<wpwrak>
interesting: someone figured out how to make stereolithography very inexpensive: http://www.peachyprinter.com/
woakas has quit [Ping timeout: 245 seconds]
<wpwrak>
he needs to get an MCU, though :)
<whitequark>
really interesting
<wpwrak>
i 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.
<wpwrak>
so the salt water must play a role in this. i wonder if it's chemical, optical, or maybe both.
<wpwrak>
i would suspect chemical
<ysionneau>
for those interested, the princeton university free course (coursera) about Computer Architecture is starting again this year today
<wpwrak>
might 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.
<whitequark>
wpwrak: (sources) as in vendors?
<ysionneau>
if 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-002
<ysionneau>
</spam>
<wpwrak>
whitequark: yes
<wpwrak>
whitequark: 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 restrictions
<whitequark>
wonder if it's possible to develop some sort of "open-source resin"
<wpwrak>
maybe 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)
<wpwrak>
shrinkage, thermal runaway, etc., probably aren't much of an issue in such an application. the smell may still be, though.
<wpwrak>
anybody here who knows something about chemistry ? :)
FDCX has quit [Ping timeout: 276 seconds]
<wpwrak>
hmm, polyester resin .. 1.12 g/cm3. heavier even than heavy water
<roh>
wpwrak: crazy printer
<roh>
dead cheap concept.. but doesnt look that easy to use and run (reliably)
<whitequark>
wpwrak: i wonder how much is "something"
<wpwrak>
roh: 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 point
<wpwrak>
roh: to calibrate Z, assuming you have uniform drops, you'd want a sensor to measure at least two (low) points of the fluid level
<wpwrak>
and maybe add an acceleration sensor to stop the laser when there is vibration
<roh>
wpwrak: something like that. atleast... anyhow.. nice demonstration of a lowest possible end
<roh>
still impressive
<wpwrak>
very. 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 coils
<roh>
there is a guy in #linuxcnc or #reprap who said its only 20-30$ per litre
<roh>
50-60us$ a gallon afaik... the question is rather which exact resin you want. there are different ones by wavelength etc
<wpwrak>
(touch id) yeah :) impressively fast
wej has quit [Ping timeout: 245 seconds]
<wpwrak>
roh: 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.
wej has joined #qi-hardware
<wpwrak>
yeah. 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.
<wpwrak>
kewl. almost reverse-engineered it already :)
<roh>
yep.. you make 'support' struts to bind the object to the surface, which you cut up afterwards
<wpwrak>
yes, that too. but what i meant was the initial platform you start building on.
kilae has quit [Quit: ChatZilla 0.9.90.1 [Firefox 24.0/20130910160258]]