9mm Acrylic is a great material for tableware, cutting templates, signage, or any project that calls for the stiffest and thickest material in the Ponoko catalog.
While thicker acrylic is great for large simple shapes, there are some things to consider before designing interlocking or intricate shapes.
Since the laser beam is shaped like a cone, the laser cuts at a slight taper of 1-2 degrees.
The tapering causes the top side to be slightly smaller than the bottom side.
Just how great the difference between the top and the bottom of the cut is will depend on the thickness of the material - the thicker the material the greater the difference.
For 3mm acrylic, the difference is usually not noticeable. With 9mm acrylic you'll start to see a greater difference between the "entrance hole" and the "exit hole"
This means for designs with small holes, you'll need to account for the top hole to be slightly smaller than the bottom hole:
For designs where a perfectly cylindrical hole is needed, we recommend using two sheets of thinner material layered together, or use the lasers to create a smaller "starter hole" that you can clean up later using a drill.
When using laser-cut parts such as wheels or gears, you might need to position the parts in an alternating pattern so that the tapers “cancel out”.
If you have any questions about how to design for 9mm Acrylic, just shoot an email to service [at] ponoko [dot] com.