Comment BS.. (Score 0) 302
With the different types of printer systems (FDM,SLA, etc.) you have different results. All are dependent on how well the calibration is of a printer. I have seen FDM printers (The hot plastic type) that are very accurate and print very nice parts. I have 2 of these machines myself. Many of the parts I make don't have to be "flawless" but are able to make life easier. Making brackets, tools, parts for prototypes, etc. Depending on what material you are printing with depends on how "Fragile" or "Bumpy" It sounds to me like any you have seen were crap machines and crap machines print crap parts. If you know what your machine is capable of, and what choices to make in the part design, as well as the settings for the print, you can make a product that looks like it was mass produced at a factory. And if you need metal parts, print a part in a water soluble filament like Hips and then sand cast it. Pour the molten metal in and then enjoy your part manufacturing capabilities. .
The SLA printers (the ones that use photo resin) are extremely accurate and create high quality parts. Maybe not as strong as FDM systems, but still very accurate and used in many industries.
They do have small build areas, but any home use or diy system will usually have that anyway. Even if it is a device like a CNC plasma table, Laser cutter, CNC Mill or Lathe.