I have one that I go through phases using. I have used it to do things like a car phone mount that has a wireless charger. A screen mount for the 5” display for my RPi. Perhaps the most useful was for a glovebox catch that kept breaking and Ford wanted a fortune for a replacement.

There are libraries full of projects online that are kind of fun. I fully admit my ownership is more for fun and to scratch a design itch than the printer being of real practical use.

My machine does leave noticeable ridges in the finished project and you have to be careful if it is going to be load bearing with the amount of infill you use (denser=more filament) and the direction of printing (not as strong when shear is parallel to print layers).

I have got far more use than I actually thought out of mine.

Admittedly a lot of that "use" was tweaking and modifying the printer itself, but even so I have printed out a huge number of models just for the fun of it, as well as learning some basic Fusion 360 skills and designing & printing some stands for synth gear and some computer case parts/mods along with other more practical stuff.

chevrolux:

The only real limit to what you print is how good you are with your 3d modeling software of choice. If you've got time to learn, you'll print anything you want.

Even if you have no skill or desire to learn, there is a vast number of existing designs available for free on Thingiverse and other sites, catering for all sorts of needs, both practical and frivolous!

I'm onto my 4th 3d printer. What I enjoy most is the design of new things. I've done quite a number of designs, ranging from a mount for my gate latch to an Elbonian Dilbert character, to cool mechanical devices to 3d-printer parts to a detailed aircraft rotary engine.

The worst thing about 3d printing is the frustration when it just won't print properly for no apparent reason. If you want to avoid that, I suggest you get an upmarket name-brand printer rather than something cheap from AliExpress. My advice is that any 3d printer will cost you at least $1000, either up-front, or in hours of work (at maybe $1/hour). The more you spend up front, the less hours.

Beware that designs published on Thingiverse and elsewhere are of variable quality (I guess it's probably the same on sites where people publish their own (Vogon) poetry). There's any amount of trivial stuff like aircraft with cylindrical bodies and rectangular wings. And heaps of stuff that is practically unprintable (e.g. aircraft which are a single object). And heaps of 3d printer parts & phone cases. My rule of thumb is to ignore anything where there isn't an actual photo of the thing that has been printed by somebody. Having said that, I do have large collections of cool, printable things that I plan to print "one day".

If you're into RC model aircraft, there's a blossoming of large-scale 3D-printed flyable models at the moment.

I questioned the value in getting one for work, but since we have, we use it a lot for:

• Custom enclosures
• DIN rail mounts for misc devices
• Custom brackets to mount various devices

Granted it will take quite some time to pay itself back on purely material costs (it wasn't a cheap one) it is saving us a lot of time in the workshop custom building stuff, and if we want more, we just hit print and let it rip.

Whether you "need" one at home would probably depend on what hobbies you have.  

I'm a mechatronics engineer by trade and I've found having a printer endlessly useful for home projects.

I've got a Prusa mk3. As others have said above, you either spend less upfront and spend hours tweaking it to get good prints, or spend more upfront and spend time printing. 

I mainly print functional parts designed myself - mounts, cases, brackets. Latest print was a solar panel mount on a pole for an IoT project. Not really into the miniature figures and models for display.

Other uses:

• Prototyping parts before cutting steel.
• Printed my partner a headset mount for her work desk and next day had requests from the rest of her team for one each.
• Father has requested many motorbike parts - cable clamps, clips etc. Printed in PETG they lasted him 40k+ kms, I printed spares for him which he never needed on his journeys.
• Toaster handle broke off by old age, copied in CAD. Microwave push to open button at friends. 

I think you need to be willing to learn CAD (if you don't already know it) and design your own parts to take full advantage of having a printer. If you have any hobbies that need parts then you will always find a use for one.

I recently was given a CubePro 3D Duo, and about 15 mixed filament cartridges.

Unfortunately, no longer supported by 3D systems, but that can be worked around.

It's bit of a behemoth!  And the second extruder has an overheat issue. prints for about 5 minutes, and then throws an error. Web site is not that helpful.

But have managed to print a couple of samples - they look not too bad.

Wife suggested making customised puzzles for the grandkids - a 4yo who is into dinosaurs, so could make one of those skeleton puzzles based on his name.

Have to trial out the 3D system Invent program that came with the printer. A few reviews advise that it's not too bad ..

6 printers and access to a 3D metal printer. But they are partly used for the job (having an idea, which needs to be visualised overnight for a prototype. This is why there are many units to print multiple parts in parallel).

I have an Ender 3 and a Malyan M200. Print in ABS and PLA. Mostly printer mods, small parts, recently made a nice speaker holder for my nest mini

Don't have one, but my local library does!  Always wanted to try it.  The lady there is super helpful, aparently its about 60c to make a reasonable sized keyring.  Resolution didn't seem to be awesome, but I'm keen to try it!

To work out some of the frustrations of the continuing Level 4 restrictions I have been doing some 3D design and printing. Mainly some modifications for my Galaxy Z Fold3 phone case (still waiting on the phone itself).

I have a XYZ Da Vinci 1.0A printer which is coming up 7 years old and is really starting to show its limitations, not the least of which is that the filament cartridges it uses appear to no longer be available. There are hacks out there for being able to reload the cartridges but really I'm thinking its time for an upgrade to a more modern machine.

So I'm looking for fellow GZers comments on a decent replacement. I want something that has a reasonable sized build area 300x300x300 ish and can use a variety of filament types. Can be open or enclosed as I'm happy to build an enclosure if necessary.

At the moment I have found Creality Ender and Flashforge models that are available locally as well as a rather more expensive 3in1 (printer/laser etcher/cnc mill) Snapmaker model. Does anyone have any experience with models in these ranges?

I have an Ender-3 Pro. What a rollercoaster! I love it. A great teacher of patience. The things I print are either really useful or just trinkets. Lots of upgrades and tinkering. Great hobby.

I have a cheap-as Ender clone. Use it to print all sorts of items that are handy but not in stores - for example mask clips that stop fogging of glasses, adapters to allow masks to be fixed around back of head rather than on ears for more comfort.

Last year made a lot of face shields using printed frames and OHP plastic. Generally give them away to those needing them in local stores that have to stay open.

I find Mattercontrol the best design software for bespoke solutions.

Recently I reproduced a plastic sliding hinge for our old firewood shed.  Was easier than purchasing another complete shed.

Make the odd parts for work that are no longer in production from OEM.  That has been more regular than anticipated