Ball hone size

[bama]

I wanted to double check my figuring on hone size. The cylinder is 2 1/8 inches diameter. So my hone should be 10% smaller which comes out to about 1 7/8 inches. Right?

 

[TimberPig]

10% larger, not smaller.

2.125" *1.1 = 2.3375" or approximately 2 3/8" a 2.25" hone would work fine as well.