Have you ever wondered how the Mini's prop blades sit when the motors are running?

[Deleted member 103366]

For some reason this thought popped into my head this morning. First thought was fully extended under 'centrifugal force', then I thought "but as the speed increases so does the 'drag' exerted on them". The centrifugal force, is if I remember correctly, proportional to the square of the angular speed but I have forgotten about drag etc.
A quick and very careful check with a pointer and the Mini at idle suggested they are fully extended at idle.
Out comes my camera, I really didn't expect to see the props but with the flash on 1/60 sec.

 

[scro]

Haha.. I've pondered the same thought, but not got to the point of taking a photo to check. It almost looks as if the motor casing is leading the blades slightly, which would be intuitively expected, due to drag. Perhaps try a photo looking straight down so you can see the relative angle between the motor casing and the blades?

 

[Deleted member 103366]

I will have a play, I was just surprised at 1/60th freezing the action and had it in my mind that I would have to set up a couple of flashes firing 'manually' at full power with the camera on manual.

 

[scro]

The actual flash duration is usually a good bit shorter than the shutter speed of 1/60th, so that the preset flash power all happens while the shutter is open. Assuming you're using a typical "Speedlite" or similar camera mounted flash the lower the flash power the shorter the actual duration of illumination: a 1/2 power flash is a truncated version of a full power flash. Setting your flash to full power will give you the longest duration of illumination and highest chance of blurring fast moving objects.

 

[Deleted member 103366]

Ahhhhh wunderbar, thank you.

 

[Deleted member 103366]

Two overheads 0953 at idle, 0954 at full throttle

 

[scro]

This appeals to the engineer in me ? Not much difference between them, and it kind of looks like a few degrees of lead on the motor compared to the blades. Less than I expected.

 

[Deleted member 103366]

I wasn't sure what to expect lol. I will at some point check the DAT file and see what the motor speeds were. I am surprised there was so little blurring.