Guess all depends on budget, project, intent, and profession.
Like most 'making' tech with 'pro-sumer' options, I think in time it'll get to inkjet on every desk type of world, once the price pt. falls below $500. Already, there's one for $600.
Say I'm working on a R/C plane or car, can mill the chasis or frame out of aluminum with DIY home mill (CNC or manual) for less than $1000 to $5000, buy plastic 3D printer for $600 to 'print' the body, or wing, etc.
Those like MakerBots, the printer will be able to 'upgrade' to next version, by printing itself an updated part.
Now of course not all will be DIY, but there's enough market viability for those looking to do more professional prototyping, such as in your field, to hobbyists, to eventually casual tinkerers, like all tech.
If you deal in prototypes, as you know, there are several types of 3D printers: stationary platform+'elevator' printheads, elevator platform+stationary printheads, elevator platform+elevator printheads, old school laser-3D stereolithography, there are even 3D metal printers.
Obviously, it'll be a longtime before there will ever be a 3D metal-printing technology that can match billet/forging strength, but MIM level standard probably won't be that far off IMO.
Hey, who knows, perhaps advances in affordable graphene/carbon nanotube printing (right now $100,000~$5mil + highly attuned specialized kiln) will happen before 3D metal printing tech advancements, and the question will become moot.
As for recycling left overs, not sure if they have reclaiming services particularly geared toward 3D printed scraps, right now.
That said, despite the fact that there are many more varieties of printable plastics than just the ABS, and while plastics are more of a 'recipe' than homogenous, I do know that ABS is recyclable. Not sure if its characteristics pre vs. post recycle will be the same.
You can YouTube 3D printers and the more professionally geared ones, there are some that even approach acetal resin in strength. And some can print multi colored moving parts like helical gears, together! But those are done in like 'sand bath.'
Other than for high stress applications, I'd project that the future of consumer product manufacturing is in 3D printing; soon you'll be able to integrate electronic circuits into the plastic bodies as they're being printed! And who knows, even 'printed' carbon-nanotube batteries.
There are even 3D concrete printers: https://www.youtube.com/watch?v=EfbhdZKPHro
The future for the tech is endless.
So I suppose for those who regularly work with Haas CNC, or Bridgeport in engineering fields, or motosport design where current slate of 3D printers are really more for rapid-prototyping, eventually, polymer tech and recipe will be such that I can extrapolate in 10yrs (if currency collapse don't destroy everything first), other than high stress metallurgy only or conductive applications, polymers would probably dominate most structural component applications for most non-high volume consumer products.
as you know, tooling costs money. so for outside of mass assembly, for limited run, out of production, bespoke/custom parts, 3D Printing is the future.
While not strictly 3D Printing, per-se, but related, Jay Leno actually uses 3D scanners in combo with rapid-prototyping to make out production parts for his auto collection:
Check some of these out:
3d Printing moving parts
Predictions in due Time...
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