#qi-hardware IRC log for Sunday, 2014-02-23

whitequarkwpwrak: can you check whether my idea is sane or not?04:03
whitequarkso here it goes: I've found out that my machine apparently misses some steps, because it's not as accurate in repeat positioning as I wish04:03
whitequarkhowever, how exactly does one measure whether it's off 0.05mm by x or y axis?04:04
whitequarkit's not like I can place a ruler and read it04:04
whitequarkso the idea is, I should get a conical cutter, with as thin end as possible, and then engrave a vernier scale04:05
whitequarkassuming it is accurate with (slow) feeds and inaccurate with rapids, that should allow me to measure the runoff very precisely at a negligible cost04:06
whitequarkhttp://lab.whitequark.org/notes/2014-02-22/on-concentration-of-etchant/06:20
whitequarkspecifically http://lab.whitequark.org/images/etching/2014-02-22/etched.jpeg06:20
whitequarkwpwrak was right, 100µm is fine but 50µm really isn't06:20
whitequark(it detaches while etching, and in addition seems to be edge-etched)06:21
whitequarkthough... that's not really 100µm. all other traces are roughly the right size, but 100µm got butchered by the printer again.06:24
whitequarkit's actually 150µm, same as the trace below it.06:24
shevekwhitequark: What sort of machine are you talking about?  A cnc mill?  Do you have full control over the firmware?06:51
shevekWhat I did on my 3-D printer to detect missing steps, is to go somewhere to the middle of the axis; move a piece at a high speed to test, then move back to the limit switch and see if it still is in the position where I left it from.  If not, I missed steps.06:52
whitequarkshevek: a CNC router (spindle moves rather than table), and I use EMC206:54
whitequarkwell, I'm already sure I do have missing steps. I want to know how much exactly and I want to have a way to reliably check for their presence in order to determine the optimal feedrate06:55
shevekYes, that's what my method was meant for.06:55
whitequarkhm, how did you determine 'if it's still in the position where you left it from' ?06:55
shevekWhen going at low speed to the limit switch, it very reliably is always in the same position.06:56
whitequarkohh, limit switches. don't have any here.06:56
shevekAh, then it won't work.06:56
whitequarkbut I could very well mount one.06:56
shevekHow do you home without one?  Just bump into the wall for a while?06:56
whitequarknah, that would likely damage the ballscrew if done a lot06:57
shevekYes, but how else can you do it without a limit switch?06:57
whitequarkI just jogged it manually to, roughly, (0.5, 0.5, 0.5) and made it my pivot06:57
shevekOr do you manually position it before each job?06:57
whitequarkthen each time before turning it off, I tell it to go back to origin06:58
whitequarkso I won't have to jog it again06:58
shevekAh yes.06:58
shevekDoes that work well enough for Z though?  I would expect that to require high accuracy.06:58
whitequarkI have to set Z coordinate system for each workpiece, otherwise it can be off about ±0.5mm06:59
shevekBecause of variations in pcb thickness?06:59
whitequarkthis is what annoys me; each rapid in Z throws accuracy out of the window06:59
whitequarkno, due to missing steps. PCBs are really flat, and while it's mounted not perfectly horizontally on the table, that's within ±0.1mm, I'd say07:00
shevekOh; missing steps should be avoidable, I would think.07:00
whitequarksame thought here07:00
whitequarkI set it up from the accompanying "documentation", so in theory the values should work07:00
whitequarkI can see my power supply not providing enough peak current for steppers, or the values just being wrong.07:01
shevekIf you have stepper driver controllers with a current adjustment, turning that up may help as well.  But I would just make it go slower.07:02
whitequarkmine are TB6560AHQ07:02
whitequarkcnczone.com almost unanimously considers those crap07:03
whitequarkhm, seems to have a bunch of configuration pins. excitation mode, current decay, torque setting07:04
whitequarkshevek: any of that ringing a bell?07:04
shevekIt didn't, I'm just looking at the datasheet now.07:05
shevekThe pin I'm talking about is 1 and 2 (TQ2 and TQ1).  Looks like it's a digital setting though; you probably already have both low, which just gives maximum torque.07:07
shevekAh, but wait; there's an analog reference resistor on NFA/NFB.07:08
shevekIOUT (A) = 0.5 (V) / RNF (©)07:08
shevekIf you have a potmeter there, you can change the value to whatever is best for your system.07:09
shevekThere must be some resistor already, otherwise it wouldn't work.07:10
whitequarkhmmm07:11
whitequarkI didn't yet trace the whole board...07:11
whitequarkseems like they're pulled down indeed07:13
whitequarkresistor seems to be 510 ohm07:15
whitequarkno, that can't be right07:16
whitequark0.510 ohm07:16
shevekWhy not?  That would set the current to about 1A; that sounds reasonable.07:16
whitequark0.5 / 510 = 0.5 mA07:17
whitequarkwhereas 0.510 is right one07:17
shevekYes. :-)07:17
whitequarkso... my adjustable PSU says all three steppers at max speed consume about 2A07:17
whitequarkwhich is weird, but in the same ballpark07:17
wpwrakwhitequark: i think the net split ate my comment about missed steps ... here we go again:09:57
wpwraksounds overly complicated. if you have a "good" and a "bad" mode, just go back and forth enough times. "good" in one direction, "bad" in the other. eventually, the missed steps will add up09:57
wpwrakyou can of course also use a ruler :) like this: go to (0, 0). then go to (max, 0), engrave a little line in y+ direction, then go back to (0, 0). then to (max, step), engrave another one in y+, then (0, 0) and (max, 2*step), and so on09:58
wpwrakwith time, you should have a line of "dashes" should then be easy to check with a ruler whether it veers off09:58
whitequarkwpwrak: ohhh, you're entirely right09:58
whitequarkshould be even possible to write that entirely in gcode09:59
whitequarkparametric gcode is the best idea ever. I wonder if it's possible to export from a parametric CAD to parametric gcode10:01
wpwrak;-))10:01
whitequarkof course it's not if the CAD uses something like a SAT-solver10:01
whitequarklike freecad10:01
whitequarkdoes fped have a solver?10:01
wpwrakfped doesn't need one - all calculations are "procedural"10:02
whitequarkso it's possible to make that with fped10:02
wpwrakit does hunt around for variables a bit, though. so you have dynamic scoping instead of static scoping.10:02
whitequarkyou could resolve it at export time10:02
whitequarkI mean, you won't add any new variables or elements *after* gcode export, just vary parameters10:03
whitequarkand variable resolution isn't dependent on that10:03
wpwrakyup, you could turn each variable into <frame>_<var-name>10:03
whitequarkby the way, I now think it's possible to make an USB-LPT adapter for CNC10:03
whitequarkthat is, without embedding a full interpreter or any really clever stuff for that matter10:03
whitequarkthe thing is, CNC contol software doesn't really use LPT interactively, or at least at level where USB latency becomes significant10:05
wpwrakare delays between writes constant ?10:05
whitequarkonly thing it needs is precise waveform generation. you can simply ensure you always have, say, a second of them buffered, and then refill the USB dongle via bulk transfers10:05
whitequarkit doesn't really matter too10:06
whitequarkit's absolutely OK if the dongle slightly "lags" behind the actual control software--there's pretty much no realtime feedback10:07
wpwrakhmm, you could basically generate your own timing. so the dongle would have to know max speed, acceleration, and so on10:08
whitequarkno, the whole idea is to avoid putting *any* EMC2 logic in dongle10:08
whitequarksince that's means I'm making a poor clone of EMC2, which I'd like to avoid10:09
whitequarkthe only inputs EMC2 knows are... home/limit switches, emergency stop, spindle phase (for speed measurement)10:09
wpwrakso the timing resolution is much more coarse than 1 ms ?10:09
whitequarkwpwrak: no, it's much finer10:09
wpwrakso usb will lose the timing information10:10
wpwrakand you have to reconstruct it somehow10:10
whitequarkI want emc2 to generate a waveform; timing+levels chart. then transmit that chart to dongle.10:11
wpwrakah, you want to tweak the format. i see.10:11
wpwrakyes, that could of course be done.10:11
whitequarkthe important point is, there's no requirement to reproduce that chart *immediately*. the only requirement is to reproduce it *accurately*10:11
wpwrakof course. you could even pass handling of the switches to the dongle10:12
whitequarkESTOP and spindle phase inputs won't suffer too from several (dozen) ms of delay10:12
whitequarkswitches... it may be more complicated. I never actually used them in EMC2 so I wouldn't know the requirements10:12
wpwrakwhile (!SWITCH) STEP;10:12
whitequarknah, that ignores deceleration profile10:13
whitequarkwould mean missed steps.10:13
wpwrakif it's just for finding (0, 0), that's about what you'd want, no ?10:13
whitequarkignoring deceleration profile would mean arriving at home quickly and slowly would actually set it to different positions10:13
whitequarkI mean, deceleration profile is there to combat machine inertia10:14
whitequarkand see above, I don't want to duplicate EMC2 logic in dongle10:14
wpwrakso (0, 0) is not a real limit. well, you could extend this. while (!SWITCH) STEP; DECELERATE;10:14
