Accuracy for 3D Printed Plastics

Please use the following guidelines for tolerances and accuracy of 3D printed (additive manufactured) components. Note that this is based off of typical results.

  • SLS: +/- 0.005" or +/- 0.002" per inch, whichever is greater. Build area up to 13 x 13 x 20" (13" max dimension preferred)
  • FDM: +/- 0.004" or +/- 0.002" per inch, whichever is greater. Build area up to 24 x 36 x 36"
  • PolyJet (PJ3D): +/- 0.004", or +/- 0.001" per inch, whichever is greater. Build area up to 19 x 15 x 7"

Additional notes:

  • SLS (Selective Laser Sintering): Note that thicker geometries, large broad parts, and parts with uneven wall thicknesses may deviate due to thermal shrinkage and stress. This can look like warping or twisting. Even wall thicknesses and similar design guidelines as injection molded parts are encouraged. Very small gaps and holes may be tighter than designed, a 0.006" offset of small gaps and holes will help these features achieve closer to CAD results. SLS prints in 0.0047" (120 um) layers.
  • FDM (Fused Deposition Modeling): FDM works well for mechanical geometries, larger parts, and parts which may not require ultra-fine features. Very narrow pegs and lips may not resolve due to the bead thickness deposited. We recommend minimum feature size, including text features, to be at least 0.035" (0.045" is safest). FDM prints in 0.010" layers (254 um), 0.013" layers (330 um) on parts over 16" max dimension.
  • PJ3D (Polymer Jetting / PolyJet): PJ3D is a very fine detailed and accurate process. Although the material is not as robust as the FDM or SLS thermoplastics, the rigid and rubber-like photopolymers have the highest detail resolution for features like text, surface, and lip seals. PJ3D prints in 0.0012" layers (30 um). This process works best for final fit-checks before molding, highly detailed pieces, and parts that are used as sales models.
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