Injection molding is on the order of 10,000x more expensive if you only need a single part.
I'm currently on a quest to design highly functional robots that can be made with just a 3D printer and a minimum of external parts - so far only bearings, motors, drive belts, batteries and electronics are the non-printed parts needed. I make everything so that it fits together by interlocking or with minimal use of some coarse printed fasteners.
Since nothing needs to be bought from the store that won't be useful if the design changes, it is trivial to iterate and build a newer version.
My hope is that with developers worldwide working on improvements, injection molded versions of the parts would become obsolete before the mold was even cut.
When it comes to manufacturing, 3D printing is a whole different ballgame. No other manufacturing technique can make so many complex parts without human intervention. This means it opens up all new possibilities for how we manufacture things - like continuous iteration of shipping hardware.
Well, parts made in a powder bed printer don't typically have nearly as much grain, if any. I'm a big fan of that style printer in the future, so one solution to the problem is to use those instead.
For typical FDM/FFM printers like the hobby ones you see everywhere, there are chemicals that can be used to smooth the print out.
I use my parts for robot prototypes where the function of the part is more important than cosmetics, so I don't worry about the grain. If I want a nice part though, I can use very fine layers.
that is a horrible article, considering the picture they are using is ripped off of a reprap blog on smoothing abs prints using acetone vapors. http://blog.reprap.org/2013/02/vapor-treating-abs-rp-parts.h.... (I'm actually a member of Fablocker, so I'd seen those squirrels before)
on that note though, from my experiments, acetone vapor bath does seem to strengthen abs prints some, cause it melts the surface together. Not terribly big effect, but it actually helps a lot for low infill parts and stuff.
You can give the parts a vapor bath, but you lose some of the exactness. The longer you do it the smoother the part but the more it loses it's dimensions. You are basically melting the plastic with fumes.
I'm currently on a quest to design highly functional robots that can be made with just a 3D printer and a minimum of external parts - so far only bearings, motors, drive belts, batteries and electronics are the non-printed parts needed. I make everything so that it fits together by interlocking or with minimal use of some coarse printed fasteners.
Since nothing needs to be bought from the store that won't be useful if the design changes, it is trivial to iterate and build a newer version.
My hope is that with developers worldwide working on improvements, injection molded versions of the parts would become obsolete before the mold was even cut.
When it comes to manufacturing, 3D printing is a whole different ballgame. No other manufacturing technique can make so many complex parts without human intervention. This means it opens up all new possibilities for how we manufacture things - like continuous iteration of shipping hardware.