So actually a fair few years back now every popular science, weekend DIY, maker and whatnot rag was littered with articles on 3d printers and how they were the future While I am... OK always one to point and laugh at a fad they had just about crashed into a reasonable price range (possibly with the end of some patents) and usability had sort of got somewhere (more on that later). Today is the future and I don't see one in every home like some predicted (that may still be a while off) but they do seem to be in places that you might not expect. For my money I would still get myself a CNC milling machine and hope I live somewhere that has a nice plastics shop (was in the US and got to go into a TAP plastics...) but the case for the 3d printer has never been stronger.
For those new to it all. 3d printers are much as they sound and print things in 3d space out of... typically a type of plastic but metals, ceramics, sugar and meat are variously options in this.
Back then the ones most were looking at were FDM (fused deposition module). This is what you will typically see with reels of filament (very occasionally granules), these days things even having multiple feeds, through a hot nozzle.
Laser curing/photo curing became a thing a few years ago. The principle existed for many years (the STL files that are the standard for 3d printing are short for stereo lithography) but generally you get a very expensive liquid you pour into a tank that a laser or UV diode is guided over and it feeds down and down such that layer by layer you get a finished product. Surface finish out of the box on these is fantastic and is probably going to destroy the model kits industry (from warhammer on down) in a few years, indeed nerd shops not tooling up for it are generally said to be missing a trick. Materials are a bit more limited but not that bad and mechanical results are also often superior to FDM. Main limiting factor is the size you can print (you have to contain a liquid after all).
SLS aka selective laser sintering has hit serious hobbyist price range. If you were considering a serious workshop then $10000 and a lot of work will get you a kit for it, more turnkey industrial are still several times that at least but dropping fairly fast as well ($100000 was entry level until somewhat recently). For those unaware this takes powder, scans a laser across it such that it melts together and thus layer by layer you have your thing. Quality is almost injection moulded (but with the near impossibility options 3d printers afford like enclosed hollow spaces), certainly better than bad injection moulding. Speed is considerable (low volume production quite happily). Operating costs are quite expensive as well -- you can reuse the powder if you mix it down with fresh a few times maybe but... yeah. Never the less king of the 3d printing jungle and will be until someone sorts an injection moulding die making setup (and home made EDM is super near as well).
Something you might have missed
If your familiarity with the matter comes from those early FDM printers (or even worse "cheap" ones of those -- still would have been several hundred dollars at the time, ones that would really work for a complete newbie to it all being possibly multiple times that further) then you might want to revisit the matter. Early ones worked but today the software is better, the temperature control is orders of magnitude better (eliminating a lot of difficulties people faced), heated beds have come a long way, the stability/accuracy is higher and much more besides to make things actually work like people want. Some of the better options might even include optical recognition options to make things even fancier still. Engineering CAD and CAM is still going to be difficult if you have never done it or even much engineering drawing before, which was a major stumbling block for a lot of people as it is not necessarily an intuitive process, but there are options there as well -- sketchup has since been sold by Google but has gone from strength to strength in terms of usability ( https://www.sketchup.com/plans-and-pricing/sketchup-free , or maybe http://www.oldversion.com/windows/google-sketchup/ ), and I have found some people take to https://openscad.org/ really well which shocked me but is what it is.
Old but still nice overview of sketchup
OpenSCAD https://openscad.org/
and if nothing else you don't need to roll your own as someone probably did stuff you would be interested in
https://alternativeto.net/software/thingiverse/
If pondering the merits of such things
So then do you have a 3d printer? Do you use it often? Do they have ones in your school? Do they have one in the local library (I went on one somewhere I used to live, they had several quite nice ones but nobody that knew how to run them)? Even if you don't use it often does it come in handy for little things that might have seen you have to chuck something or do extensive/expensive repairs before? While primary operations never quite made that "it is like the replicator on Star Trek" level do you find yours useful as a stage in making something rather than the end goal (metal 3d printers might be expensive, using it as an investment casting mould... well now)?
For those new to it all. 3d printers are much as they sound and print things in 3d space out of... typically a type of plastic but metals, ceramics, sugar and meat are variously options in this.
Back then the ones most were looking at were FDM (fused deposition module). This is what you will typically see with reels of filament (very occasionally granules), these days things even having multiple feeds, through a hot nozzle.
Laser curing/photo curing became a thing a few years ago. The principle existed for many years (the STL files that are the standard for 3d printing are short for stereo lithography) but generally you get a very expensive liquid you pour into a tank that a laser or UV diode is guided over and it feeds down and down such that layer by layer you get a finished product. Surface finish out of the box on these is fantastic and is probably going to destroy the model kits industry (from warhammer on down) in a few years, indeed nerd shops not tooling up for it are generally said to be missing a trick. Materials are a bit more limited but not that bad and mechanical results are also often superior to FDM. Main limiting factor is the size you can print (you have to contain a liquid after all).
SLS aka selective laser sintering has hit serious hobbyist price range. If you were considering a serious workshop then $10000 and a lot of work will get you a kit for it, more turnkey industrial are still several times that at least but dropping fairly fast as well ($100000 was entry level until somewhat recently). For those unaware this takes powder, scans a laser across it such that it melts together and thus layer by layer you have your thing. Quality is almost injection moulded (but with the near impossibility options 3d printers afford like enclosed hollow spaces), certainly better than bad injection moulding. Speed is considerable (low volume production quite happily). Operating costs are quite expensive as well -- you can reuse the powder if you mix it down with fresh a few times maybe but... yeah. Never the less king of the 3d printing jungle and will be until someone sorts an injection moulding die making setup (and home made EDM is super near as well).
Something you might have missed
If your familiarity with the matter comes from those early FDM printers (or even worse "cheap" ones of those -- still would have been several hundred dollars at the time, ones that would really work for a complete newbie to it all being possibly multiple times that further) then you might want to revisit the matter. Early ones worked but today the software is better, the temperature control is orders of magnitude better (eliminating a lot of difficulties people faced), heated beds have come a long way, the stability/accuracy is higher and much more besides to make things actually work like people want. Some of the better options might even include optical recognition options to make things even fancier still. Engineering CAD and CAM is still going to be difficult if you have never done it or even much engineering drawing before, which was a major stumbling block for a lot of people as it is not necessarily an intuitive process, but there are options there as well -- sketchup has since been sold by Google but has gone from strength to strength in terms of usability ( https://www.sketchup.com/plans-and-pricing/sketchup-free , or maybe http://www.oldversion.com/windows/google-sketchup/ ), and I have found some people take to https://openscad.org/ really well which shocked me but is what it is.
Old but still nice overview of sketchup
OpenSCAD https://openscad.org/
and if nothing else you don't need to roll your own as someone probably did stuff you would be interested in
https://alternativeto.net/software/thingiverse/
If pondering the merits of such things
So then do you have a 3d printer? Do you use it often? Do they have ones in your school? Do they have one in the local library (I went on one somewhere I used to live, they had several quite nice ones but nobody that knew how to run them)? Even if you don't use it often does it come in handy for little things that might have seen you have to chuck something or do extensive/expensive repairs before? While primary operations never quite made that "it is like the replicator on Star Trek" level do you find yours useful as a stage in making something rather than the end goal (metal 3d printers might be expensive, using it as an investment casting mould... well now)?