3D printing movable parts can be a challenge. For this test, I chose a Planetary Gear Bearing from Thingiverse. Except for Tolerance (which was my test variable), I used the following OpenSCAD settings:
  • Outer Diameter of Ring: 63.5 (2.5 inches).
  • Thickness: 12.7 (0.5 inches).
  • Number of Planets: 7.
  • Number of Teeth on Planets: 7.
  • Number of Teeth on Sun: 14.
  • Width of Hexagonal Hole: 6.35 (0.25 inches).
  • All other values (except Tolerance): default.
I used PLA for all prints. I used the recommended Cura settings with Faster print times (0.2 Layer Height on Ultimaker 3 Extended and 0.3 Layer Height on Nautilus). I used 30% Infill on both printers. Support and Build Plate Adhesion were both turned off.

On the Nautilus, a Tolerance of 0.15 gave the best results. It took some effort to free up the gears, but once I did, the gears fit snugly and move nicely. A Tolerance of 0.20 resulted in a print that was easier to free up. The gears do not fit quite as snugly, but move nicely. With a Tolerance of 0.25, the gears moved freely right off the printer, but they are rather loose. This is really about the minimum acceptable quality.

Even with a significantly greater Tolerance of 0.30, the gears from the Ultimaker are still tightly bound up. I didn't test Tolerances of 0.35 and 0.40 on the Ultimaker. At a Tolerance of 0.45, the gears move freely right off the printer.

Clearly, for this test, the precision of the Nautilus far surpasses that of the Ultimaker.
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John Kray
Wow, great idea for a test! Glad to hear we can compete with the ultimaker. Thanks for the feedback.
Founder/CEO of Hydra Research LLC, developers of the Nautilus 3D printer and providers of 3D printing services.
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