Axial Flux Windmill bearing hub

[Staffan]

Hi, I am building a Piggot-style wind turbine. Does anyone now, if I can use the hub of an old Ford Ranger? Any Experiences with Toyota? Thanks

[Texas Al]

You can use a hub from anything that rotates!

When it comes time to bolt it to the bracket, just cut a hole in the bracket big enough to accomodate the bulge at the end of the hub. I'm about to start the welding stage of the project myself, and looking at all the steel parts has made me realize that this part is very forgiving-- as long as you end up with a piece of metal that you can bolt your hub to, you're golden.

[Frank06]

I was just going to pose a similar question (8' Piggott machine) re a trailer hub.  The axle is rated at 1750# which seems pretty substantial to me but I don't totally understand all the forces on one of these machines yet.

The other question I had was regarding the type of hub that allows bearings to revolve in oil rather than using grease: anyone have any comments on this style?  It seems to offer less friction but I don't know if it's worth it or not.

TIA

[Ungrounded Lightning Rod]

When you consider that cars and trailers have hubs designed to carry a ton or more while hitting potholes in roads at freeway speed and taking pretty severe side forces on turns - applied more than a foot from the hub thus producing serious torque - you can see that they're typically overkill for a back-lot mill.

Even thought the mill gets most of its load as essentially centered side-force from wind and sudden twists from gyroscopic reaction to furling, rather than just the up-and-down from blade weight, the forces are pretty steady and mild compared to, say, hitting a curb or pothole on a turn.

Now if you want to build a mill the size of the ones at, say, Altamont Pass, you might need bearings a tad more substantial.  B-)

[ghurd]

You asked!   I know we had numerous Toyotas (Camrys, Corollas, and 2-WD trucks) go past 150k miles without the bearings being greased or tightened.  A friend had a lightly used Ranger where the bearings fell out of the cage under 100k miles, and they were changed in our Tempo at 100K miles.  Our Camrys had the same use as his truck. Our trucks are abused, like 20mph through snow covered corn fields, water level well past the hubs (half way to the windows), holes in the oil pan, stray bullet holes, broken in 2 shocks, broken front springs, bent rims, a bent front brake disk... And thats just the last 2 trucks.  Maybe some shop, sometime, greased or tightened some of them when we didn't know, but I doubt it.  They don't do that around here for free.

G-

[deloiter]

I built a modified Piggott design 8 foot gen using the hub from an old jetski trailer a little over a year ago.  Fairly light and easy to work with, yet still able to handle anything an 8 foot prop will throw at it.  My hub spindles were welded to a U-channel axle.  U-clamps were used to attach to the trailer frame.  I cut the U-Channel at the end of the spindle which left a nice flat surface for mounting.  Cleaned it up and used a good quality grease.  It should outlast me.  

[willib]

we also covered this topic  a while back..

have a look..

http://www.fieldlines.com/story/2006/1/8/144559/1140

[Frank06]

Thanks for the comments, I figured they'd do the job...  

Has anyone ever used oil instead of grease?  How important is friction towards good startup?  I wouldn't think that there'd be that much difference.

[Staffan]

OK, thanks for all replies. I will have a try to get a hub on monday. Because I am in Nicaragua Its not so easy to find European or American cars, someone told me, that most cars are from Asia and they have a  tendency to weld their hubs to the axle. I will see...

[Don Cackleberrycreations]

I have some axles from trailor houses  they are 3500 lb or better load rating

(the bearings are the same used in 1 ton trucks)

would these be stout enough for a 14-17ft mill or possibly larger?

[Experimental]

Yes Frank,

   Oil has been used, but you will find it very difficult to keep in the hub -- really good seals, cause drag and you will not know when that oil dissapears up there -- not untill the thing quits turning !!

    Grease is better (my opinion) just be sure to use an "all weather grease", meaning, it won,t freeze up at low temps --- I use aviation grease in mine, as it isen,t affected  much, by extreme temps and I use seals, because I live in a very WET location !!   At one time, Dan B, used no seals at all, but not sure he is still doing that !!??

   Hope this helps you, Bill H.....

[Frank06]

Thanks for your comment Bill - guess I'll go with grease.  The simpler the better, I guess.  Good point about oil disappearing and not being able to check it!