I've been somewhat fascinated with 3D printing ever since becoming aware of it a decade ago, but it was prohibitively expensive to get into it when machines were in the four-digit USD$ range and seemed likely to be limited to somewhat-unreliably producing useless tchotchkes at vastly higher cost. Things have changed. A lot.
Declining costs
Cost of entry
My new(ish) printer is the Cocoon Create Modelmaker, a respin/reskin of the Wanhao i3 Mini - which if you follow the links, you'll note is USD$199 brand new, but I got mine second-hand on eBay for AUD$100. I'm a sucker for an eBay bargain. When I picked it up, the seller (who was upgrading to a model with a larger print bed) also gave me a crash course in printing and then threw in an almost-full 300m spool of filament to get me started - another AUD$20 saved. So I'm already at the f*@k it point as far as up-front investment goes.
Cost of materials
I'm picking up 300m rolls of PLA filament from eBay for AUD$20-$24 delivered, and I'm choosing local suppliers so they typically get delivered within 3 days. I could go even cheaper if I used Chinese suppliers. The biggest thing I've printed so far was a case for my Raspberry Pi 3B+, part of a 19" rack mount setup (I'm also a sucker for anything rackmounted) - that took 21 hours and used about 95c of filament. So really, it's starting to approach "free to make" as long as you don't place too much value on your own time...
Damn Fine Software
Seven years ago, Scott Hanselman documented his early experiences with 3D printing; there was a lot of rage and frustration. Maybe I've just been lucky, maybe buying a printer that had already been used, tweaked, and enhanced (with 3d-printed upgrade parts) was a galaxy-brain genius move, but honestly, I've had very little trouble, and I'd estimate less than 50c of material has ended up in the bin. Happy with that. I think the tools have moved on supremely in that time, and awesomely, they're all FREE and most are also Open-Source.
Cura
Ultimaker Cura takes an STL file and "slices" it into something your actual hardware can print, via a G-Code file. It's analogous to the JVM taking generic Java bytecodes and translating them to x86 machine language or whatever. Anyway, it does a great job, and it's free.
OctoPrint
My first 3D printing "toolchain" consisted of me slicing in Cura on my Mac followed by saving the file to a micro SD card (via an adapter), then turning around to place the (unsheathed) micro SD card into my printer's front-panel slot, and instructing it to print. This was fine, but the "sneakernet"-like experience was annoying (I kept losing the SD adapter) and the printer made a huge racket being on a table in the middle of the room. Then I discovered OctoPrint, an open-source masterpiece that network-enables any compatible 3D printer with a USB port. I pressed my otherwise-idle 5-series Intel NUC into service and it's been flawless, allowing me to wirelessly submit jobs to the printer, which now resides in a cupboard, reducing noise and increasing temperature stability (which is good for print quality)
Tinkercad
It didn't take long for me to want a little more than what Thingiverse et al could provide. Thingiverse's "Remix" culture is just awesome - a hardware equivalent to open-sourced software - but my experience of CAD was limited to a semester in university bashing up against Autodesk's AutoCAD, so I figured it would just be too hard for a hobbyist like me to create new things. Then I discovered Tinkercad, a free web application by, of all companies, Autodesk! This app features one of the best tutorial introductions I've ever seen; truly, I could get my 10-year old daughter productive in this software thanks to that tutorial. And the whole thing being on the web makes it portable and flexible. Massive kudos to Autodesk for this one.
Do It
The useless tchotchke era is over; I've been using my printer to replace lost board game tokens, organise cables, rackmount loose devices, and create LEGO parts that don't exist yet. As far as I'm concerned it's virtually paid for itself already, and I'm still getting better as a designer and operator of the machine. If you've been waiting for the right time to pounce, I strongly recommend picking up a used 3D printer and giving it a whirl.
