Building a wooden propeller

[Guest]

Hi

I am wondering if anyone has a paper or info regarding the process of building of a wooden propller(for a prototype). I have a paper from pedal power afloat but it is very vague. Would be grateful for any help!! Thanks

Boating enthuiast

[yipster]

no paper or info, but flashed back to childhood remembering a wooden airplane prop on the wall above the piano at my uncle's place. wooden airplane props may be easyer to find and perhaps informative in constructing a maritime wooden prop?

[Guest]

Hi again,

The paper i'm working on is http://mission.base.com/pedal-power/pp_prop1.html. This paper describes how to build a wooden propeller. I am stuck on page 3. If anyone has tried this before have they got any help? Or if anyone wants to try it out. I am doing the propeller in a 3D drawing package.

Thanks again

[yipster]

ah, where did that paper go? here the link you meant:
http://mission.base.com/pedal-power/pp_prop1.html
and a interesting paper it is! and why does page 1 not open on your adres? underscore perhaps?
now what was the qeustion...

[Guest]

oops. Sorry bout that but i just copied and pasted the address. I'm stuck at the top of page three. I'm very new to all this sort of stuff and the paper is a bit vague. i'm just looking for a more detailed explanation of his instructions as if to teach a child.

Thanks again

[jonathan]

Hello guest,

I just had a look at that paper and I think you have everything you need if you managed to go until page 3. I'm just going to paraphrase what they say, ok ? I've used a similar method to build model airplane props, and it works quite well.
Anyway, once you have the pattern cut out, just draw it as many times as you need on a sheet of plywood, but be sure to carefully mark the center. Cut them out and drill a hole in the center of each. once you have them, you need to build a strong support to assemble all the parts. They recommend a square of plywood on a frame, I don't think the shape really matters as long as it's big enough and flat. One thing you have to do is manage to put a vertical piece of wood (dowel) in the center, so that you can just drop all your pieces on it, and have them perfectly aligned. This means the dowel has to be the exact same diameter as the holes you did in the prop parts (3/4").

I hope this gets you going. If you need more help for the rest (alignement of the parts, gluing, etc) don't hesitate to ask.

[Guest]

Hi,

Thanks for the help but i'm afraid i'm still stuck. I'm not physically doing this as i'm drawing it in a 3D drawing package. I dont know how or where to align the laminations i.e what angles tohey should be at when attaching them. I'm not sure what he means in Figure 5 at the bottom of page 3.

Thanks for your time

[jonathan]

Well basically the angle between one laminate and the other wil determinate the pitch of the prop and also the thickness of the profile. so if you put the laminates more "on top of each other" you will have a high pitch propeller with thick section and low blade area ratio (the ratio of blade area to area of the circle it covers). The opposite happens if you spread them out too much.
Fig 5 is just showing you the shape each blade should have once they are sanded, smoothed, etc...
I don't think you have to worry about that just know, also I don't really see why you are drawing your prop that way, but... why not.

Good luck

[Guest]

Thanks Jonathon. I am drawing the prop this way as i have to build a prototype on a Sintering Laser Machine for a college project. To this i need a 3D solid image of it in a drawing package to import into the SLS machine computer. My prototype is not going to be made from wood at all, i'm using Duraform. And its not a manual process hence my difficulty in transferring the idea into the drawing package. I'm using this paper as a guideline on how to build a propeller using my own prop parameters. If you have managed to read the rest of the paper could you give me any hints or tips, bearing in mind that i'm using the drawing package to construct it instead of manually constructing it. I'm really new to the subject of propellers, especially designing and constructing them.

Thanks for all your time and tips. It has been very useful!!!
Appreciative student

[SailDesign]

Guest,
This may help ;-)

[Guest]

Hey
Nice drawings and very useful. Could i ask what package you used and what method?
Thanks

[SailDesign]

Guest,
That was Rhino. What "method?" You lost me there.
Maybe I forgot the disclaimner that the prop was dredged out of my memory of having to draw props by hand and is not based on any particular series.
It was offered more as a sample of a more efficient way to draw props in 3D, not a way to finish your homework earlier... ;-)
(I know, assumptions can be dangerous)
Steve

[John Moore]

Hello all,
Just to backtrack a little into this paper. I find page two of the paper confusing which is illustrated using figure 3: Lamination sizing. Any help?

John