezers, which may contribute to the weak feedback
<whitequark>
wpwrak: use 2 drilled plates for guiding them
<whitequark>
maybe 1 ~5mm thick plate
<wpwrak>
that could easily get in the way of soldering
<whitequark>
oh? why?
<wpwrak>
so any guide would have to be localized, either small, or limited by angle
<whitequark>
what exactly are you trying to do?
<wpwrak>
also, you must be able to apply some pressure. so just something that grabs it on the side won't be enough
<wpwrak>
solder pogo pins
<whitequark>
well... you have throughholes right?
<wpwrak>
doens't help :-(
<wpwrak>
i thought it would, but no, it doesn't
<whitequark>
nono. see, you stick pogopins through drilled guide plate, then place pcb exactly on top and stick end of pogo pin through pcb
<whitequark>
then solder it
<whitequark>
should be perfect
sharek has joined #qi-hardware
<DocScrutinizer05>
yep
<wpwrak>
ah, they're too short for proper soldering at the bottom. have to be soldered from the top
<DocScrutinizer05>
o.O
<wpwrak>
i didn't make them ...
<DocScrutinizer05>
you have a problem
<whitequark>
photo maybe?
wej has quit [Ping timeout: 252 seconds]
<wpwrak>
i was thinking of the following approach: take a piece of wood and make a hole roughly the diameter of the lower "pipe", so that it will fit snugly
<DocScrutinizer05>
only idea I could come up with: glue
<wpwrak>
that would could be used for holding the pin while soldering. the problem: it would still "float"
<DocScrutinizer05>
err, didn't you just reject that approach?
wej has joined #qi-hardware
<wpwrak>
it would be small and end some mm above the base, giving room to reach in with the iron
<DocScrutinizer05>
so what's the problem then?
<wpwrak>
keeping it exactly vertical
<DocScrutinizer05>
now you lost me too
<wpwrak>
so one way to do that would be to put a pcb with an acceleration sensor on top of it, and use that to detect the orientation and to indicate when the pcb is level (and thus the wooden cylinder glues to its bottom would be vertical)
<wpwrak>
the pogo pin needs to be placed vertical with respect to the pcb. let's assume i have a sufficiently level table that the pcb lies completely flat
<DocScrutinizer05>
get a wood 6mm*30mm*100mm, drill as many (deadend) holes as needed into the 6*100 surface
<DocScrutinizer05>
when really needed, add contraption to keep that wood level to PCB
<DocScrutinizer05>
T
<wpwrak>
ah, you'd make the "cylinder" long, like a pencil. yes, who not
<wpwrak>
#s/who/why/
<wpwrak>
that would also work with the sensor approach. and may even be accurate enough with just dead reckoning. thought that's oddly imprecise for this sort of task, probably because you can only see inclination in one plane at a time
<wpwrak>
that's also the problem with drilling vertically without a drill stand. you think you're perfectly positioned but then you find you've been way off ...
<DocScrutinizer05>
or, very straight forward prgmatic: grip the pogopin like a mill in your CNC, make CNC insert it into PCB hole, solder
<wpwrak>
argh ;-)
<whitequark>
actually a good idea
<wpwrak>
with your BIG mill, perhaps
<whitequark>
big? mine is 30x20. BIG one is 70kg 60x40 model
<DocScrutinizer05>
for the wood approach: when you get a L-shaped wood with short end 100mm and long end 200mm and you drill the pogp holes to the open end of short part, you have a hard time holding that *not* parallel to the PCB
<wpwrak>
hmm, not sure about that. the basic problem remains that you only see one axis/plane
<DocScrutinizer05>
wtf?
<whitequark>
wpwrak: just drill it with CNC
<whitequark>
it will be vertical the
<whitequark>
*then
<DocScrutinizer05>
are you able to keep the long end of a 200*400mm object in <20mm proximity to your table's surface?
