concentric_circles

cults3d

This is a testing model for 3D printing. Our goal is to print two wheels, join them together seamlessly, and spin them smoothly, as shown in the video below: https://youtu.be/KiCR8q_Z9a8. There are three key factors to be evaluated in this test. Firstly, how well-defined your printed lines are (well-retracted and well-started). A circle should be precisely closed, without any bridging to adjacent circles. If the circles appear unclear due to inadequate retraction or restarting, it's impossible to join them seamlessly. Secondly, no back rush occurs. Back rush or vibration of the timing belt causes distortion on the circles. Even if you've successfully addressed the first point, distorted circles cannot be rotated smoothly. Thirdly, there is perfect symmetry between the X and Y axes. If your 3D printer lacks sufficient symmetry or a right angle in these axes, it leads to distortion on the circles. This issue can only be resolved by addressing the first two points. Note that this problem is irrelevant for Cartesian printers but may arise in Delta printers occasionally.