How can you print complex and intricate shapes with 3D printing?

In my experience, it is about what you want to design and who is working around you. The FDM printers absolutely can do fine detail. You can use smaller nozzles and you can slow down the prints. You also have options with different types of filament. Decent printers can be purchases for $200.00 and up but you must learn to tinker with them to print well. The SLA or resin printers have issues with fumes and can be quite messy. They are able to do intricate detail as well but for me the mess and the fumes are two things I cannot adapt to in my printing environment. Again, as with FDM, price will be a factor. Cheap SLA printers can be purchased but you will have to learn the ins and outs to troubleshoot.

Designing small features in 3D printing requires careful consideration to ensure accuracy and structural integrity. If features are too small, they can lead to fragile or unusable parts. Specialized software tools like MeshLab or Netfabb help address this issue by enabling the creation of optimized designs specifically tailored for 3D printing.

I agree with Matthew; the purpose in design should be to use the least amount of supports as possible. Can you change the direction/orientation of your design to not need supports? Can you change the settings on your machines, such as the speed of the print, to not need supports? Questions to ponder before printing. Also, there are usually settings in slicers to achieve the support needed to get the design to print.

Despite challenging designs, build orientation minimizes the number of supports required. A key mentality to printing is the part is being grown. Each technology will have different stability ranges which require more care. Supports expand those limits beyond those unstable areas during the growth process. Optimal support structures are material and application specific. Designing supports should be thought of as a minimization problem. "What are the least number of supports to allow drawing compliance?" The upfront work minimizes the back end post processing work.

Some additional considerations to take into account for your settings, in my experience, are choices related to what material you're working with. Whether SLA or FDM, different materials behave differently with different settings. PLA, for example, will need a print surface between 55 and 65 degrees to adhere to a PEI-covered sheet. On glass with tape you can even print cold. Having your print volume enclosed will also be necessary to avoid warping during the print process with ABS, Nylon or PolyPropylene. Another thing to consider is the ambient environment. A humid and warm room will need different settings than a cold and dry one. So if you have seasonal variations, your print settings need to adjust as well.