Speaking as someone with two 3D printers (A Robo 3D R1+ and a Printrbot Simple Metal), I think I can speak a little to this. I have printed some D&D minis and some terrain, to varying effect. I'll try not to go overboard.
There are several advantages and disadvantages to 3D printing minis. First, lets break 3D printing down into constituent technologies, specifically FDM, SLA/DLP and Sintering. Without going into too much detail, most 3D printers are FDM, which deposit heated plastic onto a bed, one layer at a time; SLA/DLP uses a liquid resin that is solidified by a laser, again one layer at a time; Sintering takes a fine powered material and applies a glue-like substance to it or uses a laser to fuse it, again, one layer at a time. So 3D printing creates very thin slices of an object, stacking them until you have the object. That's important because it is a limitation of the technology; there are work-arounds, but certain designs are more difficult compared with mold-casted miniatures.
Here's a few things to understand.
- 3D Printing is expensive
- 3D priting is not a turnkey solution
- There are many, MANY free designs out there
- Different technologies provide different advantages/disadvantages
- 3D printing is SLOW
- Quality requires time and/or money
- Physics can be your enemy when printing
This may sound like I'm telling you this can't be done. I'm not. It totally can. HOWEVER. If you are thinking, '
Wow, I'll just drop $150 on Monoprice and get a printer and I'll be printing orc armies is no time!' that you may need to reset your expectations some. While it has much improved since I started using printers 3 years ago, it is still very much a hobbyist pursuit, like a HAM radio or car tuning. My first printer took me 6 hours to get a print out of (including printer assembly and fine-tuning). My second printer I had going in 45 minutes...but that was a more expensive unit. Regardless, simply be aware that even when you get it running, there will be a lot of tinkering to get your unique settings right for your environment (based on your material, humidity, printer and lots of factors).
Now let's talk the real issues: quality. FDM printers, out of the box, usually only support a print 'resolution' of 100 micrometers (.1MM). That sounds super small, and it is, BUT...when printing a 28MM scale miniature, it is not as small as it sounds. This means your mini may have visible lines for each layer as it prints, possibly preventing the high-level of detail you may be expecting from a molded mini. SLA/DLP printers can go down to 25 micrometers, which as you might expect leads to very high detail...but SLA/DLP printers are much more expensive (I have a friend who has a FORM 2...it retails currently for $3500) and require things like cleanup and curing. In terms of time, for me to print a miniature from HeroForge can take from 3 to 4 hours, depending on the design and resolution. Also, depending on the design, it may not be a simple issue to print it. Characters with out-stretched limbs, for example, require you to print support structures for those limbs to be printed properly (as you can start printing a layer in mid-air).
Now, having said all of that, I can assure that you can do it, it's fun and it's quite possible to get very nice results. I will gladly go on more detail about the topic, share pics of what I've printed and so forth. I've printed some very cool dungeon tiles, for example. But I wanted to let you know you're essentially adopting a hobby to do it and that you're not going to push a button and get a beholder (which is a nightmare to print, btw). There are limitations to what it can do and what it can do EASILY, but the results can be great.