#qi-hardware IRC log for Friday, 2014-08-08

whitequarkwpwrak: btw, remember my order of extra-thick acrylic? it arrived finally13:16
whitequarkalthough I suddenly realize I don't have anything to cut 1" acrylic horizontally with13:17
whitequarkthis book about PCBs I bought is very interesting. I see it has a chapter on Laser Direct Imaging13:49
whitequarkso I'm trying to lubricate the linear bearings with this PTFE-based lubricant, nonviscous and inert15:00
whitequarkin principle, the best one for this task15:00
whitequarkand they start to work significantly *worse*15:00
whitequarkhm, odd17:50
whitequarkafter assembling it back, it works pretty smooth17:50
DocScrutinizer05odds are the bearings are already made of PTFE, then you just ruined them by basically dissolving the b earing with the lubricant18:03
whitequarkDocScrutinizer05: huh?18:04
whitequarkthey are absolutely not, and if they were, that would not be the case18:04
whitequarka PTFE lubricant is an emulsion of PTFE in some kind of oil18:04
DocScrutinizer05while I dunno for sure if this is true for PTFE, it is definitely true for using mineral oil based lubricants on usual oil based plastics18:04
whitequarkit's not corrosive nor a solvent18:04
whitequarkyes. for mineral oil plastics, this is true.18:04
whitequarkbut not for PTFE. I do have a lubricated PTFE part there, and it came from a factory lubricated with PTFE, and I used it for half a year18:05
whitequarkstill it is pretty much intact18:05
whitequarkthe bearings are LM22UU18:05
DocScrutinizer05then nevermind what I said18:05
whitequarksteel balls inside some kind of regular shitty plastic case18:05
Action: DocScrutinizer05 wonders if can copy the URL via VNC to local browser18:06
whitequarkdon't bother18:06
whitequarkthe page is very uninformative18:06
DocScrutinizer05anyway IT WORKS \o/18:07
DocScrutinizer05hal VNC18:07
DocScrutinizer05that's really awesome and amazing18:08
whitequarkso, yeah, I first soaked them with dimethoxymethane aerosol to clean grit that was definitely inside18:08
whitequarkI know because when the liquid dried, there was shit all over my floor18:08
whitequarkit made them roll somewhat better18:08
DocScrutinizer05almost lets me forget the tooth I just broke. 2nd in 3 weeks18:08
whitequarkthen I put a LOT of liquid PTFE-based lubricant inside18:09
whitequarkwhen I tried to manually move the rod, it still didn't move smoothly at all18:09
whitequarkbut when I actually assembled it all on the machine frame, it seems to run quite well18:09
whitequarkmuch better than before, at least18:09
whitequarkI don't know if it's shitty bearing design or merely shitty broken bearings that I now have18:10
whitequarksince the balls basically ground several depressions in the hardened chrome-plated rods18:10
whitequarkthere could be literally anything wrong with the bearings18:10
whitequarkthey aren't *supposed* to do that18:10
DocScrutinizer05considered acrylic dust getting dissolved in your solvent?18:10
whitequarkno, the bearings are closed, and there was no workpiece material inside18:11
whitequarkalso, dimethoxymethane is sold as PCB cleaner, specifically because it doesn't dissolve plastics18:11
whitequarkyou don't want a connector to mangle while you clean it18:11
whitequarkhowever it is really good at removing various kinds of organic residue18:12
Action: DocScrutinizer05 heads out again, too get some USB extension so can put the N900 on the balcony and *maybe* get more than 6KB/s from 3G18:12
whitequarkso that's what I thought, the pressurised stream of dimethoxymethane should dissolve any sticking stuff and get the grit out of bearings18:12
DocScrutinizer05fsck dentists, they got no clue really18:14
DocScrutinizer05I mean, when you mill out everything but a 0.5mm thick wall from a cylindricaloid object made of calcium and fill that cavity with epoxy, what do you expect the calcium wall being able to take on mechanical force before it breaks18:17
whitequarkshould've got an implant, no?18:18
DocScrutinizer05sort of18:18
DocScrutinizer053 weeks ago right lower 7 broke, now left lower 7 same18:19
whitequarkthat sucks :/18:19
DocScrutinizer05particularly since detinst "fixed" both less than a year ago, and already fixed the very same problem on left lower a 2 weeks after original work. And that shit cost me 150018:21
DocScrutinizer05that dentist is not worth her money18:22
DocScrutinizer05I wonder if there shouldn't be warranty on craftmanship for dentist work as well18:23
whitequarkI think there is?18:23
DocScrutinizer05on the bright side: it could be worse. both teeth are dead - complete radix nerve removal - iirc18:24
DocScrutinizer05so at least no pain, except from sharp edges cutting my tongue18:25
DocScrutinizer05in holiday18:25
DocScrutinizer05probably you and me both would be the better dentists than this lady. We understand our materials and glue and stuff, right? ;-D18:27
wpwrakyou may want to go to a local dentist to get a temporary filling. that'll be good for some weeks.18:27
wpwrakthat way you won't cut yourself on sharp edges18:29
DocScrutinizer05it's only 10% of the active surface that's missing now, and I'm afraid some more provisional messing with this tooth will ruin the radix treatment which so far acts fine18:29
whitequarkoooh yes, sharp edges cutting the tongue. I understand you so well18:29
Action: DocScrutinizer05 gets a decent glass of Terry Centenario to forget that shit18:31
larscwhitequark: always swallow your razors whole18:32
wpwrakalso, do not run your chainsaws at excessive speed while juggling them18:57
DocScrutinizer05I guess what broke away isn't tooth calcium but already some epoxy or acrylate she used last time she tried to fix exactly same issue: http://maemo.cloud-7.de/share-service/20140808_012.jpg19:03
DocScrutinizer05so trying to get this simply replaced by another blob of acrylic putty might not be the worst idea indeed19:07
whitequarkI would use single-component epoxy though, it seems sturdier to me19:08
DocScrutinizer51I dunno what they use in dentistery nowadays19:09
whitequarkcould ask pubmed?19:09
DocScrutinizer51prolly mostly cyanoacrylate with UV curing19:10
DocScrutinizer51some harvard shit19:10
DocScrutinizer51some of the stuff is mildly biozid so can't get used every case19:11
whitequarkmmm, cyanoacrylate19:13
whitequarkUV curing? I thought cyanoacrylate curing is catalyzed by water vapour19:13
wpwrakprolly some plastic-ceramic mix. and yes, everything with uv curing.19:15
wpwrakthat is, unless it's somewhere inaccessible. then they switch to some concrete19:15
wpwrakyes ! ubuntu updates chromium to a version without the http://-stripping bug. FINALLY !19:21
Action: eintopf reminds me of the firefox stealing focus bug19:48
eintopfabout years, firefox switching virtual desktop if you opened a url19:49
fmeerkoetterI didn't fully grok http://en.qi-hardware.com/wiki/Ben_WPAN - is it currently possible to buy ATUSB devices? 20:45
wpwrakhow to get rid of telemarketers: https://plus.google.com/+ChrisBlasko/posts/GzCuzTyUXNq22:08
--- Sat Aug 9 201400:00

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