PVC Pipe prop plans and History

[wooferhound]

 I have been moving my better projects into my diary. But while I did draw up the plans for the PVC Pipe Props, Zubbly was

the one that pretty much invented them. This is why they are called ZubWoofer Props. So instead of reposting the Prop plans

in my diary, I decided to post the history and evolution of these props. Some fo the pictures in the earlier posts don't

show up because Zubbly was also learning how to post pictures at this time too.

Zubbly invents the PVC props and first mentions that he is making Props from Pipe

http://www.fieldlines.com/story/2003/9/7/16254/83196

Some of Zubbly's first descriptions of the Props he is making

http://www.fieldlines.com/story/2003/10/5/185824/882

The first good pictures of the PVC Props and discussion of durability

http://www.fieldlines.com/story/2003/10/19/171250/17

Plans are starting to emerge and Wooferhound is posting Drawings Too

http://www.fieldlines.com/story/2003/10/25/020/94523

Wooferhound starts making Props and makes a 4 Blade version

http://www.fieldlines.com/story/2003/10/29/17144/245

After talking on IRC chat Wooferhound decides to Draw Plans for the props

http://www.fieldlines.com/story/2003/11/11/172721/53

Wooferhound makes PVC Savinous experiment

http://www.fieldlines.com/story/2003/12/1/122243/608

And that is why they are called ZubWoofers

It's really cool for me because I am seeing pictures of them from all over the world

Recently 'stevesteve' a user in the UK wrote a computer program that greatly simplifys the measurements needed to cut one of

these blades out of the pipe. You can download the program from this story

http://www.fieldlines.com/story/2005/4/17/6437/83378

Happy first time cheap prop building from Wooferhound

[electrondady1]

thanks nice and dense information

[gizmo]

I've been using PVC for my smaller windmills, but on a 3 blade propeller.



How will that calculator program work with 3 blades? I used Warlocks calculator to get the angles and it seams to work ok, but "stevesteve"'s would be a lot easier to use.

Glenn

www.thebackshed.com

[stevesteve]

Glenn,

Should be OK for you. The calculator just works out the width of the paper template for required angles for a particular pipe diameter (angles and diameter set to your requirements).

I'm intending to do something similar myself. I am trying to locate some larger diameter pipe in the UK. I can only get 4" so far.

Cheers, Steve

[MtnTopRebel]

Humm might be a solution for me... I have an old gear drive Pre REA windmill, that needs blads.  The unit is designed for two blades but I might have to modify it to 4 and shorter blades....  guess I will need to dig it out get a pix and seek some advice...

[nanotech]

Find a construction company.  They should have up to 10 inch diameter pipes for commercial sewer lines.

Might have to sand the blades thinner, because at a 10 inch diameter, the pipe's going to be kinda thick.

Don't know whether shipping would kill you, but these guys have quite the selection.....

http://www.pipeplus.com

[Peppyy]

Hey, don't forget about these that charge my booster packs.

[Norm]

    Do you have details on this one?

  Diameter of pipe used ....diameter of swept area...rpm in 6-8mph wind?

    Looks good!

              ( :>) Norm.

[stevesteve]

They seem to be US based but I will check out some UK construction suppliers.

On the other hand a 3' or 4' section would do so I might cruise the local building sites touting for offcuts!

Cheers, Steve

[windyknight]

Whats merit in 4 blades vs 3 - cant seem to find info on pros and cons!

[Peppyy]

I have some information on them here

http://www.fieldlines.com/story/2005/1/6/232942/4004

They were made from 4" pipe and are 48" long.

Windyknight, the only reason I made this a 4 blade setup was for use of material VS. strength. It was a whole lot easier than building a fancy hub and bolting everything together.

I have no scientific data to support it but from what I have read here in the last couple months I would be willing to bet I would get better performance from 3 blades. It has to do with what I call "Prop wash". At higrer rpm's the air is still disturbed when one follows the other at 90 degrees apart. With 3 you have 120 degrees between them allowing a bit more time for the air to settle back into it's path, thereby creating more power.

Of course, the swept area would be smaller, limiting the power factor and the startup speed so the low rpm performance would be slightly less. I guess it is a bit of a tradeoff and without some real test figures it is all theory.

[windyknight]

Think there might be some torque benefits, I seem to recall most planes with 4 blade props were carriers rather than fighters but someone must have data! k

[jimjjnn]

WWII  F4U(?) Corsair had 4 blades and 13 foot swept area. That was the reason for the  gull wing shape of it's wings.

[Norm]

   A four-bladed prop on a plane was supposed

to be quieter than a 2 or 3 bladed one.

             ( :>) Norm.

[rotornuts]

"silent running" hellicopters such as the MD 500E utilized 5 blades instead of the standard 4 so they could reduce the rotors rpm and still generate the same lift. The reduced tip speeds yielded a noticably quieter rotor according to the manufacturer. "NOTAR" also dramaticly improved the noise levels.

[di34]

Hi Great information

Here is useful info Alise