whitequarkalready answered :p10:14
wpwrakSTEP and DECELERATE would be waveforms :)10:15
whitequarkthat implies EMC2 would need to stop treating dongle as "weird LPT port" and actually know to which waveforms to upload there10:15
whitequarkso, much more fundamental changes to EMC2. don't like that.10:15
whitequarkI don't even want dongle to know what it controls. I want it to be kind of10:16
whitequarklogic analyzer in reverse10:16
wpwrakwith this simple algorithm, you'd have to run X and Y separately. doing X and Y in parallel would be a little more complicated. i.e., you'd need two concurrent "channels"10:16
wpwrakwell, the "weird lpr" kinda disappears when you send (t, pattern) tuples instead of just patterns :)10:16
whitequark(t, pattern) tuples still require insignificant changes to EMC2 backend10:17
wpwrakand your 1 s buffer is far too large for properly responding to a switch10:17
wpwrakso you have to cut that loop10:17
whitequarkI mean, I'm sure EMC2 internally just generates those tuples10:17
whitequark(too large) yep. that's what I'm sad about.10:17
wpwrakseems plausible10:17
whitequarkpossible solution: tell EMC to find home at relatively low speed10:18
whitequarkthen cut the step waveform ignoring deceleration profile10:18
whitequarkanother possible solution, dependent on how exactly EMC is built: ask EMC for tuples in "advance", so I could send data for t+1s while EMC still thinks it's t c10:19
whitequark*t s10:19
whitequarkthen I could poll switches at, say, 1000Hz, typical USB interrupt freq10:20
whitequarkthat ought to be enough10:20
whitequarkit all hinges on whether EMC is able to give me waveform for t+1s while receiving input for ts10:20
whitequarkbuut if that works, I really like it. very simple dongle, no LPT or rt kernel needed, works with existing proven gcode interpreter10:21
whitequarkDocScrutinizer51: ^ relevant to your interests10:22
wpwrakwave(t+1s) where wave(x) is a function of wave(t_switch) would require clairvoyance. if it can do that, it may just send the right profile to come to a precise stop at (0, 0) ;-)10:23
DocScrutinizer05whitequark: eek, how many lines back?10:25
wpwrakall of them :)10:27
whitequarkDocScrutinizer05: about 40 minutes10:27
whitequark30 even10:28
DocScrutinizer051: (( just go back and forth enough times.)) sorry, doesn't work this way. "back & forth" would mean steep ramp-up and slow ramp-down in positive direction, while slow ram-up and steep ramp-down in the other direction. Otherwise the error compensates, no matter how many km you run forth & back10:31
whitequarkDocScrutinizer05: if it compensated, I wouldn't be having any problems! I specifically notice error when I do feed down (plunge into material), then rapid up, move, and feed down again -- which makes a hole in the table because Z missed steps10:32
whitequarkramp up and down for any single coordinated movement are identical10:33
wpwrakDocScrutinizer05: i mean slow & safe on one direction, fast and jumpy in the other. any skipped step, no matter in which phase of the movement, would therefore add up in the same direction10:33
whitequark^10:33
wpwrakah, so the problem is mainly Z, not X/Y ?10:34
whitequarkwell, on Z it's immediately problematic because poor table. I *think* it would manifest itself on X/Y, because on X/Y settings allow it to travel even faster10:35
whitequarkbut I have not specifically noticed it on X/Y yet10:36
wpwrakwell, you could run the aforementioned test for X/Y10:38
whitequarksure10:39
DocScrutinizer05wpwrak: no it won't10:40
DocScrutinizer05missed steps are during ramp-up. During ramp-down you see bogus additional steps10:41
wpwrakfor Z, you can do the same. you can test height very easily by placing some object on the table, moving the head over it, lowering the bit manually until it touches, lift off and move elsewhere, do the fast up / slow down ritual, then come back and see if you're still at the same height10:41
whitequarkDocScrutinizer05: you sure it's ramp-up and not linear motion?10:42
wpwrakah, if bogus steps get inserted, then that wouldn't work. but are they ?10:42
DocScrutinizer05I guess it simply is missing steps on move up due to much higher load (force)10:42
whitequarkyes, exactly my thoughts10:42
wpwraki concur10:42
DocScrutinizer05and of course it could add steps particularly when motor gets "pushed", when moving down10:43
DocScrutinizer05depends on your gear10:43
whitequarkright, it seems to creep downwards10:43
DocScrutinizer05as a rule of thumb: when you apply AC to the stepper, it should run relatively free. When it starts moving then, you have a problem with force pushing motor10:44
DocScrutinizer05but I guess you have a threat spindle, and that isn't known to feed back forward force to motor10:45
whitequarkthreat spindle ?10:46
DocScrutinizer05basically a long screw10:46
whitequarkballscrew, yes10:46
DocScrutinizer05thread, I guess10:46
DocScrutinizer05coffee deficit10:47
wpwraka threatening spindle, its weight exceeding the crush force of your skull :)10:48
DocScrutinizer05reduce your Z-speed particularly up10:48
DocScrutinizer05increase voltage to motor10:48
DocScrutinizer05change coil config on 6/8-wire stepper10:49
whitequark4-wire10:49
DocScrutinizer05:nod:10:49
DocScrutinizer05thought as much10:49
whitequarkvoltage, hmm... it's 6 volts below driver IC limit10:49
whitequarkgiven my previous, ahem, experience with AMRs on this CNC, I'd rather not check whether they are manufactured to spec :S10:50
wpwrakvoltage is at the designed level ? or below that, too ?10:52
whitequarkfrom factory the voltage was at 24V10:53
whitequarkI'm currently driving them with 29V because I need same PSU for steppers and spindle10:53
whitequarkdriver IC AMR is 36V10:53
DocScrutinizer05you seen last c't hacks issue already?10:54
wpwrakhmm, i wonder what +20% voltage does to a stepper ...10:55
whitequarknot entirely10:55
wpwrak(with identical timing)10:55
whitequarkwpwrak: they're not rated to voltage. rather to current10:55
wpwrakso the driver regulates the current ?10:56
whitequarkyep10:56
whitequarkcurrently it's set up to drive them at roughly 1A, though my PSU reports lower values10:56
DocScrutinizer05sure, since that's maximum current.10:56
DocScrutinizer05limit10:56
wpwrakdid you have to change the "programming" resistor ? they're sometimes a function of the supply voltage.10:56
DocScrutinizer05the true current is a function of voltage/speed10:57
whitequarkwpwrak: from the datasheet it appears that the driver regulates current regardless of supply voltage10:57
whitequarksince it's not in equation10:57
wpwrakgood10:57
DocScrutinizer05the higher the stepping speed, the lower the current10:57
nicksydneywpwrak: normally what footprint you use for Balun ?10:57
wpwrakoh, another thing: you can detect table contact by mounting a needle on the head, grounding the table, and running a wire from needle to a suitable input10:58
wpwrakif the table isn't isolated, add battery + opto-coupler10:58
whitequarkwpwrak: already thought of it, the CNC even has a suitable probe input10:58
whitequarkI only need to run another two wires and change EMC config to make that work10:58
whitequarkhowever I couldn't use that for "production" work, because I can't reliably insert tool to a predefined depth10:59
whitequarkthe collet can't do that10:59
DocScrutinizer05tools are conductive too11:00
whitequarkDocScrutinizer05: right11:00
whitequarkbut there's another my concern, what if the contact is broken somehow? EMC is going to run tool into workpiece11:01
wpwrak(depth) the idea is to use this for determining the tools' Z position :)11:01
whitequarkwpwrak: meaning: I can't set coordinate system based on readings off a needle and then change that to a tool11:01
whitequarkbecause I can't ensure tool has well-known stickout11:01
wpwrakraise the contact. then you can just stop if you must have missed it11:02
wpwrakwell, for adjusting tools, you'd use the tool itself, instead of a needle11:02
wpwraklike DocScrutinizer05 said11:02
DocScrutinizer05make the "table2 the conductive lever of a microswitch11:02
whitequarkhmmm11:03
DocScrutinizer05when switch operates then you got a problem11:03
wpwrakif you just want to debug your motor, use a needle since if anything goes wrong, it can't do much damage11:03
whitequarkwpwrak: yeah, for debugging I'd probably do that11:03
whitequarkanother thought, how to ensure electrical contact between moving parts at 20000rpm11:04
whitequarkI've checked and I can connect to the tool from any exposed part of axis assembly (but not motor case)11:05
wpwrakyou may also be able to test your connections: for each, have two signals. then check for connectivity between A1-A2 and B1-B2, before checking A-B11:05
whitequarknot sure I follow11:05
DocScrutinizer05you don't calibrate with spindle running o.O11:06
wpwrakif you're worried one cable may get disconnected, have two cables and test whether they're connected to each other11:06
whitequarkDocScrutinizer05: hm, I thought of making some kind of permanent mod11:06
DocScrutinizer05so what?11:06
DocScrutinizer05can't you control your spindle?11:06
whitequarkso that CNC wouldn't need by attention each time it needs to probe something11:07
whitequarkI can11:07
whitequarkbut to be permanent, it needs to always be connected to tool/axis11:07
DocScrutinizer05no, only when not spinning11:07
whitequarkhm... add some mechanical contraption to make contact before it needs measurement?11:07
