#qi-hardware IRC log for Monday, 2013-09-23

DocScrutinizer05well, the latter is quite normal nowadays02:08
kristianpaulha nice (wheel), that remenber me a thermostate i saw recently :)03:51
whitequarkso I've finally got around to bringing up these boards we made03:53
whitequarkout of 5 boards we've tried to assemble, 3 lived03:53
whitequarkout of these, two have dead displays, and the remaining one a broken button03:54
whitequarkin other words, a totally normal batch :D03:54
wpwrakmaybe you should stop buying military surplus components :)05:21
wpwrakgrmbl. blackout .. again :(14:31
larscwas wondering way I was only reading garbage, was sending a signal with the same frequence as the the ADC sampling rate, nobody beats nyquist15:14
wpwrakheh :)15:14
sendakhi, anyone knows where to get a nanonote?18:39
kyakyou'd be lucky to still be able to get it18:42
kyakmeaning i'm not pulster still has them18:43
kyak*not sure18:43
kyakhttp://www.openmobile.nl/ - not sure about this one18:44
kyakbut you might ask18:44
wpwrakinteresting: someone figured out how to make stereolithography very inexpensive: http://www.peachyprinter.com/19:06
wpwrakhe needs to get an MCU, though :)19:22
whitequarkreally interesting19:29
wpwraki wonder what effect creates the solidification. it can't be just light plus resin, since that would yield flakes on the top or maybe little fibers/sticks in the resin layer.19:46
wpwrakso the salt water must play a role in this. i wonder if it's chemical, optical, or maybe both.19:47
wpwraki would suspect chemical19:48
ysionneaufor those interested, the princeton university free course (coursera) about Computer Architecture is starting again this year today19:53
ysionneaufor those who missed it last year :)19:53
wpwrakmight be fun to find a cheap resin mix. one big problems of all those 3D printers is that you have only a small number of sources for materials. for stereolithography, that number tends to be one.19:53
whitequarkwpwrak: (sources) as in vendors?19:54
ysionneauif you want, you can download the texts and videos automatically by using the coursera-dl tool (git clone git://github.com/jplehmann/coursera.git && cd coursera && ./coursera-dl -u login -p password comparch-00219:54
wpwrakwhitequark: yes19:55
wpwrakwhitequark: because each has their own secret mixture. and then you have fancy chemicals that a) are expensive to ship around the globe, and b) may run into all sorts of export/shipping/import restrictions19:57
whitequarkwonder if it's possible to develop some sort of "open-source resin"19:58
wpwrakmaybe one could cook something with polyester resin. that stuff is very cheap and you can find it everywhere. you need something that sets off radicals when illuminated. that's called the "catalyst" (though, according to wikipedia, it doesn't work that way)19:59
wpwrakshrinkage, thermal runaway, etc., probably aren't much of an issue in such an application. the smell may still be, though.19:59
wpwrakanybody here who knows something about chemistry ? :)20:04
wpwrakhmm, polyester resin .. 1.12 g/cm3. heavier even than heavy water20:09
rohwpwrak: crazy printer20:13
rohdead cheap concept.. but doesnt look that easy to use and run (reliably)20:13
whitequarkwpwrak: i wonder how much is "something"20:13
wpwrakroh: it may not be so bad. you could calibrate X/Y by simply having two (or maybe more) marked points and manually tuning the volume such that the laser hits the point20:15
wpwrakroh: to calibrate Z, assuming you have uniform drops, you'd want a sensor to measure at least two (low) points of the fluid level20:16
wpwrakand maybe add an acceleration sensor to stop the laser when there is vibration20:16
rohwpwrak: something like that. atleast... anyhow.. nice demonstration of a lowest possible end20:16
rohstill impressive20:17
wpwrakvery. if we can find a resin, it may not be so hard to copy that design. considering the idea of using audio for control, maybe a (small) loudspeaker could provide suitable coils20:22
Action: roh is watching the madness-wake...20:22
rohthere is a guy in #linuxcnc or #reprap who said its only 20-30$ per litre20:23
roh50-60us$ a gallon afaik... the question is rather which exact resin you want. there are different ones by wavelength etc20:24
wpwrak(touch id) yeah :) impressively fast20:24
wpwrakroh: i wonder how you make it solidify at the right place. well, thinking of it, you could actually do that at the top as well, not at the resin-water barrier. 20:26
wpwrakyeah. that's the most likely explanation. have a structure that's above the initial resin level. then add water until the resin starts to cover that platform. there, you begin lasering.20:27
wpwrakkewl. almost reverse-engineered it already :)20:27
rohyep.. you make 'support' struts to bind the object to the surface, which you cut up afterwards20:31
wpwrakyes, that too. but what i meant was the initial platform you start building on.20:33
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