It´s not trivial to get a perfect result with “perfect” overhangs. It depends on the material, the printer you are using and on your printing settings, which angles of overhangs are possible to print. Typically, around 45-degree angle are possible to print. In FDM / FFF 3D printing, each layer must be built upon another. Obviously, you cannot print into the air and that´s why you must consider about some points before you start your print. Perfect placement, adding support structure or breaking the part into more pieces are common tricks to optimize your 3D print. You may use an overhang test model, like the one from the make magazine, download link: http://www.thingiverse.com/thing:533472/#files
Add a support structure
An easy way to get better results are support structures.
We can´t recommend which settings are the best, because they change when you change layer height or material. We recommend starting with the standard settings in your slicer program, if you have to change them > try > possible not good enough > try again: repeat the try and error method.
Keep in mind, that support material takes additional printing time and sometimes optimization of your models’ placement is another solution. Optimal support settings:
Reduce Layer height
To prevent your print of failed overhangs or to reduce support structure, it is also possible to reduce the layer height in your slicer software.
Part cooling fan
To realize higher angles of overhangs, your material has to cool down quite fast after printing it. If your printer has a part cooling fan you should activate it or increase the fan speed. Also check if the fan and ventilation slot are in right position (control, that the air cools your part and doesn´t go anywhere).
Some materials have an extreme low viscosity at printing temperatures and that’s why you must print them with high printing speeds and part cooling fan.
Adjust the print speed
As often it is a combination between printing speed and extruder temperature settings to get the best results for overhangs. We cannot give you the all-round solution, because it differs from material to material, from printer and part cooling fan. We recommend doing overhang printing tests to optimize your settings and to find out which angles of overhangs are possible. You may use an overhang test model, like the one from the make magazine, download
Some additional tips: We recommend a slightly higher printing speed when printing overhangs.
Adjust Nozzle temperature
As often it is a combination between printing speed and nozzle temperature settings to get the best results for overhangs. We cannot give you a general solution, because different materials, printers and part cooling fans influences the outcome of the overhang very much.
We recommend printing overhang tests to optimize your settings and to find out which angles of overhangs are possible.