Electric Flight in Australia


How do I assemble a folding propeller?

Peter Pine
1/40 Kellehers Road
Pottsville Beach, NSW 2489
Phone (02) 6676 1437
Mobile (0407) 732 440
E-mail: ppine@northnet.com.au  
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First, dress the blades removing any rough parts. Check the blades are the same size and shape. Thin the leading edge, trailing edge, and even the blade itself. Assemble the blades in the centrepiece with the bolts or pins supplied. If using bolts tighten them until the blades are stiff to move in the centrepiece. This will help to hold the blades straight while balancing the prop. Now it is essential that you balance the prop before use. To achieve balance sand the face of the heavier blade. To undertake this balancing act I recommend the Great Planes prop balancer, which is a threaded metal shaft with points, both ends. Two cones are screwed up on to the prop to hold it in the middle while you pivot the whole unit between thumb and finger to test balance. Once balanced slacken the bolts so the blades just swing freely. It is essential that you balance all props intended for electric flight use - there should be no vibration with electrics.

One further note - always make sure your folding prop has the blades swivelled backwards towards the aircraft when you are about to start the motor. The blades will swing forward and magically find the straight position. However, if one blade (or both) are swivelled forward when started it (they) may not come backwards to a straight position and will invariably cause damaging vibration.