I work with various industrial benchtop or pilot plant used equipment. I've had my son print many plastic parts to repair broken equipment. You always get stuff cheap at auctions when it's (perceived) broken. They work fine now.

I'll be using one in college.

I do 3D printing and am a member of a group on Facebook. It amazes me that so many Americans (much more than other nationalities) are obsessed with wanting to use 3D printing to make guns.
You can do so much more with a 3D printer.

There is no hope.

The only 3d printing technologies that are affordable for an end user are plastic or resin printers.

So if you want plastic tools or a plastic gun, go crazy. It's far easier to just go buy a gun, honestly, and much cheaper too.

A 3d printed plastic gun that fires a single bullet just isn't that effective compared to an actual gun. If you buy a 130,000 dollar printer that can print metal objects, well, the economics are just stupid. I am absolutly certain I could get a lot of guns for 130,000 dollars almost any place in the world.

I can use my lathe and milling machine to make guns too, and that's not regulated. I could cast my own brass cannon as well... None of it makes any sense logically.

A zip gun can be made from hardware store parts as well.

-- that is the current reality---

Someday 10-20 years from now, it might be a problem, but there really is no way to put that cat back in the bag.

There are some signifigant changes on the horizon and they aren't going to be easy for society to deal with as a whole. (or at least predictably for now)

AI, Desktop Manufacturing, Automation, are all approaching very fast and are not going to be easy to regulate, if even possible. That doesn't even touch what we are heading for with DNA editing and protein modelling.

-- this stuff is coming and there is no god to help us get thru it. --

Yes I it can and has been used to print gun parts. I can print projectiles but you would still have to get the powder and primer separate and those are very hard to make and tricky to purchase.

@azzow2

Yes, you can print tools on them, and you can use it for business. 3D printers are basically personal factories, but it's good to make sure to make things that won't break.

For example, don't make in-house ornaments out of steel, because those things won't need to take a beating.

Don't make tools out of cheap plastic, unless you know how to make the components link together to become very strong.

For example, let's say you want to make a handle for a hammer out of cheap plastic, for whatever reason. It's better to print the biggest number of small pieces possible, while using the same amount of material, and then glue those pieces together, versus using a single piece.

Here are some 3d model downloads [turbosquid.com]