<DocScrutinizer05>
if yes then you don't need to see *anything*
<DocScrutinizer05>
I leave it up to you to calculate the sin() and cosin() etc for 400mm vs (20mm * 10%)
<wpwrak>
you could tilt the L also along the long axis
<DocScrutinizer05>
yes, when you ponder long enough how to act like an idiot to do that, you can
<whitequark>
lol
<DocScrutinizer05>
an object in a plane that touches amother plane in 3 point is defined in relation to that other plane
<DocScrutinizer05>
one point is your pogopins, you might actually be able to find a way to make 2 more contact points between L and your table
<wpwrak>
yes, you could make a "bridge". but then you need to match heights. not quite trivial, need space, and will change with tool wear
<DocScrutinizer05>
you know, 3-leged stool doesn't wiggle
<wpwrak>
exactly. but the distance between legs would be very small since the pcb isn't large
<DocScrutinizer05>
again: I leave it up to you to calculate the sin() and cosin() etc for 400mm vs (20mm * 10%)
* DocScrutinizer05
headdesks
<wpwrak>
for 400 mm, i would to add whatever the pcb is mounted on as well. this makes the system even more complex.
<DocScrutinizer05>
isn't the pcb flush on your pretty large table?
<wpwrak>
no, not necessarily
<DocScrutinizer05>
meh, I'm out
<wpwrak>
it's level with what support structure i use, though. and that one is flat on the table.
<DocScrutinizer05>
try segway technology!
<wpwrak>
;-))
<DocScrutinizer05>
silly
<DocScrutinizer05>
btw the pogopin itself for sure isn't precise enough to try and make it sit in PCB exactly perpendicular, based on the rim at bottom alone
<wpwrak>
dunno. it would seem that this ought to work if feedback was better
<DocScrutinizer05>
never will
<wpwrak>
i mean, you can usually feel if something makes proper contact or not. and the solder it liquid at that time, so the pad is very level
<DocScrutinizer05>
starts with pogopin rim not absolutely plane and perpendicular to pin's long axis
<DocScrutinizer05>
then continues with the hole you drilled into PCB and the gaps and edge rounding you have there
<DocScrutinizer05>
but sure, it's definitely way more exact plane to surface of PCB than PCB surface is plane to table it sits on¡
<DocScrutinizer05>
after all there culd be a grain of dust under one corner of the PCB and lift it from table
<DocScrutinizer05>
and then the wood, OMG! that might even deform with air humidity. Yu'll need to use massive platinium
<DocScrutinizer05>
do those pogopins adjust the laser targeting at the moon and there particularly to the reflector the Apollo astronauts placed there? Or why do they need that precision?
<DocScrutinizer05>
is soldering end the thick or thin one?
<wpwrak>
maybe what i should try first is just a piece of wood to get a firmer grip (compared to tweezers, which add at least one degree of freedom on their own). maybe that'll be enough already.
<wpwrak>
soldering is at the base where the thin through-hole pin emerges
<DocScrutinizer05>
and that fsckng through hole pin is too short to get soldered from other side of PCB? :-o
<wpwrak>
yeah, pcb is 1.6 mm, pin is nominally 1.75 mm. it's barely visible
<DocScrutinizer05>
wtf?
<DocScrutinizer05>
honestly, glue that shit into place before soldering
<wpwrak>
;-)
<DocScrutinizer05>
or make sure your PCB hole fits snuggly
<DocScrutinizer05>
worst case a pair of pliers slightly flattening the thru hole pin can do wonders
<wpwrak>
yeah, that could be an option. they specify a fairly large (minimum) tolerance
<wpwrak>
eek
<wpwrak>
i think by the time it deforms, you've already torn it off :)
jekhor has joined #qi-hardware
<DocScrutinizer05>
tear off a wire by applying force perpendicular to its axis, from both sides? how does that happen?
<DocScrutinizer05>
I've flattened wires from o to I that way, but never ever torn one off
<DocScrutinizer05>
unless I used wire cutter instead of flat pliers
<DocScrutinizer05>
;-)
<DocScrutinizer05>
when piers are too weak, I sometimes use a hammer
<DocScrutinizer05>
pliers*
<DocScrutinizer05>
or if you're really worried, rather apply some leadfree solder to surface of wire. Just so much that it sits in your PCB hole tightly
<DocScrutinizer05>
though I consider the mechanical flattening of a 0.3mm in middle of those 1.75mm wire the better option
<DocScrutinizer05>
usually you have suqare-shaped nails instead of round wire for such purposes, on thru hole components
<DocScrutinizer05>
and the diagonale of the square is a few tens os a mm wider than the hole you drill to the PCB
<sharek>
whitequark: remember my question of yesterday ? (disable poweroff screen) ? I found the answer... is easy! setter -blank 0 > /dev/tty0
<sharek>
thanks for the tip, you are in the right way for solve them!
