Designing for 3D printing

A few considerations are required for a successful print:

Materials:   We can currently produce prints in 3 different plastics: ABS, PLA, and PETE.  More materials are being tested but are not quite ready for production.

Of the current materials ABS is best suited for parts seeing actual usage (jigs, tooling, etc.); most people are familiar with ABS's use as the material Lego bricks are made from.

PLA is not as familiar a material, it is a bio-plastic derived from various plant materials, chiefly corn. It has an ultimate strength similar to ABS but is a more brittle material and cannot withstand the kind of heat ABS can.  PLA is best suited for mockups, models, and large prints (due to its low shrinkage rate).  PLA is also well suited for investment casting molds with its lower melting point and low fume emissions on burn out.  PLA is also an environmentally friendly choice as it can be composted in a commercial composting facility.

PETE is the material from which pop bottles and various other food containers are made.  Very flexible compared to ABS and PLA.

Design limitations:  The minimum feature width our printers can produce is 0.4mm (0.01575in), which is the diameter of the nozzle on the print head. 

The maximum size part we can produce is 246mm x 152mm x 150mm (9.685in x 5.984in x 5.906in) LxWxH.

Overhangs should be avoided where support material will be difficult or impossible to remove.  Overhangs will require support for any angle less than 45 degrees above horizontal.  The image below depicts the minimum angle that does not require support. 


Maximum_Overhang.jpg

 

Holes in the vertical plane will not come out perfectly round without support. Even when support material is used a hole in a vertical face will have a flat spot due to the layering of the plastic.  If esthetics are more important than function then you might consider making the hole elliptical to insure a good print (see image above).

Layer thicknesses can range from 0.100mm to 0.350mm, keep in mind the thinner the layer the more time it will take to produce your part, we’ve found that 0.250mm is a happy medium that offers good surface finish with decent print times. 

While parts with thicknesses of less than 1mm aren't impossible, they will require some specific design requirements. In general part thickness should be no less than the greater of 4 times the layer thickness or 1mm to ensure a good print.  Thin walled parts will also incur a price premium due to the general difficulties in obtaining a good print.  Please contact us for more information on designing thin walls for 3D printing.

 

Objects created by Fused Deposition Modeling are not food safe! 

Plasticwright reserves the right to refuse manufacture of items it deems unsafe.