wpwrakyou could have a lateral pogo pin to connect to the head. that way, there would be no permanent connection there11:08
whitequarkwpwrak: ooooh, pogo pin, an excellent idea. I even have a bunch11:08
wpwrak(nuhc) good. since you'll want two of them :)11:08
wpwrak#s/nuhc/bunch/11:09
DocScrutinizer05wow, what a typo11:09
DocScrutinizer05cat?11:09
DocScrutinizer05;)11:09
whitequarkokay, idea: spindle (at the bottom) has this spinning plastic thingy with axis end exposed11:10
whitequarkhttp://imgur.com/22A4LGi11:10
DocScrutinizer05UGH what's that?11:11
whitequarkI could make a fixture, place it on the stepper near, and place both pogo pins for contact and IR LED/transistor for speed measurement11:11
whitequarkDocScrutinizer05: it's apparently some kind of cooling fan11:11
DocScrutinizer05mhm11:11
wpwrakDocScrutinizer05: lack of morning caffeine after being rudely awakened by a gnat11:11
DocScrutinizer05I guess the axis is straight to other side11:11
whitequarkactually no, it's not11:11
DocScrutinizer05gnat?11:12
whitequarkit's just a plastic handle for you to spin the axis manually, I think11:12
whitequarklike that handle on a stepper nearly11:12
DocScrutinizer05ooh11:12
DocScrutinizer05ding lnows gnat11:12
DocScrutinizer05knows11:12
DocScrutinizer05ok, that's absolutely fine to place ONE pogo in center11:13
DocScrutinizer05absolutely in center11:13
DocScrutinizer05ang give it some graphite11:13
DocScrutinizer05or find a ball bearing, they make fine contact to moving parts11:14
DocScrutinizer05the motor shall have at least two of them11:14
whitequarknot exposed11:15
DocScrutinizer05indirectly exposed11:15
DocScrutinizer05the ball bearings are mounted to motor's steel case11:15
whitequarktold you: there's no contact between axis and case11:16
DocScrutinizer05you can't tell me your spindle axis is partially hold by plastic contraptions11:16
whitequarkthat was the first thing I checked11:16
whitequarkthe plastic contraption above has no structural function11:16
whitequarkI dunno what's inside motor11:17
DocScrutinizer05now that's extremely weird then11:17
DocScrutinizer05go for the pogopin11:17
whitequarkright11:18
DocScrutinizer05check if at least axis is a conductor along full length ;-)11:18
whitequarkverified that, it is11:18
DocScrutinizer05I've actually seen industrial designs that did exactly this for grounding of motor axis (in tape recorder for example)11:19
whitequarkpogo?11:19
DocScrutinizer05yep11:19
whitequarkcool11:19
DocScrutinizer05spring lever with a coal11:19
DocScrutinizer05or brass on steel11:19
DocScrutinizer05brass+steel combo needs no lubrification11:20
whitequarkaxis looks like steel for sure11:20
whitequarkdunno what pogo pins are made of11:20
DocScrutinizer05gold?11:20
whitequarkno11:20
DocScrutinizer05;-D11:20
whitequarkhttps://www.sparkfun.com/products/917411:21
DocScrutinizer05no?11:21
DocScrutinizer05eeek, the extral long weapon11:21
DocScrutinizer05don't use that one, it will give you a lot of headache11:22
whitequarkoh?11:22
DocScrutinizer05you can't use it to point at a spinning axis' center11:23
DocScrutinizer05it will move avay in no time11:23
whitequarkhm11:23
DocScrutinizer05use a brass spring, like a hand of clock11:23
whitequarkhand of clock?11:24
DocScrutinizer05L11:24
whitequarknot sure I follow11:24
DocScrutinizer05short thing: axis. Long thing: lever11:24
DocScrutinizer05I _11:24
DocScrutinizer05/_11:25
DocScrutinizer05\_11:25
whitequarkI think I get it11:25
DocScrutinizer05(side view)11:26
DocScrutinizer05|_[motor]____<toolbit>11:26
DocScrutinizer05you might use a contact spring from a slaughtered relay11:27
DocScrutinizer05(though that usually isn't brass)11:27
DocScrutinizer05well, sometimes it actually is11:28
DocScrutinizer05phosphor brass11:28
DocScrutinizer05hey, how about mounting an optical mouse against arbitrary flat moving_up/down surface of your spindle unit?11:31
DocScrutinizer051200dpi resolution? sounds fine11:31
DocScrutinizer05a decent mouse also shouldn't 'lose steps'11:31
DocScrutinizer05sure no absolute value ;-) only relative. But then, so what?11:32
DocScrutinizer05if you had a GTA04-jr-edition, this would be integrated in a convenient way on left small side, to mount the whole thing to CNC and directly read Z coord from display ;-D11:33
whitequarkhm11:37
DocScrutinizer05http://people.openmoko.org/joerg/unsorted/gta04.pdf11:37
DocScrutinizer056.Optical mouse sensor as X/Y scroll­wheel11:38
DocScrutinizer05Additional 11:39
DocScrutinizer05use cases: ultra­precise detection of velocity, direction, and distance of movement of objects 11:39
DocScrutinizer05in relation to device, e.g. robotics, digitizing roads off paper maps, electronic folding meter 11:39
DocScrutinizer05rule...11:39
whitequarkright, pretty cool11:40
DocScrutinizer05[2014-02-23 12:42:31] <-- wpwrak has left this server (*.net *.split).11:47
DocScrutinizer05dman friggin DDoSers11:47
DocScrutinizer05I really wonder if that's the GCHQ or whatitscalled11:48
DocScrutinizer05or just a skiddie that found out how to write a NTP exploit11:48
DocScrutinizer05and now practicing11:48
whitequarkprolly skiddies11:49
DocScrutinizer05I also like to kick some IETF butts thru all the town11:50
DocScrutinizer05for doing an incredibly poor job when specifying some RFCs (see NTP etc)11:51
DocScrutinizer05connectionless echo with volume multiplier >1 should be punishable11:51
larscis this how the ddos is done?11:52
DocScrutinizer05in RFC speak: a machine MUST NOT answer to any inbound message that's not authenticated regarding its origin with an answer that's larger in size than the query11:53
DocScrutinizer05larsc: prolly11:53
larscDocScrutinizer05: as in you assume this, or people in general assume this?11:54
DocScrutinizer05NTP listsomething UDP, with fake source IP11:54
DocScrutinizer05people generally assume this, it's a known exploit seen in the wild during last few weeks aiui11:54
whitequarkthere's also routers which don't check source IP11:55
DocScrutinizer05send a UDP to vulnerable server: "protocol: NTP. command: tell me about your list of foobar! from: <IP of DDoS target>"11:56
DocScrutinizer05multiplier factor: up to several 10011:57
DocScrutinizer05depending on size of 2list of foobar"11:57
DocScrutinizer05[2014-02-22 23:57:11] <alamar> net4all: it's amplification using ntp (probably monlist) probably with requests sourced from networks not enforcing bcp-38 (and thus enabling the reflection) 12:00
DocScrutinizer05[2014-02-22 23:42:52] <xordern> The current attack seems to use NTP reflection.12:01
DocScrutinizer05[2014-02-22 23:44:13] <xordern> ... and this produces currently traffic up to 35000 Mbit per seconds.12:01
DocScrutinizer05[2014-02-22 23:58:25] <alamar> Rubas: your server can get ddos (and the traffic type does not matter) 12:04
DocScrutinizer05[2014-02-22 23:58:36] <alamar> if it's dns, ntp or snmp12:04
DocScrutinizer05[2014-02-22 23:59:02] <alamar> by "filling" the available bandwidht with "any kind of traffic" the legitimate traffic will eventually get lost12:04
DocScrutinizer05[2014-02-23 00:00:59] <alamar> with the current trend it's open ntp servers replying to monlist requests12:05
DocScrutinizer05[2014-02-23 00:04:08] <alamar> the original requests may be sourced from infected servers/pcs/whatever but are using spoofed IP addresses (using freenode server addresses) they contact lists of ntp servers asking for their monlist. ntp using udp which is a connectionless protocol not requiring any real interaction answers to the requests sending the data to the freenode servers (which did not ask for them). ntp monlists can be quite 12:06
DocScrutinizer05large (so if your request takes 10bytes and the answer is a 500byte long list you have an amplficiation factor of 50)12:06
DocScrutinizer05larsc: HTH12:07
DocScrutinizer05note that there seem to be other vulnerable protocols (snmp, dns, ...), thus my rant about IETF and their terribly poor protocol specs12:13
DocScrutinizer05hell, you could argue UDP never whould've been invented12:14
whitequarkI'd argue networks must obey bcp-38 rather12:15
whitequarkDNS works because it's stateless12:15
DocScrutinizer05TCP SYN/ACK is a minimalistic "authentication" layer at least12:15
whitequarkno fucking way you can answer billions of req/s with state tracking12:15
DocScrutinizer05right, SYN flooding is a problem in itself12:16
whitequarkyep12:16
DocScrutinizer05but a problem we know what's the possible cures12:16
DocScrutinizer05you never can defeat *all* kinds of DoS12:16
DocScrutinizer05but you can mitigate the impact12:17
DocScrutinizer05and make it expensive for the attacker12:17
DocScrutinizer05it's all a question of cost on either side12:17
DocScrutinizer05when the cost on attacker's side is magnitudes higher than the effort/cost to reject stuff at victim's side, a DoS attack becomes unattractive12:18
DocScrutinizer05hi dos112:19
dos1hello!12:19
dos1what's up?12:19
DocScrutinizer05NTP exploit ;-P12:19
DocScrutinizer05send a UDP to vulnerable server: "protocol: NTP. command: tell me about your monlist! from: <IP of DDoS target>"12:20
dos1oh yeah, DDoS multiplication12:21
DocScrutinizer05server sends monlist (which can be quite a bunch of data traffic) to <IP of DDoS target>12:21
DocScrutinizer05dos1: [2014-02-22 23:44:13] <xordern> ... and this produces currently traffic up to 35000 Mbit per seconds.12:22
DocScrutinizer05:-O12:22
