Axial measurement method of large propeller blade thickness
Because the propeller is a spatial curve in the blade, the caliper cannot be accurately positioned on the extension plane of the cylindrical section of the blade during the measurement. The point S is perpendicular to the direction of the pitch line of the pressure surface. The measurement accuracy itself is not high. There are also errors when comparing steel rule readings. Therefore, this thickness measurement method is greatly affected by the experience and feel of the surveyor. It can basically meet the requirements of the II and III precision blade thickness measurement, but cannot meet the S and I levels. Accurate blade thickness design and manufacturing, especially S and blades, in order to avoid linear discontinuities, stipulate that the deviation from the continuous measurement of local pitch and thickness should not be greater than half of the range covered by the positive and negative tolerances. Caliper measurement The accuracy simply cannot meet the requirements.