<DocScrutinizer05>
s/os a /of a
<qi-bot>
DocScrutinizer05 meant: "and the diagonale of the square is a few tens of amm wider than the hole you drill to the PCB"
<DocScrutinizer05>
makes for a nice press fit
<DocScrutinizer05>
square shape isn't mandatory though. Just make sure that your wire has a different shape than your hole, with one dimension slightly larger than hole diameter
<DocScrutinizer05>
heck, you even could cut a thread on the wire ;-P - then screw it into the PCB
<DocScrutinizer05>
when your PCB is through hole, you could as well consider spot-welding, with high current. I'd rather test that on a few scrap samples though ;-)
motley is now known as motley_
motley_ is now known as motley
<DocScrutinizer05>
apropos wire cutter - you know those isolation stripper pliers with the two V-shaped blade claws and the screw to adjust how far they close. Ideal to make some dents into the wire without cutting it (or tearing it off). You just need careful adjustment of the screw
<DocScrutinizer05>
when adjusted correctly (and actually not too short wire to pass the front blade thickness) this thing will make almost perfect 4 teeth to your wire, that hold the wire perfectly in a hole of matching diameter
zhai has quit [Ping timeout: 252 seconds]
rz2k has joined #qi-hardware
kristian1aul has quit [Remote host closed the connection]
sharek has quit [Quit: sharek]
kristianpaul has joined #qi-hardware
arielenter has joined #qi-hardware
pcercuei has quit [Ping timeout: 252 seconds]
dos1 has joined #qi-hardware
<whitequark>
bogopins
<wpwrak>
hmm, i'd rather refrain from abusing these little pins. they're not that fat after all.
<wpwrak>
they're almost perversely good. better than anything else i tried
<wpwrak>
already at pro'skit there are a number of variants of the theme. PK-3001, 1PK-3001E, 8PK-3001D, maybe more. they look a little different but all do the same
<wpwrak>
naw. i have that kind, too. but it's no comparison
rz2k has quit []
<wpwrak>
mine has a flat blade, so it's very convenient for UBB cables (small ribbon) ;-) but for individual wires, i just use the simple ones
pcercuei has joined #qi-hardware
<DocScrutinizer05>
everybody has his favorites
<DocScrutinizer05>
had that flat cable straight blade thing too, and fiund it not to the point since you don't need stripped flat cable where the single wire attaches to other wires so distance between the wire strands is raster of the flat cable
<DocScrutinizer05>
also had that tool you favor and found it quite inconvenient to use
<DocScrutinizer05>
when I actually want to solder a flat ribbon cable to a number of solder points in raster distance, I use the effect of plastic retracting 0.5mm on heating it
<DocScrutinizer05>
also you can poush the isolation a 1mm or so *before* you cut the flat cable. After cutting the isolation will retract to original position slowly, exposing a 0.5mm to 1mm of blank copper wires
<wpwrak>
(flat cable) hmm, for UBB (or any case where the PCB pattern matches the cable) the raster is just fine ... obviously, because it's designed for it :)
<wpwrak>
(push) you mean pull/stretch. yeah, that sounds nice. i wouldn't count on plastic retracting with heat, though. it will, but it can get messy, too, with molten/burnign plastic where you don't want it
<DocScrutinizer05>
ok, when you often have that usecase then the stright blade tool is obviously useful
<wpwrak>
i keep it around just for that ;-)
jekhor has quit [Read error: Connection reset by peer]
jekhor has joined #qi-hardware
jekhor has quit [Ping timeout: 240 seconds]
supermanw has joined #qi-hardware
arielenter1 has joined #qi-hardware
arielenter has quit [Read error: No route to host]
arielenter1 has quit [Ping timeout: 240 seconds]
arielenter has joined #qi-hardware
jekhor has joined #qi-hardware
supermanw has quit [Remote host closed the connection]
rz2k has joined #qi-hardware
inkeep has joined #qi-hardware
arielenter has quit [Ping timeout: 244 seconds]
wej has quit [Ping timeout: 245 seconds]
arielenter has joined #qi-hardware
wej has joined #qi-hardware
inkeep has quit [Ping timeout: 269 seconds]
idundidit has quit [Ping timeout: 240 seconds]
idundidit has joined #qi-hardware
arielenter has quit [Read error: Connection reset by peer]