Dimensional Accuracy

Our tolerances for SLA models and rigid PolyJet models are +/- .005 inch total for dimensions less than 5''. For dimensions larger than 5'', we hold +/- .0015 inch per inch.  For example, if you had 2 screw bosses in your file that were 10'' apart, we could produce a solid model that held this feature to within +/- .015''.   We can hold the same tolerances for most of our cast urethanes, however there are a few materials that are tougher to control dimensionally and thus have a slightly larger tolerance.  Be sure to ask your Sales Manager or Project Manager for more clarification about dimensional tolerances with your cast urethane project.

For Laser Sintering, in the X and Y axis expect your parts to be +/- .005'' from nominal for all features smaller than 2", and +/-.003" per inch for all features larger than 2".  In the Z axis, expect your parts to be within .010'' of nominal in the first inch, and +/- .003''/inch, for each inch thereafter.  For larger quantity orders where multiple runs are involved, we can make adjustments to subsequent runs based on the dimensional feedback of prior runs, to improve dimensional accuracy over time.

Critical dimensions: When a feature of your file is CTF (critical to function), please let your project manager know before we begin working on your project.  In many cases, we're able to work with you on critical features, and can ''err on the plus side,'' or ''err or the minus side,'' or 'keep that feature material-safe,' however you specify.  Rapid prototyping is all about proving your design, so help us help you get you the best proof possible.

Optimizing your files
Better accuracy on features can be achieved by refining your .stl file output settings.  Please see the .stl file page for tips on how to make good .stl files. 

Selecting appropriate prototype materials
Material selection also contributes to dimensional accuracy.  Some SLA resins are more accurate than others, also some urethanes are more accurate than others. Our expert staff can assist in selecting the appropriate resin for your SLA's, and the best Shore A or Shore D materials for your cast part applications. For more information about our materials themselves, click here: Materials Specifications Sheet

If you have any questions, a special request or want additional information, please contact us.