3D Printing Tech Tips: Bridging Techniques Eliminate Support
Here at 3D Platform we take pride in our open-market solutions. Our 3D Printing Tech Tips series focuses on best practices for processing procedures from our very own technicians, making sure you get the perfect print every time.
Save Yourself a Headache
3D printing a steep overhang or surface in mid-air needs a support structure, right? WRONG! Using a technique known as bridging, you can save yourself the headache of breaking support away inside of tight structures and save material and time!
Bridging is a technique in which both speed and cooling of the material must be optimized. If the print is moving too quickly, the filament will break. If the filament is not cooling quickly enough, the filament will sag or “pillow” and the bridging technique will not work.
The gap in the image above spans 18 mm. I did not want to waste several hours by printing an entire part that would eventually fail without testing my bridging speed and cooling first. I used the technique of cutting the STL model in Meshmixer.
Taking the cut portion of the STL, I sliced the part in Simplify3D. My original settings had the bridging speed multiplier percentage set automatically at 140 percent.
Decreasing Print Speed
As soon as the bridging began on the print I knew the speed was too high. The filament strands were breaking almost immediately. I turned the LCD controller counter-clockwise to reduce the feed percentage. I continued reducing the speed until it was at 10 percent of the original speed.
100 mm/s @ 140% = 140 mm/s 140 mm/s @ 10% = 14 mm/s
I reduced the bridging speed multiplier percentage to 20 percent and ran the test again.
The result was exactly what I had hoped would occur. The bridging speed was dialed in and no support material was needed to print the unsupported area.
NOTE: Keep in mind that the larger the space to bridge, the more precise the speed and cooling will need to be dialed in and the more time and top layers the print will need to correct itself.
With 10 top solid layers, the print had more than enough layers to recover. I stopped the test prints and began the full model.
For other helpful hints, check out our blog.