TheBackShed.com

Home	JAQForum Ver 24.01
Log In or Join
Active Topics
Local Time 02:16 15 Jul 2025	Privacy Policy
Jump to

Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.

Forum Index : Windmills : On-site_blade balance check

Author

Message

Gill

Senior Member

Joined: 11/11/2006
Location: Australia
Posts: 669

Posted: 10:07am 14 Jun 2008

Copy link to clipboard

Print this post

Here is a method for checking blade balance of an existing windmill when on-site and the resources needed for the more accurate method presented by this site are not available.

Firstly, check blade position, orientation, and tracking.
Choose a no draught time or location and remove the rotor to eliminate cogging,

Then check the static balance:
Position one blade at the 3o'clock position. Hang a small weight, (say like a fencing wire hook with a small nut as weight) over the blade close to the hub. Unless the weight is too heavy, it will not move. Gradually move the weight along the blade, until the blade just starts to move. Mark this position on the blade. Repeat for the other two blades. If the positions are all the same, then the hub is in balance. If one blade mark is further out than the others, then this blade is lighter. You need to adjust the balance by adding weight to it. Repeat this operation until all blades have the mark at the same distance out from the hub.

This method has some merit in that it uses the point where the frictional drag of ball rollers, grease and seals are overcome by the slide weight. Whilst consistency of this drag threshold cannot be assured, it is far better than just seeing which blade hangs lowest. Edited by Gill 2008-06-15

was working fine... til the smoke got out.
Cheers Gill _Cairns, FNQ

Gill

Senior Member

Joined: 11/11/2006
Location: Australia
Posts: 669

Posted: 02:33am 15 Jun 2008

Copy link to clipboard

Print this post

Further to the above,
I feel this method could be well used to static balance VAWTs. The string method of balancing is not suitable. This may be the best method where the physical structure can not have a top and/or bottom shaft protruding. Unfortunately static balancing of most VAWTs is more easily done with the axis horizontal. I don't see a way around this.

Well that's just some ideas I thought worth a comment.

was working fine... til the smoke got out.
Cheers Gill _Cairns, FNQ

Print this page

To reply to this topic, you need to log in.