DocScrutinizer05poor freenode12:23
dos1funny how such things become widely used after so much time12:23
dos1makes you wonder how many similar vectors exist in other commonly used software, just waiting for aha moment in someones mind :P12:24
dos1previously they used DNS, but monlist turned out to be much more effective12:25
DocScrutinizer05snmp12:26
DocScrutinizer05and there are a few others *known* to be vulnerable, aiui12:26
DocScrutinizer05they even exploited ICMP iirc12:27
whitequarkconsider you can scan 0.0.0.0/32 in a day or two *on commodity servers*12:27
DocScrutinizer05funny: ICMP package got sent to invalid IP, so the machine got a NAK and that created further ICMP to invalid IPs12:28
DocScrutinizer05maybe google for icmp-flood or sth like that12:28
DocScrutinizer05wpwrak: wb!12:30
DocScrutinizer05I wonder if eventually IETF will come up with a protocol RFC that allows banning of machines at POS level, in expression a inter-carrier protocol where destination end asks origin end to ban certain IPs resp their users physically from internet12:33
DocScrutinizer05? s/POS/POP/ ?12:33
DocScrutinizer05POP, Point Of Presence - iirc12:34
DocScrutinizer05an ancient obsolete term I guess12:34
whitequarkGEMA and MPAA would be so pleased12:35
DocScrutinizer05sure12:35
DocScrutinizer05but they already enforced/pushed this, though not on a protocol level12:35
whitequarkwhat you need is wider deployment of bcp-3812:35
DocScrutinizer05tbh nfc about bcp-3812:36
whitequarkand it would solve pretty much all UDP amplification attacks and some other12:36
whitequarkwell12:36
whitequarksource ip checking by routers12:36
DocScrutinizer05DPI12:36
DocScrutinizer05?12:36
whitequarkno, not really, I mean routers already compare destination ip with their tables12:36
whitequarkcould run one more lookup per udp packet12:36
DocScrutinizer05well, in which table shall a router at my ISP keep a record for that UDP packet I want to send to my SIP far end, to my NTP server stratum-4711, or whatever?12:37
DocScrutinizer05and where from originates that record in that table?12:38
whitequarkISP should reject all packets with source IP not originating from its network12:38
whitequarkit's a very basic rule12:38
DocScrutinizer05does UDP have source IP?12:39
whitequarkhow exactly could you answer to UDP otherwise?!12:39
DocScrutinizer05well, you can't12:39
whitequarklol what12:39
DocScrutinizer05aiui12:39
whitequarkall IP packets have src and dest IP12:39
whitequarkhttp://en.wikipedia.org/wiki/IPv4#Header12:39
DocScrutinizer05okok12:39
DocScrutinizer05more coffee needed12:40
whitequarkUDP is absurdly simple: http://en.wikipedia.org/wiki/User_Datagram_Protocol#Packet_structure12:40
DocScrutinizer05yeah, basically NAT and other crap is what kills the internet12:41
DocScrutinizer05;-P12:41
whitequarkwell, no NAT in IPv612:41
DocScrutinizer05generally all sorts of proxies that change source IP12:41
whitequarkexcept for dumb people who think they need to "hide their network structure"12:41
whitequarkwhich is frankly absurd but so awfully prevalent, or maybe they're just goddamn loud12:42
DocScrutinizer05:nod:12:42
DocScrutinizer05even wiki has it: http://en.wikipedia.org/wiki/Network_Time_Protocol#Security_concerns12:44
DocScrutinizer05>>Similar to a DNS amplification attack, an attacker sends a small command to the NTP server (typically the MON_GETLIST command) with a spoofed return address.<<12:44
dos1yep, it was actually "fixed" long ago in ntpd12:47
Action: DocScrutinizer05 glares at "[x] Fritzbox router serves as NTP server time normal for LAN"12:48
dos1but attackers now realized how many old, vulnerable versions are still out there12:48
dos1monlist got obsoleted and afaik it's not supported anymore at all in latest versions12:49
DocScrutinizer05fucking fritzboxen had a vuln in all builds and versions, opening up the admin web-UI to $world, without authentication needed12:49
DocScrutinizer05of course via admin UI you could flash arbitrary new frimware12:50
DocScrutinizer05:-o12:50
dos1yep, "NTP version 4.2.7, which removes the monlist command entirely"12:50
DocScrutinizer05I'd absolute not be surprised to find a 27.4 mio routers worldwide provide a vuln NTP implementation12:53
dos1who would? ;)12:53
DocScrutinizer05and particularly snmp implementation12:53
DocScrutinizer05you seen the story where some dude at a university had rooted all routers worldwide which had that backdoor vulnerability ?12:55
DocScrutinizer05by simply scanning THE INTERNET aka /3212:55
dos1the internet scan?12:55
DocScrutinizer05err /0 ?12:56
dos1http://internetcensus2012.bitbucket.org/paper.html12:56
DocScrutinizer05yup12:56
dos1I wonder how many of them are now mining some cryptocurrencies... :D12:57
DocScrutinizer05I wonder how many of them are now used in botnets for spam12:59
DocScrutinizer05and DDoS12:59
DocScrutinizer05https://www.quakenet.org/articles/102-press-release-irc-networks-under-systematic-attack-from-governments13:01
dos1the answer for that one is obvious: "lots of them" :P13:01
dos1even in that census it was mentioned that many of scanned targets already had some malware installed13:02
DocScrutinizer05when that's true, it's fucking ridiculous that (E)TLA agencies use illegal DDoS attacks to "fight" Anonymous and other groups that they think need to get extinguished because they do... DDoS attcks13:03
whitequarklet's just get rid of TLA jerks13:04
DocScrutinizer05hell, all the anti-western terrorists won the battle, really13:05
whitequarkI don't know, only the USA population seems to be actually moved by the "terrorist threat"13:05
whitequarkothers just use it as a convenient excuse13:05
DocScrutinizer05they managed to turn all our authorities into exactly the enemies of our western lifestyle13:05
whitequarkdid they do it? or did we do it to ourselves, ultimately?13:06
DocScrutinizer05western moral assets abolish themselves, during fighting threats put up to them by terrorists13:07
whitequarkweren't that strong then13:07
DocScrutinizer05http://masssurveillance.info/13:10
DocScrutinizer05http://leaksource.files.wordpress.com/2013/12/nsa-ant-picasso.jpg13:13
whitequarkpicasso seems to be tailored for covert agents, not surveillance13:13
DocScrutinizer05meh, not exactly13:17
whitequarkhmm?13:17
DocScrutinizer05it's just doing what can get done13:18
dos1speaking of surveillance - amazing (and kinda scaring) game: https://nothing-to-hide-demo.s3.amazonaws.com/index.html13:18
DocScrutinizer05and this type of malfirmware is available commercially for a few 1000 bucks to everybody nowadays13:18
DocScrutinizer05https://blog.torproject.org/blog/deterministic-builds-part-one-cyberwar-and-global-compromise13:19
DocScrutinizer05(`unrelated`)13:19
nicksydneywpwrak: ping13:43
whitequarkapparently this happens if you get NaOH in your eye: http://i.imgur.com/U7dyr4L.jpg13:47
Action: whitequark looks suspiciously on his bowl with 5% NaOH solution13:48
whitequarkin unrelated news I want a tshirt with this sign: http://3.bp.blogspot.com/-IrZOLGJB8rI/UrhOGlRO_3I/AAAAAAAAJO0/hOHbTc_cmeM/s1600/5220-1.jpg13:53
whitequarkthen it is very easy to respond to allegiations of being annoying: here, you've been warned13:54
larscIf only there was a way to order customized t-shirts13:58
whitequarklarsc: eh? I know it's simple14:01
larscyou said that as if it is still 199014:08
whitequarkaren't we talking via irc?14:17
larscthe communication technology of the future ;)14:22
whitequarkwow, I'm really impressed with this photoresist14:33
whitequarkit requires several *seconds* to develop14:33
whitequarknot even minutes. this time I developed it for 10 seconds and it was well damn ready at 514:33
whitequarkthis is so much better than the USSR-era crap I used in the past14:34
DocScrutinizer05whitequark: new photoresist?15:06
DocScrutinizer05ooh, I just notice you're logging the channel :-)15:07
DocScrutinizer05on unrelated sidenote: seems Nik and me sorted our organizational woes regarding Neo900 management15:08
DocScrutinizer05\o/15:08
whitequarkDocScrutinizer05: (photoresist) yeah, imported one: http://www.amazon.com/gp/product/B00B0Z8AZ6. very good.15:10
whitequarkI was using it for a long time though, but I just noticed how fast it actually develops15:10
whitequarkit kinda evaded my sight before, I just kept brushing it around, thinking "it could not develop that fast"15:11
whitequarkand actually damaging the exposed layer15:11
DocScrutinizer05so you used that PhRes for your recent studies, or a crappy old one?15:11
whitequarknew photoresist for all recent stuff15:12
whitequarkcrappy old one was like five years ago15:12
DocScrutinizer05aah15:12
whitequarkby the way I'm logging this channel from, I think, late 201115:12
whitequarkor late 201215:13
DocScrutinizer05I just got aware of that15:13
DocScrutinizer05never looked closely to the URL before15:13
whitequarkright, late 2011. so 2.5 years already15:13
whitequark(org woes) \o.15:14
whitequark*\o/15:14
DocScrutinizer05yeah, will still create a certain amount of annoying mess, but should pan out fine in the end15:14
whitequarkwpwrak: what do you do if you get copper 'bridges' between closely adjacent traces?15:16
DocScrutinizer05unless I get hit by a bus, in which case the project was severely on peril (but hey, maybe it would be anyway in that case?)15:16
whitequarkoh let me guess, you don't with your devil mixture15:17
DocScrutinizer05hehe15:17
DocScrutinizer05usually you use a sharp knife15:17
