Constant Velocity Joint for TestDrive

The 3D-printed universal joint worked well on the TestDrive. However, it wouldn't meet the shorter joint requirements for my new model.I'm considering using a 3mm-to-3mm metal universal joint (FC004) from Bambulab or a Constant Velocity Joint based on the Rzeppa design.I tested my simplified Rzeppa joint (using only 4x 3mm steel balls) on my TestDrive model and it worked quite well. It ran smoother than my universal joint.I wanted to share this here for TestDrive users who would like to