2 DOF Flexure (2022)
Final attempt with thicker beams. No buckling in z
2nd real attempt with working kerf fits. We realized beams buckled in z
First attempt, 3 dof (3 rotations), about 10 degrees of motion
Motivation:
This is a homework from a flexure design class.
Description:
The flexure is supposed to rotate in 2 directions. This was a group project with 2 other students. I was responsible mainly for assembly and first order modeling calculations. The flexure has roughly 5 degrees of motion in each direction and is made from acrylic. I kerf fit all of the parts together, but we decided to glue critical flexure joints as a safety. We ended up making it 4 times. The first time (white), we got the motion incorrect but created that model just to get an intuition for how acrylic flexures bend. The second model (blue) worked, so we made a third model (pink) with kerf fits. We then realized that the stage translated in a 3rd direction due to buckling of two of the flexures. We then fixed this and created the 4th model.
Lessons Learned:
Do not add in decorative cuts on a laser because it’s a huge waste of time. Boundary conditions are incredibly important to stiffness and motion. Kerf fitting is hard, especially on a laser that is not tuned. Hard stops are important for flexure design. Remember to check buckling in beams. Super glue comes off of your fingers (but not fingernails) with lotion if it isn’t fully set yet.
1st real attempt. It buckled in z, but we didn’t realize