Balanced foot for tripods

This is a sketch of a rounded tripod feet to be used on hard surfaces, such as tiles, do not recommended for outdoors use, specially over irregular or soft floors as it will introduce more instability.

Foot adapter sizes are estimated and do not correpond to an actual tripod model.

Edit1: added actual size for my SkyWatcher tripod.

Edit2: this a failed design. The lower part needs to be bigger. I increased it 5% and it was still too weak, it breaks when the ball of the upper part is in