On Tuesday 07 August 2012 02:32:47 cogoman did opine: > On 08/06/2012 09:49 PM, Jon Elson wrote: > > I make my own stencils for these. It is kind of a pain, but I'm > > CHEAP! > > How about the cheapest CNC to build, an XY plotter like this: > > https://www.youtube.com/watch?v=WyLPpGdfR7s
That seems to be pretty sloppy, with pen tilt being a major problem. In addition to that, a 3rd tension pulling down would reduce the positioning errors from the sag in the upper support lines. Ok for crayon on the wall art, but obviously very slow. > but with the laser from an old DVD burner for the pen. You could > produce plotter output files and convert them to G-code, and then cut > them out of thin plastic (just shield your eyes while it runs, or box it > in. Could one use the resultant laser cut stencil as if it was a silk screen to apply the solder paste? If so, that would certainly cut large hunks of time out of the process once the stencil was made. However, having the paste exposed to the air while on the stencil would make me want to figure out a way to flood the area with GN2 to slow the oxidation that would occur while doing the time consuming pick-n-place, and on to the reflow oven. All of that should be in an oxygen free atmosphere to preserve the solder ability. Quality wise there probably would be a better flooding gas than GN2, but GN2 is relatively cheap. > Getting the tool set in line would take some time, but once you get > the hang of it, it would save time in the long run. > Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) My web page: <http://coyoteden.dyndns-free.com:85/gene> is up! I've finally learned what "upward compatible" means. It means we get to keep all our old mistakes. -- Dennie van Tassel ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
