3DVision Technologies has two different 3D Printing technologies available, FDM (Fused Deposition Modeling) and PolyJet. Both technologies are similar in that we build or grow our parts from the bottom up layer by layer. Building our parts in layers does need some extra consideration (more than just simply hitting the print button). That layering technology means our printed components (right from the printer) are Non-Isotropic. This means the strengths of the material changes depending on the direction of testing. This is more evident within FDM.
When considering part orientation, most people instantly think of money, making it as cheap as they can as far as material usage goes. There is more at stake than money, what are you doing with this printed part? If you are physically testing your parts, the Non-Isotropic nature should come to mind, but what else should you be worried about?
Stratasys defines six part orientation considerations. They are Build Speed, Support Structures, Surface Quality, Strength, Support Removal, and Airflow. Over the next few weeks, I’ll be diving deeper into each of these. For Volume 1 I will focus on build speed, and surface quality.
Let us consider this L bracket:
When you need a part very fast, the biggest thing we can do when orienting our parts is minimize the Z height. The X & Y direction of the Gantry is much faster than Z. We must also keep in mind surface finish requirements and any post processing that might be needed. In this case, the fillet will be stepped because of the layering.
Surface quality is another big one. Coming from an engineering background, aesthetics were never my strong suit. We needed a machine to function, and function well. The way the machine looked was never at the top of my to do list (I can hear all those Industrial Designers screaming at me right now). Any curves cutting across the in the direction of my Z plane will end up with a Stair Stepping effect. See below. If the surface quality is important, rotate the model so the curves do not cut across the Z Plane. This means sacrificing that extra material and time to have a better looking part.
Still have questions? Ask them in the comments section below and stayed tuned! Next month we will be posting Volume 2 of this Guide.