DocScrutinizer05though I sometimes prefer a 10A lab PSU ;-)15:18
dos1DocScrutinizer05: stay away from buses!15:18
DocScrutinizer05dos1: sure! :-D15:18
whitequarkdos1: I don't think he could work on electronics then15:19
DocScrutinizer05hehehehe15:19
dos1:D15:20
DocScrutinizer05"PCI bus ran over me! :-S"15:20
DocScrutinizer05wait, PCI isn't a bus actually15:21
DocScrutinizer05make that I2C then15:21
DocScrutinizer05for simplicity ;-)15:21
whitequarkPCI isn't a bus?15:21
DocScrutinizer05ooh, obviously still lack of coffee15:21
DocScrutinizer05PCIx or whatsitcalled15:21
whitequarkPCIe is p2p, right15:21
DocScrutinizer05:nod:15:22
whitequarkprobably can't be called a bus. you don't have an 'UART bus'15:22
Action: whitequark carefully peels photoresist traces off board15:22
DocScrutinizer05you also don't really have a ethernet nnnBt bus15:22
whitequarkit's oddly satisfying, like peeling sunburnt skin15:22
DocScrutinizer05lol15:23
DocScrutinizer05I can't recall when I last time did that15:23
DocScrutinizer05sun? what's that?15:23
whitequarklol15:24
DocScrutinizer05peeling off dead skin from burn injuries, very common15:24
DocScrutinizer05but those burns are usually from hot objects, rarely from flames15:25
DocScrutinizer05never from sun15:25
whitequarkI think I grew bored of handling soldering iron with bare fingers a few years ago15:25
whitequarkwell... sunburn is caused by UV15:25
DocScrutinizer05yeah, sure15:25
whitequarkso if you decide to reproduce my PCB fab and use a 1000W gas discharge lamp for exposure, you can get one15:25
DocScrutinizer05and I guess my last "sun"burn been actually a welding burn15:26
whitequarkha, I guess that works too!15:26
DocScrutinizer05I'm pondering to get a UV-B lamp of some sorts, to get some ozone and UV bleaching into my cave15:27
whitequarkso this board: http://i.imgur.com/3XRXKgg.jpg15:27
whitequarkit's kind of shitty actually. I'm wholly dissatisfied by it.15:28
whitequarkoh by the way: I drilled the holes before etching15:28
DocScrutinizer05just wondering what type of lamp precisely I should get. Maybe get a simple HQI and break the UV protector glas?15:28
whitequark(HQI) mercury, isn't it forbidden in germany? RoHS and all that15:29
DocScrutinizer05not in lamps15:29
DocScrutinizer05actually every crappy energy-saver lamp comes with Hg15:29
whitequarkwell, not led ones15:30
DocScrutinizer05FL lamps 15:30
whitequarkalso those contain about 2-3mg of Hg in them15:30
whitequarkand a single HQI lamp contains a whole drop of 1-2g probably15:30
DocScrutinizer05nah!15:30
DocScrutinizer050.1g maybe15:30
whitequarkthough, considering how much of them there are sold... HQIs are probably less bad for environment at the end15:30
whitequarkoh fuck this, I'm going to get some H‚O‚. let's see if persulphate+H2O2 even works15:31
DocScrutinizer05(PCB) yeah. looks nice from distance, terrible in close-up15:31
whitequarkperhaps I got too excited and underdeveloped it15:32
whitequarksome invisible traces of resist15:32
DocScrutinizer05(persu + perox) you're the chemist15:32
whitequarkin this case I'm http://media-cache-ec0.pinimg.com/736x/01/93/c4/0193c494a78dd90bf914f37f62eceda2.jpg15:32
whitequarkhonestly it would be very hard to say from a purely theoretical standpoint how H2O2 would affect the reaction15:33
DocScrutinizer05you should do a proper development test series, find when it starts "developing" aka the stuff that shall go does go, and when it starts "over developing" means when the stuff that shouldn't starts to go15:33
whitequarkthat shit's really complex to model. in uni they just show you whatever cases are conveniently explained15:33
whitequarkhmmm15:34
whitequarkwell, it starts developing immediately. as I've said it's nearly complete in 5 seconds15:34
DocScrutinizer05guessing from both are oxidizers and based on oxygen, I doubt anything will happen 15:35
whitequarkuhhh15:35
DocScrutinizer05(immediately) then you got $l for your formula ($l + $h)/2 seconds15:36
whitequarkDocScrutinizer05: $h is really hard to figure out, because it doesn't just start to eat exposed areas15:37
whitequarkno, rather it digs under them and then they detach sometime during etching.15:37
DocScrutinizer05when $l is 5s and $h is maybe 90s, then you should develop stuff for ~40s15:37
whitequarkI'll try to look for tiny bits of unexposed unremoved resist. I can't see them with eye but maybe my macro lens would help15:37
DocScrutinizer05yeah, that's why I said you should do a test series15:37
whitequarkhm, MSDS for persulphate:15:38
whitequarkNOTE: Decomposes slowly in water to produce15:38
whitequarkoxygen ozone 15:38
DocScrutinizer05pretty simple to dunk a exposed PCB into NaOH solution, 1cm per 10s15:39
whitequarkDocScrutinizer05: it's not developed with NaOH, rather K2CO315:39
DocScrutinizer05ooh, whatever15:39
whitequarkNaOH immediately removes all exposed and unexposed resist15:39
DocScrutinizer05what's K2CO3? backing soda?15:39
DocScrutinizer05not exactly15:40
whitequarkno, that's KHCO315:40
whitequarkor NaHCO315:40
DocScrutinizer05Na, I guess15:40
DocScrutinizer05so, has that stuff a name?15:41
whitequarkwhich stuff? K2CO3? potash I think15:41
DocScrutinizer05ooh15:41
whitequarkbtw I'm looking up mechanism of reaction of S2O8 anion15:42
whitequarkit's very interesting. in some environments it actually *produces* H2O215:42
DocScrutinizer05yep15:42
DocScrutinizer05and I seem to recall it gets produced using H2O2?15:42
whitequarkno clue about production15:43
whitequarknow, I wonder how can I cause it to produce H2O215:43
whitequarksince the latter is apparently "kinetically faster" which is not surprising at all15:43
whitequarkohhh, pH 0.3 to 315:44
DocScrutinizer05umm, catalyst?15:44
whitequarkgotta make that crap slightly acidic15:44
whitequarkgrmbl. wonder if I can buy battery acid here.15:44
DocScrutinizer05a few drops of an acid will prolly help, yes15:44
whitequarkwell not "a few drops", a carefully measured amount :p15:45
DocScrutinizer05"funny" sidenote: ammonia persulfate is rated here in Germany. Not exactly simple to purchase 15:45
whitequarkoh? why?15:46
DocScrutinizer05dangerous?15:46
DocScrutinizer05dual use?15:46
whitequark"dangerous" is bullshit, you can kill yourself easily with just about anything15:46
whitequarkdual use... none I'm aware of15:46
whitequarkoh also, persulphate is not even particularly toxic. your toilet cleaner is much much more dangerous15:47
DocScrutinizer05maybe even because of H2O2?15:47
DocScrutinizer05well, persulfate seems a semi-decent oxidizer for blackpowder-alike explosives15:48
whitequarkdo you ever not think of explosives? :D15:48
DocScrutinizer05actually... no15:48
whitequarkwasn't even a doubt on that15:48
DocScrutinizer05a bad habit from my youth I never could get rid of. Started at the age of ~715:49
DocScrutinizer05when I hear ".*per.*ate" I get excited ;-)15:50
whitequarkhaha15:50
DocScrutinizer05actually potasium chlorate doesn't even have a "per" in it15:51
DocScrutinizer05still wondering where to get tetranitromethane15:53
whitequarkusually perchlorate is used for these purposes15:54
whitequarkour chemistry teacher in highschool mixed that with red phosphorus. he was *really* excited while doing this.15:55
whitequarkI think I couldn't hear anything for about five minutes afterwards15:55
whitequarkanother nice episode happened when he cooked Al2C3. he put prolly less than a gram of reagents into a crucible and started to heat it. I was filming the whole thing on my phone15:56
whitequarkthen at some time it, um, reacted. the crucible cover immediately flew up 2.5m and left an imprint on the ceiling15:57
whitequarkI dropped the phone. the record was kinda cool: first it cooks on a torch, then it's all bright white, then a loud bang and it ends with a black screen :p15:58
DocScrutinizer05hehehe, where's the youtube link? and... Al2C3?16:00
DocScrutinizer05aluminiumcarbide?16:00
qi-bot[commit] Paul Cercueil: Fix launching non-OPK apps with files with special characters (master) http://qi-hw.com/p/gmenu2x/c19e78916:00
qi-bot[commit] Paul Cercueil: Added key repeat on analog sticks and hats (master) http://qi-hw.com/p/gmenu2x/7777b9e16:00
whitequarkDocScrutinizer05: no youtube link sadly16:02
whitequarkI think youtube killed my old account because there was another clip with music from crazy frog overlaid16:02
whitequarkand some copyrast decided it had to die16:02
Action: DocScrutinizer05 tries to recall that weird (at least back when I thought it's weird) story about an explosive created from heating a metal with err backing soda or sth similar16:02
whitequarkaluminium carbide, yes16:02
whitequarkbaking soda? metal? exploside? weird16:03
DocScrutinizer05I can't recall the details. How would you create Al-carbide?16:03
whitequarkhttp://chemistry.about.com/b/2013/06/10/black-snakes-from-baking-soda.htm ?16:03
whitequark(Al2C3) by reacting Al and C, duh16:04
DocScrutinizer05nah, wait, I think it involved sulphur16:04
DocScrutinizer05ooh, you mix Al and carbon and that explodes?16:04
whitequarkafter heating to IIRC 600°C or something16:05
DocScrutinizer05mhm16:05
whitequarklol wikipedia16:06
whitequark"Melting point2200 °C[2]16:06
whitequarkBoiling pointdecomposes at 1400 °C[3]"16:06
DocScrutinizer05errr16:07
whitequarkwtf, why does google consider "carbide" and "nitride" equivalent and substitutes them in my queries?!16:08
whitequarkanyway I'm off to buy some peroxide16:10
