how would you model this blade ?

[Rakela Raul]

can you please direct me on how to model this blade??
it has a thin area, a fat area and the tricky thing is the 'twisting' of the one end.
thanku in advance

[Dwight]

two meshes - one deflected up and over, one deflected down and around

[Rakela Raul]

Thanku Dwight, I will give it a try rt now....i was expecting to get some sleep tonite, but I guess that can wait till tomorrow nite !! thanku again ..
i have noticed several times that i underestimate the mesh tool..., i didnt even think of it !!

[Dwight]

The firm got shortlisted for three public art projects today otherwise I would model an example for you.

Trick: make your top mesh, then duplicate it and drop the central nodes for the bottom- this way the edges stay together.

[Anonymous]

Hello Raul,
Never underestimate the the mesh tool.
For controlled organic shapes in Archicad
it is often the only tool that can do it.
I was looking at your image and I don't
see the "twist" in the blade itself.
To me it appears that the pitch is controlled
by rotating the entire blade about it's long axis
at the hub unlike a normal propeller blade which
is twisted within the body of the blade.
Peter Devlin

[Dwight]

But I have an Otter prop here and the actual prop blade is quite flat - shaped like a wing with a tricky transitional twist at the base - unlike laminated wooden props from before WW2.

In Canada we had an airline pioneer named Max Ward who crashed his plane up North and built a prop. It is easier than it looks to build one - a saw, a drawknife and a spin balance.

At the Boeing museum in Seattle there's a shop drawing on cutting a block of wood to carve a prop. very pretty. Tried to use it to model a prop myself but too hard....

[Anonymous]

Hello Dwight,
Which type of propeller blade do you think
most resembles the blade shown in Raul's image ?
You would agree that this relevant to how to model
this object. If it has a twist in the body of the blade
then you would have to change the plane that you
use as the X,Y plane of the mesh.
Peter Devlin

[Dwight]

I'd make the blade like a wing and bulge the shoulder down into the pitch adjustment coupling.

Here's a set of profiles to consider:

http://www.greeleynet.com/~cmorrison/airfoil3.pdf

[Anonymous]

Thank you Dwight,
Now both Raul and I have the the section fairing lines
to make this kind of blade.
As usual, you have taught me something. This time about propeller blades.
Now I wonder if you know something about submarine propellers.
They are different from normal surface boat and ship propellers
Thanks,
Peter Devlin

[Dwight]

Of course they are different, designed to work underwater like that.

haha.

But I CAN tell you about sewage impellers.