I was running my printer on a piece of carpet to isolate vibration. I've been looking for a more permanent solution and saw that some people have used tennis balls with attachment mounts. I wanted something smaller and found these foam rubber practice golf balls. They are made of medium density foam rubber with a tough exterior. They are only 41 mm in diameter which make them compact and low profile. I designed a mount that accepts a 1/4-20 or 7 mm hex head screw. The screw pushes in from the bottom and rests in a hexagon shaped pocket. The mount screws into the threaded end of my 2020 extrusion on my HyperCube printer. The balls are retained by four small barbs on the inside rim of the mount. They are pressed firmly in place but can be pried out if replacement is needed. The balls are cheap and readily available. Here's what I used:
Be sure to print with supports.
These mounts quiet vibration transmitted to the table and do not introduce any printing artifacts.
You must use supports
I printed in PLA but ABS or PETG would be good.