Constant Speed Prop Dynamic Balance

[skippydiesel]

The DB instructions for my constant speed prop, advise that the DB be done, at Cruise RPM,  with the prop on the fine pitch stop.

 

Having  followed the instructions, I thought I may digress and see what happens when the prop is turned to a Crusie pitch setting.

 

The vibration increased marginally - still well within the recommended level. 

 

I have writen to the prop manufacturer, asking why the prop is not balanced at the Cruise prop setting, where I spend most of my flight time - early days, yet to have a reply.

 

I thought this might be a good topic for the Forum to discuss/nut out.

 

Any thoughts?

 

😈

[FlyBoy1960]

more cavitation ?

loosing the laminar flow because tha AOI is to high and your losing air in the boundary layer ?

[skippydiesel]

18 hours ago, FlyBoy1960 said:

more cavitation ?

loosing the laminar flow because tha AOI is to high and your losing air in the boundary layer ?

Please expand.

 

How might your theory impact on vibration analysis/correction/balance??😈

[FlyBoy1960]

you need to think about a propeller flying through the air, much like a wing on an aircraft.

 

If you increase the angle of attack on the blades by going to course pitch you are effectively doing what you would do by pulling the stick back and getting stall buffeting in an aircraft. That is probably whether vibration is coming from. It doesn't help that you are sitting on the ground just beating the air.