whitequarkif that works, I can later add acid to solution, with hopefully same effect16:11
whitequarkbut permanent16:11
Action: DocScrutinizer05 wonders what opening hours have the shops in moscow16:28
DocScrutinizer05whitequark: btw in http://i.imgur.com/3XRXKgg.jpg the footprints don't match the hole diameter16:31
DocScrutinizer05s/footprint/pad/16:31
DocScrutinizer05whitequark: and what's that circuit the PCB is for? a controller with 3 LEDs and a 2wire bus to $world?16:35
DocScrutinizer054-wire?16:35
DocScrutinizer05hmm, it seems to have no power supply on the connector16:36
DocScrutinizer05only battery pads16:36
DocScrutinizer05connector looks like GND, output, gpio, gpio, gpio16:37
DocScrutinizer05prolly the connector is just for in-circuit-programming?16:39
DocScrutinizer05\o/ http://trendwatching.com/briefing/16:41
wpwrakbuying peroxide on a sunday, at night. hmm. either it's weak peroxide and the shop is a pharmacy, or it's strong stuff and the shop is 24/7 supplies for the ... hmm ... pharmaceutical entertainment industry :)16:42
DocScrutinizer05run by an individual that must avoid running into any police control16:43
DocScrutinizer05;-P16:43
whitequarkDocScrutinizer05: (opening hours) it depends. in center it/s 24/7 for a lot of shops, and 9-11 for others16:58
whitequark(hole diameter) why you think so?16:58
whitequark(PCB is for) just a test PCB with atmega8 and 3 leds16:59
whitequark(connector) yes, just ICSP indeed16:59
whitequarktest pads are for power source16:59
whitequark(peroxide) pharmacy obviously16:59
whitequarkI can order strong stuff completely legally, but it'll take a few days to ship it from St. Petersburg17:00
whitequark(legally) I give them my complete ID17:00
whitequarkand I have to show same ID when receiving parcel17:00
DocScrutinizer05LOL, I just found out my LG TV doesn't want to switch to videotext after audio got muted. It however allows muting audio after switched to videotext17:04
DocScrutinizer05I own this TV for maybe 5 years now17:05
DocScrutinizer05never noticed that bug17:05
DocScrutinizer05(diameter) the pads are too small for the holes17:05
DocScrutinizer05not enough copper around the hole, at sides17:06
whitequarkhrm17:12
whitequarkit should be 1.0 mm17:12
DocScrutinizer05that trendwatching mentioning is actually pretty nice17:16
DocScrutinizer05(though in direct neighborship to bloks nonsense :-S ) 17:17
whitequarkheh17:19
whitequarkDocScrutinizer05: hmm you seem to be right (maybe). my possibly inaccurate measurement indicates 1.115mm holes17:23
whitequarkperhaps spindle runout? .1mm seems in the right ballpark for that crappy chinese spindle17:23
DocScrutinizer05what happened to the Phres covering the holes?17:26
whitequarkit stayed on half of holes and broke away on others17:27
whitequarkhowever it never covered it from *other* side of this onesided PCB17:27
whitequarkso etchant could freely access copper though hole itself17:27
whitequark>No more products, development cycles or campaigns built around planned obsolescence. Instead, smart brands will plan, build and sell for constant iteration.17:37
whitequarkcute. rather what happens is digitally locking you out of features to force you into a subscription model.17:38
whitequark>A world of new information for consumers to track, share and then act on (such as the driving data made possible by Automatic, above).17:38
whitequarkconsumers, yeah.17:38
whitequarkwow, MSDS on persulphate:17:45
whitequark Persulfates decom-17:45
whitequark pose to form solid sulfate salts and emit noxious fog or17:45
whitequarkfumes of SO x and NOx . This decomposition may form a17:45
whitequark high temperature melt. The material will flow like magma17:45
whitequarkmagma!17:45
Action: wpwrak wonder how long until whitequark comes around and accepts that HCl is the only resonable choice :)17:47
whitequarkmeeeh17:48
DocScrutinizer05vomit on your PCB X-P17:51
Action: DocScrutinizer05 idly ponders electro-erosion17:52
DocScrutinizer05high frequency AC current, and a tungsten spike for the arc17:53
DocScrutinizer05AC for the "grounding" of the PCB: by a large area electrode hoovering 1mm above the PCB, that has a maybe 3..5mm hole in the midle, for the arc17:54
wpwrak(self-made etchant) maybe eat something really hard to digest first so the stomach increases the acidity17:57
whitequarkit doesn't quite work like that18:07
DocScrutinizer05or simply read poettering's blog or something like that ;-)18:08
whitequarkanyway, stomach pH is always around 1-2 so it'll fit if not for contaminants18:08
whitequark(poettering) hehehe18:08
DocScrutinizer05after reading that, I probably can cut the traces by glaring at the PCB18:10
whitequarkI'm afraid it'll delaminate and/or turn into toxic vapor18:10
whitequarkanyway, whitequark vs pcb round 218:12
DocScrutinizer05:-)18:12
DocScrutinizer05s/round 2/sour/18:12
whitequarksour?18:12
DocScrutinizer05not?18:12
whitequarkoh, "sour" as "acidic"18:13
whitequarkwell no, I bought H2O2 but no acid18:13
whitequark*cough* one of the cases where lack of acid severely impedes progress *cough*18:13
DocScrutinizer05hm?18:14
whitequarkthe other one is apparently smartphones18:14
whitequark(steve jobs really liked lsd)18:14
DocScrutinizer05ooh18:14
DocScrutinizer05didn't know that18:14
whitequarkquote, "one of the best things I did in my life"18:14
whitequarks,things,decisions,18:14
DocScrutinizer05to take acid?18:15
whitequarkyes18:15
DocScrutinizer05hehe18:15
DocScrutinizer05well, depending on when he did, I might concur18:15
whitequark'when' ?18:16
DocScrutinizer05I think all that prychedelic stuff is fine while you are about to develop a mind, once you go productive it's more hindering than giving any benefit18:16
DocScrutinizer05IOW it's a lerning tool maybe, but for sure no production resource18:17
wpwrakyou mean you'd only give it to kinds ? :)18:17
whitequarkyeah, sounded weird for me too18:17
DocScrutinizer05wpwrak: not exactly to kids, but yes, basically18:18
whitequarkessentially since it appears that on kids even innocent stuff like lsd and pot can (even if not often) cause lasting negative consequences18:18
DocScrutinizer05maybe the age between 16 and say 30 max is the right time for such experiments18:18
whitequarkinteresting opinion18:19
DocScrutinizer05I'd even say, 25 to 3018:20
wpwrak20-70 ? :)18:20
DocScrutinizer05but then, how should I know, I dunno both alternatives18:20
whitequarkwell, current consensus is that frontal lobe development finishes at about 2518:21
dos1good, so I still have few years to develop it properly... :)18:23
wpwrakwell, now you have a project: find a bunch of nice girls, father a child with each, then administer LSD to them at different ages. study the results. publish either under the pseudonym Frankenmann oder Hoftstein18:23
whitequarkmore like Dr. Mengele18:23
wpwrakis he already a classic ?18:24
whitequarkplus the sample size is too small18:24
whitequarkwell... he isn't?18:24
whitequark(reminds me of https://xkcd.com/507/)18:24
DocScrutinizer05the whole drug legislation isn't driven by scientific reasoning, that's for sure18:27
DocScrutinizer05wpwrak: I thought you ask "is he already dead? I seen him last week"18:28
DocScrutinizer05he might be your neighbour for all I can tell18:28
whitequarkha18:29
whitequark(drug legislation) well, not everywhere in the world... europe seems to be saner about this18:30
DocScrutinizer05not really18:30
whitequarkin US it's a deeply religious topic for sure, both metaphorically and literally18:30
dos1depends on which part of europe18:30
dos1and it varies in time as well18:30
DocScrutinizer05Europe in the err 30s of last century only agreed to place pot on the index when they were allowed to continue exporting some chemical that's needed for herion production18:31
DocScrutinizer05sth along that line18:32
DocScrutinizer05and s/Europe/Germany/18:32
DocScrutinizer05meanwhile they bred a whole new scene of designer drugs that are not known by law and thus not forbidden, just because they had that insane politics regarding the "classical" drugs18:35
DocScrutinizer05of course that new crap is extremely dangerous and not under any control or research18:36
whitequarkwell, designer drugs were inevitable18:36
DocScrutinizer05not really18:36
whitequarkand afaik at least in some countries laws are formulated in a way which extends to functionally equivalent drugs18:36
whitequarkI dunno about germany specifically18:37
DocScrutinizer05nobody would've bothered creating them when the known drugs would've been less outlawed18:37
DocScrutinizer05hah! "functionally equivalent" - where does that stop? at coca cola? coffee, alcolhol, jogging?18:37
wpwrakfood !18:38
DocScrutinizer05so you say weed is legal when I prepare a salad from it?18:39
DocScrutinizer05:-P18:39
wpwraknaw, i say food should be outlawed, too. after all, a nice meal makes you feel good. we can't have that, can we ?18:40
DocScrutinizer05and: who are the testers to check the physiological effects of an unknown substance to decide if it's legal or not? bwahahaha!18:41
wpwraki suspect that a good portion of the obsity in the US can be traces to prohibition / stigmatization of all the other sources of "feel good" stuff18:41
DocScrutinizer05yep18:42
whitequarkor to the fact that you have access to cheap nutritious food18:42
whitequarkI mean, the most obese country now is Mexico18:42
wpwrakcultural contamination18:43
