Correlating Michigan Wheel Cup Gages

A HydroComp Technical Report
Report 136

 

Overview

One available standard for propeller cupping can be found with the Michigan Wheel Cupping Gages. The table and plot below show the magnitude of the trailing edge "drop" (for use in NavCad and SwiftCraft) and correlation to the nomenclature in PropExpert.

Trailing edge "drop"

Gage #1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #11 #12
Drop [in] 0.015 0.030 0.045 0.060 0.075 0.090 0.105 0.120 0.135 0.150 0.165 0.180
 Drop [mm]  0.4 0.8 1.1 1.5 1.9 2.3 2.7 3.0 3.4 3.8 4.2 4.6

PropExpert cup definitions

PropExpert uses its own definition of cup in terms such as Light, Medium, Heavy. The following plot can be used to quickly determine the corresponding PropExpert definition for a given combination of propeller diameter and cup gage.