You all are missing the point.
3D printer to do more than just make AR Lowers. You know, to play with.
Plus we have a ton of aluminum... and are going to build this foundry: https://www.youtube.com/watch?v=hHD10DjxM1g
So it's more then just lowers. We will probably make other "stuff" with both...
The Chicom Anet a6 could easily churn out a lower. And if you want to cast your own Al ones a 3D printer is the way to go, because you're going to want to make it about 2% oversized for the nominal shrinkage of cast metal. You can even make it real thin with just minimal honeycomb inside so it prints quicker and uses less filament. You can even just put your mold in a hot fire and burn all the plastic away, and in CAD you can stick whatever kind of sprue funnels and vents you need to right onto the model.
I just moved mine from the dining room table and to it's more or less permanent home in the workshop battlestation. The only space I had for it was one of those crappy plastic shelves which had some sag to it. So today I bought a 1/8" sheet of masonite so there was a solid surface covering the grid of plastic slats. Then I put a heavy 3/4" thick board of MDF over that, but first I put several felt pad screw feet into it so I could level it, then checked with a little machinists bullseye bubble level and a stick level. If you've got a good level place to put it, that much effort isn't required, but it will make the printer a bit quieter, because all the whining of the stepper motors tends to make a table act like a sounding board...
Now I can go back to controlling the printer from my PC in realtime when I want to, instead of having to stick files on the micro SD card. Although I eventually want to set up a Raspberry Pi WiFi webserver for the printer that can watch it through a webcam so I can at least kill a print from my phone if it starts going wrong from wherever I am.
I also need to print off a bunch of clips and edges so I can make a plexiglass box for the printer so I can keep it clean, and keep the air inside at a stable warm temperature so larger prints in ABS don't warp on me.
The leveling feet.
Checking for level and adjusting.
Printer set up, and checking it's print bed for level. On the money..