Another take on holders for squash balls to make feet for Creality CR-10.
This has additional feet for the Y axis 40x20 extrusion to dampen harmonic vibrations from Y axis movements.
Requires M5 x 8mm screws + m5 t-slot nuts (min 2 per foot)
Update Dec 2018
As requested, files included for raquetballs that are 57mm diameter.
set wall/top/bottom thickness to >1.5mm so that only the extension block on the Y axis feet prints with infill.