Can one make a 3d printer with a larger 3d printer?

No. The things can only make plastic right now.
Not to mention all the electronics that would require a far greater printing resolution than any current and near future 3d printers could even dream to achieve.

It’s not like a Star Trek replicator at all. What 3D “printers” do, in a nutshell, is simply layer plastic on top of plastic to form items, as opposed to the typical process of injecting plastic into a mold.

@Darth_Algar All we need is layers of beef with marbling, and we have steak.

Possibly, but it will only look like a 3D printer on the outside.

@talljasperman

Perhaps, but rather than trying to rig a 3D printer to “print” beef, grind the beef up to be fed to the printer, figuring out how to get the printer to actually print and form it into a steak, it would probably be easier and cheaper to just go to the butcher and buy a good cut of steak.

“The RepRap project is a British initiative to develop a 3D printer that can print most of its own components.” – Wikipedia

@ragingloli not entirely true, they have printed a few organs using some cellular paste, hooray for science!

If I got my hands on one, I’d print a bunch of my own wargaming miniatures. But as others have said, it’s nothing quite like the star trek replicator. Most of them can only use a plastic or resin “ink” to create objects. To print another 3d printer, you would need so much more (like copper for wiring, what ever the hell circuit boards are made up of, magnets, etc.) at best you can make most of the plastic parts of a 3d printer, or a miniature model of a 3d printer.

As @jaytkay points out, a RepRap can make about 90–95% of the parts to make another RepRap. However, it cannot do the control circuitry, stepper motors, or the actual print head (which is a bit like a glue gun).

What you want is sci-fi style nanites that not only don’t exist yet, but probably never will so long as we have any restrictions on WMDs; the potential to weaponize them is a threat that makes nuclear weapons seem trivial.

A couple of techs at work made one from parts printed on another printer. They then used the one they made to print those same parts again. It obviously was only the plastic bits.

Odds are that I could make more with one than most people here could.

At the very least, it requires a bit of skill with CAD software to even make a model of the finished product, plus a bit of computer skill to turn that CAD model into code that the printer will accept. While there is free, open-source software to do both of those, the software isn’t exactly user-friendly enough to read your mind and make a flawless CAD model and program; you’ll need at least some computer skills. Maybe in the future that will no longer be true, but that will be after we have volitional AI. See here for a bit more info.

There is also the engineering end of it. You cannot always print the finished product directly. That is especially true if there are “undercuts”. You will have to be mindful of the geometry of the desired part(s).

As for what one can make with a 3D printer, how about a car? Yes, despite all the hoopla frop the MPAA about piracy, even Porsche wants people to download a car. And I know that 3D-printed parts are used to make molds used in foundries to make certain castings as well. Or maybe prosthetic hands. Many things are possible!