Simple sphere joints calibration tool

Simple calibration tool with 6 sphere joints, great for testing before modeling joints in the 3D program so you have the exact movement you want after print. Very easy to print with only 8g of materials and 20min print time. Each sphere join has different diameter.The number on sphere is actually free space between sphere and wall. (example: first join has number 0.05mm, which means 13mm hole and 12.9mm sphere)