DocScrutinizer05I guess two of the top 10 facotrs are: nutrisweet (and other sweeteners), and that hormone stuff in plastic18:44
whitequarkthat's really unfounded claim :)18:44
DocScrutinizer05no18:44
whitequarkwell... such things can be confirmed by large-scale studies or metaanalyses18:45
whitequark10k+ people18:45
whitequarkdo you have one?18:45
DocScrutinizer05for both there is scientific evidence that they result in users getting fat18:45
whitequarkotherwise it's mostly picking the data points you like for an arbitrary p-value, unfortunately even in quite some scientific studies18:45
DocScrutinizer05of course for both there are like 30 times as many studies that say those substances are perfectly safe and the best thing indistry ever invented18:46
whitequarkit's not as much quantity of studies as quality18:47
DocScrutinizer05check out the history of nutrasweet, it will make you puke or pick your kalashnikov18:47
whitequarkand of course you have to watch affiliations of researchers18:47
whitequarkbut still. lack of good evidence is a well-known problem in medicine today18:47
DocScrutinizer05in some countries nestle(?) did a study three times, until the result was as they expected, to get the crap thru the food&drug-admin certification18:48
whitequarkyep, unpublished studies. another known problem18:49
whitequarkI think there's an initiative in UK to force pharma to disclose all such results18:49
DocScrutinizer05ooh, those even were published18:49
whitequarkoh? then it's some lousy job on FDA side18:49
DocScrutinizer05but then they just waited for a new leader of the local FDA and repeated the opproval process with a new study18:50
DocScrutinizer05or even the same study18:50
DocScrutinizer05it's incredible what is going on there18:50
whitequarkregardless, by picking just the results you like you're no better than pharma18:51
whitequarkexcept to the other extreme18:51
wpwrakjust wait until those who got sick have died, then add that given zero incidence of sickness, mortality has not been studied18:51
DocScrutinizer05yep18:53
DocScrutinizer05whitequark: I'm picking the results industry didn't like but found no better way than bribery to defeat them18:55
whitequarkso you admit you're biased18:55
DocScrutinizer05if those results were based on false studies, it would've been a joy for indistry to defeat those studies on a scientific level18:56
whitequark18:46 < DocScrutinizer05> of course for both there are like 30 times as many studies that say those substances are perfectly safe and the best  thing indistry ever invented18:56
whitequarkit appears they did, but you ignore it because of a prejudice18:56
whitequarkor is that not so?18:56
DocScrutinizer05no, since those 30 studies been paid by industry, and most of them obviously faked18:58
DocScrutinizer05[2014-02-23 19:55:10] <DocScrutinizer05> whitequark: I'm picking the results industry didn't like but found no better way than bribery to defeat them18:58
whitequarkhow exactly industry can defeat studies on scientific level without sponsoring another one? you're contradicting yourself18:59
DocScrutinizer05mhm, sure18:59
DocScrutinizer05maybe discuss that with the author of that report in TV? instead of me19:00
whitequarka good way would be to hire an independent researcher. but then you can just claim they were bribed19:00
whitequarkit's a catch-2219:00
DocScrutinizer05yeah, that's what industry wants to make you believe19:01
whitequarkI don't give a fuck about industry. I give a fuck about better drugs19:01
whitequarkand having a good drug recalled because some random guy cries "bribery" loud enough is just as bad as the opposite19:02
whitequarkneither of those have any relation to science19:02
DocScrutinizer05I'm not interested in that topic. I said nutrasweet makes you go fat like a whale19:03
DocScrutinizer05and that been tested by universities with animals19:03
DocScrutinizer05and the bisphenol case is even accepted by industry itself19:03
DocScrutinizer05partially19:04
DocScrutinizer05of course they still argue that the stuff doesn't escape from soda bottles into the soda19:04
DocScrutinizer05but whole EU forbid that crap at least in baby bottles and other stuff that toddlers might suck on or eat from19:05
wpwrakwe don't want no pictures of fat babies. fat kids, that's okay.19:06
whitequarkexcept no state-level health agency ever found it toxic even to babies19:06
whitequarkWHO, FDA, EFSA, Health Canada, etc, etc19:06
DocScrutinizer05that's exactly the nonsense rationale. Hormones are not toxic19:07
whitequarkthis claim is just moronic19:07
whitequarkand it suggests you didn't even read the reports, because those don't play with words like you suggest19:08
whitequarke.g. quote: "In vivo studies have not consistently demonstrated either androgenic or anti-androgenic activity of BPA."19:10
DocScrutinizer05aha, moronic. I just answered your statement. So when my answer been moronic, what been your statement then?19:14
whitequarkno one ever claimed that BPA is safe because it acts like a hormone but hormones are not toxic19:15
whitequarkI don't know where could you source that answer19:15
DocScrutinizer05and I wonder why bisphenol-A and a number of other softeners is forbidden for baby ,ilk bottles then19:15
whitequarkbecause one of 'environmental' organizations good mainly at self-promotion and raising money induced a public outcry. that's all.19:16
DocScrutinizer05mhm19:16
whitequarksame reason as e.g. with illegal drugs you mentioned above. public policy in this case is far, far from rational19:17
whitequarkguess what, if 100k people phone their MP and tell "ban BPA", BPA will be banned19:18
whitequarkbut that doesn't make them right19:18
DocScrutinizer05guess what, for that gene manipulated corn it didn't work that way19:21
DocScrutinizer05literally nobody here in Germany wants it, yet Germany didn't vote against it in EU 19:22
DocScrutinizer05not even the reports from MExico about that crap corn causing *more* instead of less pesticides getting used did change that19:23
whitequarkhttp://articles.mercola.com/sites/articles/archive/2009/05/05/germany-bans-genetically-modified-corn.aspx ?19:24
DocScrutinizer05nah, search for recent stuff19:25
DocScrutinizer05like, this week19:25
whitequarkI'd also want to see some pools about GM corn in Germany19:25
whitequarkcan't find sources for it, but in e.g. czech about half of residents are okay with it19:25
DocScrutinizer05http://www.google.de/search?q=genmais+150719:28
whitequarkokay, I can't find any polls except Greenpeace-sponsored ones19:33
whitequarkthere's this: https://www.openpetition.de/petition/online/stoppt-gen-mais-1507 but seems like no one either knows or cares19:34
whitequark1k5 people19:34
larscI never quite understood why the general public is so against gm stuff19:35
whitequarklarsc: so far I don't even see general public being so against. rather a very vocal minority promoting itself via fads.19:35
whitequarkall articles I see by that query are either describing facts (there's a split in germany, etc) or is "greenpeace greenpeace"19:36
whitequarkand polls in other parts of europe are 50/50 at worst, definitely not so polarized as they claim19:38
DocScrutinizer05well, I don't need any polls in media. I can do my own polls in my neighborhood19:39
whitequarkit surely isn't representative of EU, Germany, even the city you're in19:40
DocScrutinizer05larsc: maybe because it's totally useless, and they don't care about the genes "escaping" and irreversibly polluting "nature"19:40
DocScrutinizer05whitequark: I'm not going to argue on that level with you. larsc also said "...why the general public *is* so against gm stuff"19:41
DocScrutinizer05it's even stated in the agenda of our new fresh government, that we don't want GMO in Germany19:42
whitequarkyeah, I already see you'd happily pick data points to support your arbitrary claim19:42
DocScrutinizer05nevertheless they voted contrary in recent EU decision19:42
whitequarkthose news said "abstained"19:43
DocScrutinizer05whitequark: and you do what? argue for the fun of it?19:43
whitequarkpassing time while board cleans19:44
DocScrutinizer05whitequark: I don't enjoy this silly argument with you. abstained means "voted against a ban" when the vote is set up so itz needs a certan number to vote FOR the ban or otherwise it will not happen19:44
larscit means we are against it, but we don't want to say we are against it ;)19:46
DocScrutinizer05and I won't continue arguing about any such stuff with you, since I'm seeing *you* for sure are biased19:46
whitequarkI simply want to see science and not a witchhunt at work19:47
whitequarkguess that's futile.19:47
DocScrutinizer05for sure the government added that phrase about GMO to their agenda just because they were picking arbitrary data points to support ... what exactly? 19:47
DocScrutinizer05that's for sure futile19:48
whitequarkgrrr. fucked up attaching resist.19:49
wpwrakDocScrutinizer05: btw, any news (hopefully good) from the neo900 peace talks ?19:51
DocScrutinizer05[2014-02-23 16:08:31] <DocScrutinizer05> on unrelated sidenote: seems Nik and me sorted our organizational woes regarding Neo900 management19:56
wpwrakoh, great ! congratulations !19:56
DocScrutinizer05prolly I'm gonna leading the project19:57
DocScrutinizer05not really happy with that, but somebody needs to lead it19:58
wpwrakas long as you can get him to keep the bookkeeping and such :)19:58
