3D Printing background

Quick background on 3D Printing

There are different limitations for each method and each material, so you need to design for the method and material. Common methods:

Fused Deposition Modeling
Molten plastic extruded in thin layers. Most common hobbyist method.
Bath of UV-curable resin; lasers cure one layer at a time on the surface. Can be high-resolution.
Selective Laser Sintering
High-powered laser selectively fuses thin layers of powdered material. Can do metals.
Photopolymers sprayed in thin layers and then cured with UV
Binder jetting
Deposit binder liquid to join powdered material. Can do ceramics.

Design notes

In no particular order . . .

  • Build strength: FDM prints can be weak parallel to build plate (due to layers not fusing well)
  • In general, avoid more than 45 degrees overhang without support; more than that you can get drooping.
  • Minimum thickness of walls and features depends heavily on material and method
  • Tolerance when exporting to STL: 0.01mm. Anything more and the file may be too big due to excessive detail that can’t be used by the printer
  • Aim for a “watertight” mesh as in this diagram.
  • If sintering and you have open space, don’t forget drain holes.