Design Guidelines

The following information outlines our design guidelines and limitations for the 3D printing services we offer. Any unique requirements and tolerances the parts need to meet must be presented at time of quotation via email.

Unless otherwise instructed, Forge Labs prints 3D models as they are provided to us. Typically, we are able to notify our clients of potential problem areas, but Forge Labs cannot be held responsible for failed prints, or models that break when being cleaned if they do not meet the standards laid out in the Forge Labs Design Guidelines.

PolyJet Matrix Technology:

Accuracy:

  • PolyJet accuracy is approximately ± 0.127 mm (± 0.005 in.), or ± 0.0015 mm/mm (± 0.002 in/in), whichever is greater. The larger the part is the looser the tolerance – if you need a specific tolerance on a part, please ask

Dimensions

  • Maximum build size is 490 x 389 x  200 mm (19.3 x 15.35 x 7.9 inches).
  • The layer resolution ranges from 16 to 28 microns, depending on the settings specified. Standard layer height is 28 microns unless otherwise stated.
  • Minimum recommended wall thickness is 1 mm (0.039 inches). Thicknesses that are achievable in the real world depend on the design of the part, and walls built to the minimum thickness may be fragile when cleaned and finished.
  • Embossed or debossed details should have a depth, height, and width of at least 0.5 mm (0.02 inches).
  • Extruded text should have a draft of 5 degrees, to minimize breakages during cleaning
  • Pins and holes have a minimum size of 1mm diameter (0.039 inches). Deep holes are harder to clean and may have support residue remaining after cleaning. Pins that are longer than they are wide are still fragile and may break during cleaning
  • Clearance for moving parts, hinges, joints, etc, is 0.3mm – 0.4mm on all sides.

Support:

  • PolyJet parts are printed with a support material that is mechanically removed with a high pressure water jet after printing.  Hollow sections will be automatically be filled with support material – large holes must be included in the 3D model to allow this is to be removed.

Surface finish:

  • There are two surface finishes available – glossy and matte.  By default, surfaces in contact with support material will print matte, whereas any surface facing upwards can print either matte or glossy.  Additional smoothing can be achieved through manual finishing.
  • VeroClear prints translucent, but it can be made optically clear by polishing after printing. The matte finish is recommended to prevent yellowing. Small features and detailed internal cavities that can’t be polished by hand may appear cloudy and translucent, rather than completely clear.
  • Other guidelines:
    • 3D models cannot have overlapping geometry, incorrectly oriented normals, or ‘holes’ in the surface – they must be water-tight.
Fused Deposition Modeling (FDM):

Accuracy:

  • FDM accuracy is approximately ± 0.127 mm (± 0.005 in.), or ± 0.0015 mm/mm (± 0.002 in/in), whichever is greater. The larger the part is the looser the tolerance – if you need a specific tolerance on a part, please ask

Dimensions:

  • Maximum build size is 914 x 609 x 914 mm (36 x 24 x 36 inches).
  • The layer resolution ranges from 125 – 330 microns, depending on the settings specified. Standard layer height is 254 microns (0.010″) unless otherwise stated.
  • Minimum wall thickness is 1 mm. Thicknesses that are achievable in the real world depend on the design of the part, and walls built to the minimum thickness may be fragile when cleaned and finished.
  • Extruded text must have a wall thickness of at least 1.5 mm (0.059 inches) when printed flat, and 2 mm (0.079 inches) when printed in the Z-axis.
  • Minimum resolvable feature size, including text, is at least 1mm, or greater.
  • Depending on orientation, circular holes can flatten out to ovals – if higher accuracy is required, printing the hole smaller and then drilling it out is recommended.
  • Pins should be at least 5 mm (0.197 inches) in diameter.
  • Clearance for moving parts, hinges, joints, etc, is 0.5mm on all sides.

Support:

  • Our Fortus FDM printers print using soluble support for most materials- meaning that support material can typically be washed off without leaving visible ‘marks’ from where it contacted the model.
  • Hollow walls and enclosures will be filled with support material, and must be designed with drain holes so that the support can be dissolved and removed during cleaning.
  • Parts can either be printed in ‘solid fill’ or ‘sparse fill’.  By default, all parts will be printed with solid fill unless otherwise specified.  ‘Sparse fill’ prints large volumes with a honeycomb structure instead of solid plastic to lower material costs.

Surface finish:

  • Note that FDM has visible layer lines, especially on curved surfaces.
  • 3D models cannot have overlapping geometry – they must be water-tight
Stereolithography (SLA):

Accuracy:

  • SLA accuracy is approximately ±0.025-0.05 mm per 25.4 mm (±0.001-0.002 inch per inch). Accuracy will vary, depending on build parameters, part geometry and size, part orientation and post-processing method.

Dimensions:

  • Maximum build size is 1498 x 762 x 558 mm (59 x 30 x 22 in)
  • The layer resolution ranges from 25 to 100 microns, depending on the settings specified.  Unless otherwise specified, we will print all SLA parts at (HD) 50 microns.
  • Minimum wall thickness should be at least 1 mm (0.039 inches) for unsupported walls, and 0.7 mm (0.024 inches) for supported walls.
  • Embossed details must be raised at least 0.1 mm (0.004 inches)
  • Debossed details should have a width, depth, and height of at least 0.4mm (0.0157 inches).
  • When designing parts that fit together, keep in mind that surfaces may grow by ±0.127 mm (0.005 inches).
  • Holes should be at least 0.5 mm in diameter (0.02 inches)
  • Clearance for moving parts, hinges, joints, etc, is 0.3mm on all sides.

Support:

  • Hollow sections will be automatically be filled with support material – a drain hole of at least 1 inch (25.4mm) in size must be included to avoid damage to the part as uncured resin expands. If it’s not possible to put a hole that large into the enclosure, multiple smaller holes must be placed (one to allow the material out, one to allow the air in).
Selective Laser Sintering (SLS)

Dimensions:

  • Maximum build size is 650 x 300 x 560 mm (25.6 x 11.8 x 22 inches)
  • SLS accuracy is approximately ±0.3%, with a lower limit of ±0.3 mm (0.012 inches)
  • (Minimum wall thickness is 1 mm (0.039 inches)
  • Embossed or debossed details should have a depth, width and height of at least 0.7 mm (0.028)
  • Holes should be at least 1.5 mm (0.059 inches) in diameter
  • Clearance for moving parts, hinges, joints, etc, is 0.5mm on all sides.

Support:

  • Hollow sections will be automatically be filled with support material – drain holes of at least 3.5 mm in size must be included to save material