Touching-Ball Tetrahedron for Tomography
Below we see a miniature tetrahedron (10 mm balls) . The 4 ruby balls are pressed together by spring force.
They form a very reproduceable tetrahedron array. No glue is used.The calibration is performed on the individual balls.
Only carbon fibre composite, plastic screws, tubes and ruby balls are used.
This is an excellent resolution test artefact as the balls‘ distance starts slowly growing from zero.