DocScrutinizer05nope, that's my job19:58
wpwrakah, that sucks19:58
DocScrutinizer05yep19:58
DocScrutinizer05but that's life19:59
wpwrakyeah, someone's gotta do it ...19:59
DocScrutinizer05there has to be one person with the hat on, and that person also is holding the credit card20:00
wpwrakand can see that you'll want to be that person ;-)20:00
DocScrutinizer05I can't ask my butler to do the boring dealing with money for me20:01
DocScrutinizer05no, actually I would prefer when somebody else would lead the project and do all that stuff, but Nik prefers me doing it20:02
wpwrakwell, in many companies it works like that. finance has usually no authority to deny payments (unless somethings is badly wrong)20:02
DocScrutinizer05sure, but that would require neo900 group hiring Nik as our finance officer20:03
DocScrutinizer05and the bookkeeping is only one aspect20:03
DocScrutinizer05also the account is not on the person who does the finance, when you got that situation in a company20:05
DocScrutinizer05which boils down to: when neo900 group (or me) is leading the project, the funds can't sit on GDC account20:06
wpwrakusually not, but that may not be as much a requirement than simply being something that wouldn't make sense otherwise20:06
dos1hah, just wanted to ask about the funds :)20:06
DocScrutinizer05it's all just about the funds20:07
dos1so, what happens to them after all?20:07
DocScrutinizer05we probably are going to send out a mail to all donors, asking them to confirm/allow transfer of their donation from GDC to Neo900 group20:07
wpwrakso you'll create a company or an eV and then transfer the funds there ?20:07
DocScrutinizer05yep20:07
dos1sounds reasonable20:08
DocScrutinizer05those donors who don't allow that will not contribute to Neo900 development20:09
DocScrutinizer05GDC can't use their donation for anything, and Neo900 group can't access it20:09
wpwraksuckish. you'll lose a few in the process, simply because they don't see your mail, etc.20:10
DocScrutinizer05yeah20:10
DocScrutinizer05we obviously screwed that up from beginning20:11
dos1I think only pledges under 100 EUR are at risk of being lost that way20:12
dos1some smart part of them, that is20:12
DocScrutinizer05I need to sort out with Nik about how users/donors send back answers - sending a fax isn't probably going to pan out in the end20:13
dos1s/smart/small/ lol20:13
DocScrutinizer05o.O qi bot is weeeiiiiird20:13
dos1DocScrutinizer05: won't e-mail be enough?20:15
DocScrutinizer05that's a point to evaluate with Nik20:17
DocScrutinizer05I dunno what his lawyer/clerk/tax-advicer thinks is needed20:17
apeletewpwrak DocScrutinizer05: wrote a small piece to keep track of my soldering tools and record the advice you gave me:20:18
apeletehttp://apelete.seketeli.net/smt-soldering-tools.html20:18
apeletewpwrak DocScrutinizer05: here is a shot of the ridiculously heavy power supply brackets that came with the soldering station:20:20
apeletehttp://apelete.seketeli.net/content/pictures/soldering-station-power-supply-brackets.jpg20:20
apeletewpwrak DocScrutinizer05: any idea what those are intended for ?20:21
DocScrutinizer05:-o nope20:21
wpwrakwall-mounting ? maybe they were supposed to put one into the box and someone typed "100" :)20:24
wpwrakarticle is nice20:24
apeletethat's 3Kg of useless steel then :-)20:25
wpwrakpretty much, yes20:25
apeletewpwrak: I used the soldering station today, to solder a few wires on the gcw-zero:20:29
apeletehttp://apelete.seketeli.net/content/pictures/gcwzero-serial-wires-overview.jpg20:29
apeletewpwrak: it's a fantastic tool :)20:29
DocScrutinizer05sell the brackets on bay20:31
apeleteDocScrutinizer05: heavy like they are, shipping will be more expensive than the steel itself :)20:32
apeleteplus I don't even know what to say to the buyer, since I don't what those are20:33
wpwrakyou just copy the label and add the picture ;-)20:38
wpwraksoldering looks almost good. you should expose less wire and also try to keep the strands from fanning out20:39
DocScrutinizer05I bet some bored packer had a article number on his/her paper, seen same article number on the bag with clamps, and picked the bag to ship it20:40
DocScrutinizer05so at least one ot two of the clamps should *somehow* fit to the tool20:40
wpwrakyou can do the latter by holding the strands between two fingers and rotating the wire. then tin (solder) the exposed end of the wire and cut off anything you don't need20:41
apeletewpwrak: had a hard time soldering the black wire to the gnd pad, so I finally put it in the upper corner of the pcb20:41
apeletebut the strand fanning out is a mistake, my hand was shakky :-(20:42
DocScrutinizer05looks abit like you're adding too much solder, and not adding it to object to solder but to soldering iron tip20:42
wpwrakDocScrutinizer05: with SMT, you usually don't have much of a choice ...20:43
wpwraknot enough hands ;-)20:44
wpwraka prehensile tail (with fingers) would be useful for that. alas, evolution didn't think of that in time20:45
wpwrakapelete: e.g., the green wire looks as if it almost touches the capacitor. a little push and it's short RX. and you'll spend a bit of time searching the problem :)20:46
apeletewpwrak: wow, didn't even see that one. was worried about how close rx and tx wires were20:49
apeletedidn't test the serial output yet, I haven't receive the serial-to-usb converter bought off ebay20:50
apeletewpwrak: could a magnifying glass help for smt soldering ? was thinking about getting one of these:20:55
apeletehttp://www.ebay.fr/itm/Helping-Third-Hands-Soldering-Stand-Magnifier-Glass-Clamps-Modelling-Stand-/181177253410?pt=UK_Home_Garden_PowerTools_SM&hash=item2a2f017e2220:55
DocScrutinizer05apelete: anyway thanks for the nice attribution :-)21:00
DocScrutinizer05for that type of wiring you want max 1mm blank wire21:01
DocScrutinizer05abs max 2mm21:02
DocScrutinizer05will suffice completely to make fine contact to the pad21:02
apeleteDocScrutinizer05: you're welcome, had a good laugh while learning a lot that night21:03
DocScrutinizer05then you wet that 1mm with solder. you add a tiny solder bead to the pad. Then after adding a bit of flux to both, you put the wire end on top of bead and heat both with your soldering iron chisel tip. Reflow and contact will come after some 2..3s the latest21:05
DocScrutinizer05ooh, and don't forget to twist the wire strands as suggested by wpwrak, before you're wetting the wire with solder21:06
DocScrutinizer05I love to use the 1..2mm cut-off end of plastic and turn that while pulling it off the wire21:07
DocScrutinizer05but that depends on you cutting carefully through the plastic before you pull it off. Not exactly simply without cutting some of the strand wires as well21:08
apeleteyes, judging from the pictures I definitely need some practice21:10
apeletebut it went way better than the first time, working on the ben nanonote21:10
apeleteI guess the better tools helped a lot :-)21:10
DocScrutinizer05sure21:15
DocScrutinizer05what did that other guy say? "with the right tools everybody can solder. With bad tools even experts hardly can solder"21:15
DocScrutinizer05"it's eeeeeeasy!" ;-)21:16
DocScrutinizer05http://www.youtube.com/watch?v=b9FC9fAlfQE&noredirect=121:17
DocScrutinizer05highly recommended!21:17
DocScrutinizer05that guy is not telling bullshit21:18
DocScrutinizer05apelete: this is no sarcasm or kidding, just a honest friendly suggestion: get a raster PCB ( http://www.strippenstrolch.de/1-1-3-die-lochrasterplatine.html ) and practice a little, soldering wires to the holes21:28
apeleteDocScrutinizer05: that's a nice idea indeed. shouldn't be expensive on eBay (raster PCB + a few cheap components and wires)21:34
DocScrutinizer05wow! https://github.com/mpue/blackboard21:44
wpwrakapelete: (magnifying glasses) hmm, can't hurt to have something for examination. but for working they're probably too inconvenient because you have to adjust things, move them around, etc.22:54
wpwrakbut for looking at it when done, to see what you did, why not. or get any other good magnifying glass. or, if you get a lab lamp, these often have built-in magnifying glasses22:55
wpwrakthis kind: http://www.howardelectronics.com/HEIScope/illumination/magnifier.html22:55
wpwraka strong light source often works wonders22:55
apeletewpwrak: these are nice, and you're right about the inconvenience of having to adjust things while working. a lab lamp w/ magnifying glass should be perfect23:00
DocScrutinizer05wpwrak: 160 bucks? ESD save 190 bucks???23:26
DocScrutinizer05WTF?23:27
wpwrakDocScrutinizer05: i didn't say he'd have to order from there :) i'm sure there are cheaper sources ...23:28
DocScrutinizer05and particularly sources who not charge an extra 30 bucks for a wire23:28
wpwrakDocScrutinizer05: i'm sure you can dig out something cheaper from pearl.de or such :)23:34
DocScrutinizer05yeah, sure23:34
DocScrutinizer05I was just stunned by their 30 bucks for "ESD safe"23:35
DocScrutinizer05an excellent example why "when you find this cheaper anywhere, we will adjust our offer to beat them" actually means "we're perky in prices but who cares, we're selling nevertheless"23:36
wpwrak"ESD safe" may also have some conductive coating and such. or simply come from a more expensive company.23:57
wpwrakor maybe it comes with a cool certificate. certificates are $$$ ;-)23:58
--- Mon Feb 24 201400:00

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