Working with support structures in 3D printing
Part of my challenge when designing the glasses for the Build Your Vision project is correctly orienting my design for print, to minimize the supports needed and thus the post-processing (including sanding and clipping) to create a smooth frame.
Our Series 1 Pro Printer uses Cura Type A -the desktop slicing software that prepares a model for printing. Models saved in the standard STL (StereoLithography) format are ‘sliced’ into thin layers as the 3D object is printed.
For the basic prototyping of the frame, I have defaulted to printing the frames standing upright, with supports set to ‘everywhere’, and platform adhesion set to ‘brim’ — a single, flat area that is easy to cut off. This type of support has resulted in the quickest print, with the most success, and minimal print failures.
The disadvantages are when the supports are taken off, there are a number of rough edges that need to be smoothed out during post-processing. However, the overall result is a mostly smooth, wearable piece.
I tried printing the frames standing upright with no support, and only a raft platform adhesion to anchor the frame to the print bed (when I printed with no support or platform adhesion, the frame moved around, and the print failed completely). The print did finish, but the surface finish was uneven, with some artifacts left on the front of the frame.
Furthermore, due to the hinge design -with the hinge connector overhanging at a 90° angle, I would need to either work a support into the design (which I would like to avoid), or use a program like Meshmixer to create custom supports for that section.
Printing with the face-side of the glasses down, with the connector pieces facing the print bed gives minimal rough surfaces on the front of the glasses, however the print time is much longer -about 1 hr, 50 minutes, versus about 1 hr for printing in the above orientations. Printing in this manner also leaves a number of support structures to be trimmed off and smoothed down. While printing in this orientation may not be ideal when we are printing in volume for the summer camp, when it is time to have Alta Vista students try out glasses designs one-at-a-time, this may be a viable option.
In the image above, I was also testing printing the temple pieces with supports and in different orientations. however, this is unnecessary — they can be printed without supports or bed adhesion for a smooth, clean output.
Finally, printing the frames with the face side of the glasses pointing up, resulted in too many artifacts and an articulated surface on the side of the frames closest to the wearers face, which is not ideal either.
Now I have more print testing to conduct, to come up with the ideal orientation and print settings for the best glasses print.
