Every Sensenich propeller basic model (Ex. 74DM) comes off the CNC machine with the same median pitch. Depending on the specific aircraft, the pitch can be raised or lowered by 8 inches. This is done by placing a twisting bar on the blade around the 40% station and "twisting" the blade by moving the two hydraulic jacks attached (only one is attached in the picture) to the blade fixture.
Station lines are drawn on the thrust face of the propeller at set percentage distances from the center of the hub (Ex--45%, 60%, etc.). The pitch is then read with a protractor at each of these stations. The angles must be within 0.10 of a degree tolerance! Due to the unusual nature of most Sensenich airfoils (our thrust face is not flat), special templates must be used to hold the protractor level on the blade surface. Be sure when you are having a Sensenich propeller repitched at your favorite propeller shop that they are using these special templates!Return to Tour Main Menu.
Next Step--Removing More Material--Polishing & Buffing.
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