I was watching this impressive video and the question came to me. Royal Marines Jet Suit Boarding Ex - YouTube
You mean 3D print the handheld jet thrusters? If so, I doubt it very much. I suspect the materials used are pretty special.
Integza is 3D printing rockets and other stuff you usually think cannot be printed. His channel is quite interesting.
Not a functional jetpack, but he shows interesting concepts and does a funny presentation with a nice science background. So learning by laughing! 
Toy rockets & such are 1 thing. 3D printing devices upon which someone’s life mignt depend are entirely another.
I would not consider his attempts as toys. I would rather consider his experiments highly dangerous.
I say toys in the sense that they are not for real, production use. They are interesting for sure. They’re also good proofs of concept. But, as I almost said in my last post, I wouldn’t put my life on the line by trying 1 of them.
I was just trying to imagine myself doing my shopping in Montreal during Covid lockdown with one of those gadgets. It does look like fun but must be kinda noisy.
You would also have to be immensely strong in that you have to be able to support yourself on only your arms for the entire flight.
That would surely let me out. They need one for grandfathers.
So printing a drone scaled way down would be impossible with the materials at hand. Hypothetically would it be doable if the material did exist?
I was just wondering what you do when you go hurtling through the air and the thrusters inconveniently conk out?
When I was watching that video I was thinking of the Somalian pirates and how that could cut their pirate careers short.
Drones can be 3D printed. There are plenty on Thingiverse, & there are websites dedicated to it. However, I believe the guy from Sweden who 3D prints lithos & T-shirts did videos about printing drones & found many of the materials, such as PLA, are not strong enough.
I’m talking about a jet pack drone with a little robot. Of course I know you can print drones. Trying to control a jet pack remotely would be quite challenging.