I find the 2" ball just about right for 45 size and up props, adds a nice gentle cup. Nylon capped hammer works great too.
This ones's gonna be 63mm with 6.75" of LE and 7.75" of TE pitch.
Lessee, mph x rpm / pi = pitch. No that ain't it. pitch / mph = rpm. Naw that ain't it either...
Terry this what I use in Km per hour ..
KPH/L.E pitch x 656 = rpm ( 200kph/4.5 x 656 =29155rpm) minimum rpm required for that speed.
RPM x L.E pitch/ 656 = speed ( max speed you will
Go at that certain rpm). 30000rpm x 4.5in /656=205.8Kph