16x16 drone skid with steel ball (1/4 inch) whole

This is a remix of the 16x16 skid, removed a little material at the sides just because and also removed two of the screw things, this is so you only use two screws to fix the skids to the arm.

Added a 1/4 inc sphere whole so a steel ball can fit and do cool skids

After print just force the steel balls into the hole, they should go easy and won't come out, tested it.