On Tue, May 11, 2010 at 12:56 AM, Dr. H. Nikolaus Schaller <h...@computer.org> wrote: > has fixed dimensions) and we can't afford to build plastic injection > moulds (if someone has an idea how to reduce cost this is very > welcome). So the easiest solution was to combine what we have: a given > Beagleboard and the Freerunner case.
Personally I don't see what the big deal is with mold-making. Anybody could start a business doing that if it's so lucrative: get a Harbor Freight or other cheap milling machine and some blocks of aluminum, and develop the skill to do sufficiently accurate machining. (I have tried a little milling but my skill level definitely needs a lot of improvement; maybe it will if I ever get around to doing enough of it.) Of course CNC would be nice, but again, what's the big deal...3 steppers or servo motors and a controller... As someone else mentioned the Chinese obviously aren't having too much trouble with mold-making. It's also within the realm of possibility to make your own injection molding machine. There is a book (Gingery) about how to do that, but there is nothing too exotic in that book either... it's just a heated cylinder and piston arrangement with a lever to apply the pressure. Hot plastic comes squirting out, and you have your mold clamped in place to receive it. Alternatives include building a RepRap, making the plastic parts directly, and putting up with rough, inaccurate results; buying a better rapid prototyping machine (FDM type or laser sintering or the type that builds up parts from thin laminates); or directly CNC-milling the cases (you could even use wood then). As a DIY/hacker type thing rather than commercial, it might fly. Maybe try to get a story in Make Magazine because there seems to be a trendy new crowd of DIY/hacker types nowadays, who weren't around a couple years ago. Or get it made at one of the rapid-prototyping shops. For every type of RP technology there are multiple shops doing on-demand prototypes. In any event, the case design could be posted on http://www.thingiverse.com/ and maybe someone who has a RepRap or similar can try to make a prototype. There was a design contest going on but I guess the time has passed: http://blog.makezine.com/archive/2010/04/makerbot_giveaway.html _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
