PVC BLADE DIMENSIONS

[Yianie123.]

I was wondering if anyone has worked out and tested real PVC blades for for 3ft and 4ft blades?  Still working on my 8ft diameter winfturbine.

[gww]

Some had luck with pvc, I didn't and I did have luck with wood blades.
Just my experiance.
gww

[dnix71]

The blades on my AirX are some kind of plastic, are not the original, and they work well. They do have a metal hub.

[DanB]

I just gotta throw it out there that in my opinion this stuff about PVC blades has been going on for years and I wish people would forget about it.  In my opinion it maybe good for a brief science experiment.

[tanner0441]

Hi

I played with PVC blades, including reinforced and profiled.  Anything over 3ft diameter it is too flexible and when the hit the tower or break they shatter with very sharp splinters if they are at all cold.

They do however seem to spin up very quickly and have reasonable performance for low power low wind, but the moment there is any turbulence or high wind conditions keep away from them.

Brian.

[klsmurf]

Hi

I played with PVC blades, including reinforced and profiled.  Anything over 3ft diameter it is too flexible and when the hit the tower or break they shatter with very sharp splinters if they are at all cold.



Brian.

I agree with this completely.  I found it was just as easy to take a 2x6 and profile the back, as to get a workable profile on a piece of pipe.

I do have a 4ft. diameter set, made from 8in. sewer pipe.  They work well on a ametek 40.  At about 20 mph wind speed they flex back so much that they limit the speed.   No furling needed.    They will eventually break.

[Yianie123.]

The idea is to try the profile in PVC, then try the same profile on aluminum pipe. 

[tanner0441]

Hi

Forget aluminium pipe they will crack and break faster than PVC.  Aluminium work harden and crack if they bend too far they won't return aluminium has very little elasticity.  If they hit the tower and don't rip off they will buckle all shapes and if your not there to shut it off there is a chance something is going to shake itself to pieces.

I was very apprehensive about making wood blades and the first set I made were from a 5ft length of pine 4x2 and roughed it out on the table saw, then with an electric planer, and finally with a belt sander, balance and polish was done with a DA and orbital sander. it spun up easily and produce reasonable torque.  I then made 3 blades 18ins each put them on a hub and put the complete assembly in the electric drill. Impressive you could almost lean into it.


Brian.

[DanB]

wood is nice

[opo]

By the time you realize you are on the fourth or fifth replacement blades with PVC you could use all that time to build a set of "simple" (no twist) wooden blades with will outperform any PVC or other pipe based materials. There is a lot of lift developed by a basic profiled well balanced wooden blade.

Octavio

[phil b]

If you want to try the profile, consider using fiberglass pipe. It is more expensive but you would have more time to test the profile and it is safer. PVC is a poor choice for blades. Look at what the pros use.

[Yianie123.]

By the time you realize you are on the fourth or fifth replacement blades with PVC you could use all that time to build a set of "simple" (no twist) wooden blades with will outperform any PVC or other pipe based materials. There is a lot of lift developed by a basic profiled well balanced wooden blade.

Octavio

What are simple "NO TWIST" blades?

[gww]

I made a simple no twist set on a table saw, lots of utube vids for ones made with 2by4 lumber on table saws.  It worked better then pvc and was easier to work with, IE: mount. 

The twisted blades are the bomb.  I like them best.  I don't do good work and many times get big gouges and grooves on my blades but they still work well. 

My opinion is they don't have to be made very well to work really well.  I do like the ones I have done well better cause they just look good.  I am not sure they work much better then the ones with mistakes.

I will say that once the big chunk is out on the twisted blade, where the large drop is cut out,  I use a cheep harbor fraite hand plainer and a 20 dollar angle grinder with a 35 grit sandpaper disk.  I use a chain saw or saws all to cut the big chunk out. 

The table saw blades worked but the twisted are faster.  I hated the pvc blades.
Just my opinion. 
gww

[Yianie123.]

I made a simple no twist set on a table saw, lots of utube vids for ones made with 2by4 lumber on table saws.  It worked better then pvc and was easier to work with, IE: mount. 

The twisted blades are the bomb.  I like them best.  I don't do good work and many times get big gouges and grooves on my blades but they still work well. 

My opinion is they don't have to be made very well to work really well.  I do like the ones I have done well better cause they just look good.  I am not sure they work much better then the ones with mistakes.

I will say that once the big chunk is out on the twisted blade, where the large drop is cut out,  I use a cheep harbor fraite hand plainer and a 20 dollar angle grinder with a 35 grit sandpaper disk.  I use a chain saw or saws all to cut the big chunk out. 

The table saw blades worked but the twisted are faster.  I hated the pvc blades.
Just my opinion. 
gww

Can you please send me a site on making non-twisted windturbine blades?  Many thanks.

[hiker]

simple no twist blades--ceder planks with airfoil on backside--slight feathering  towards end of blades--plywood hub-with groves cut at the proper angle...

[gww]

I would start here and watch all three.

https://www.youtube.com/watch?v=uT2y5JJ24f4

I have made these and they can be cheep to play with, couple dollars a board.  If you listen close you can get the settings for a 10 degree slant instead of twenty degree. 

I believe you will end up with twisted blades but even these are better and easier then pvc. 

These are the absolute simplest to make, but even using them I would look at hughs plan and incoporate a plywood hub and three blade system. and anything else easy enough to incorperate.
gww

[Yianie123.]

Thank you all for hour comments......

[Yianie123.]

Thank you for all the information on no twist blades.  It seems that is it slightly easier, but still a problem if you do not have a table saw.   I'm still open to any other means of making blades if anyone has any.  Thank you also for having this site.

[MattM]

I'm holding out for the CNC cut blades on a 8' x 8' disk, jet turbine style. 

So far the price is still out of my range.

[Bruce S]

Yianie123;
Have a look at this thread about using a chainsaw too.
http://www.fieldlines.com/index.php/topic,140626.msg941414.html#msg941414

IF by chance you don't have a chainsaw, follow the idea anyway.
Do a little more searching on here and as I used to say "Google is your friend  "
People here used to carve their 'mill blades with noting more than a draw knife and board saw.

Cheers