1.5 inch Ram Mount Ball on a 10 mm bolt. Designed to screw into the corner post on a John Deere tractor.

I recommend a high infill percentage so the ball doesn't collapse when clamped onto.

This is designed so that the bottom half is printed, then a 40 mm long M10 x 1.5 bolt is dropped into the center, and then the rest of the ball is finished.

The tolerances around the bolt may not be perfect to allow the bolt to drop in without disturbing the print. It works on my printer but your printer may be different.

Slicing Tips:

1. The model will need to be elevated above the print bed approximately 20 mm to allow for the bolt to stick through the bottom.
2. This model must be printed with supports only touching the print bed.
3. But in order to allow room for the bolt you must block supports for the area directly under the bolt hole. In Cura, I used 4 support blocking cubes located at (0.5x0.5x40),(0.5x-0.5x40),(-0.5x-0.5x40), and (-0.5x0.5x40) to make room for the bolt.
4. Finally you will need to add a command to pause the print just before it covers the bolt cavity, this will allow you to add the bolt before the print finishes.