Have you tried these 12 steps for exporting your model for 3D Printing?

  1. Produce the correct CAD geometry
  2. All 3D CAD must be solid, i.e. closed 3D object geometry. All surface edges must be joined to another surface edge. The only surface geometry in your CAD files must be those that make up the solids. Turn any surface into a solid by giving it a thickness.
  3. Remember keep wall thicknesses at a minimum of 2mm. Even though 3D printers can handle printing down to 1mm thick, keep it at 2mm to avoid breakages during post-processing.
  4. Areas with thickness greater than 20mm should be hollowed to 5mm thickness. Above 20mm becomes to heavy for the printer.
  5. When hollowing a part, create a hole in one of the faces to allow the powder which will be left inside to be removed.
  6. Make sure you don’t have any duplicate objects in your file. You can delete these in CAD or Rhino by simply selecting your geometry and using the command : ‘OVERKILL’ - this will delete any duplicate or overlapping geometry.
  7. Do a ‘Save As’ copy of your file and turn the model geometry into MESH. You won’t be able to edit once the mesh is created.
  8. Watch out for very heavy file sizes here - the smoother the geometry, the more triangulated the surface, so the heavier the file! Lot’s of printers accept a maximum file size so make sure you control this by limiting the poly count when generating the mesh surface. Different 3D modelling softwares have different commands for generating a mesh or in Rhino - a NURBS object.
  9. At this stage remember to check for holes! Any gaps in the model will cause an error when 3D printing. Depending on your 3D modelling software, you’ll want to run an analysis of your geometry to check for gaps, select the defect surfaces and rebuild. Rhino is quite good for this, if you do the following: checknewobjects > selbad > rebuildedges. You can also analyse and fix ‘naked edges’ of your mesh by: showedges > fillhole
  10. From CAD model export to .STL format or .OBJ for coloured models. You can project RBG colour onto your model but that’s a whole other topic!
  11. If you’re working in Rhino, the best export settings are to set your CPlane to view to ‘World Top’ by right clicking on the Top View title ‘Set CPlane > World Top’. Move your object to the origin on the CPlane. Export same as CAD. STL settings under simple controls: with mm units use 0.001mm. With meter units use 0.0005m. Detailed guidelines can be found if you go to the Help menu > Help topics > index > mesh > detailed controls for export.
  12. You’re now ready to send your file to 3D print!