Although this is posted in completely the wrong category, I shall try to assist you.
Ceiling fans need to have balanced blades if they are not to wobble. At it's simplest this means that all blades should weigh the same, and they should all be exactly the same shape. But it's not quite as simple as that, as the brackets that each blade is secured to also have to be balanced.
In practice, good quality fans will have the blades carefully balanced by the factory, and on better quality models the blades will be matched to individual mounting brackets in which case there will be markings to identify which bracket goes with which blade (and also to identify where each bracket mounts to the motor).
Cheap fans (almost anything under £130) will not be carefully balanced and so whether they wobble or not is a matter of pot-luck.
To try and cure your fault, first remove and accurately weigh each blade complete with the brackets attached. You can buy strips of self-adhesive balancing lead to add a gram at a time to the upper side of the tip of any blade which is under weight. Note that if any blades are damaged, you must repair the damage before weighing. If any blades are twisted along their length (normally they're simple flat paddles set at identical pitch angles by the way the brackets are shaped) then they must be counter-twisted to match the other blades. Also, check for manufacturer markings to see whether there are any suggestions as to which blade goes with which bracket and whether the brackets are marked to match a particular mounting point on the motor (usually simply by matching coloured paint blobs).
Once you have checked all that you can, see if the wobble remains. If it does you should try swapping the brackets around on the motor: by doing so you'll normally remove the wobble altogether or will considerably reduce it. You might not achieve perfect balance, but you may get to a point where the resonances which cause the wobble offset each other.
A well-balanced fan will not wobble appreciably at any speed, a less well-balanced example might still wobble at some speeds and not others.
I hope that I've helped and that you will take a moment to rate my answer. If there's any part of my reply which is unclear to you then add a comment and I shall try to assist you further when I'm next online.
Answers & Comments
Although this is posted in completely the wrong category, I shall try to assist you.
Ceiling fans need to have balanced blades if they are not to wobble. At it's simplest this means that all blades should weigh the same, and they should all be exactly the same shape. But it's not quite as simple as that, as the brackets that each blade is secured to also have to be balanced.
In practice, good quality fans will have the blades carefully balanced by the factory, and on better quality models the blades will be matched to individual mounting brackets in which case there will be markings to identify which bracket goes with which blade (and also to identify where each bracket mounts to the motor).
Cheap fans (almost anything under £130) will not be carefully balanced and so whether they wobble or not is a matter of pot-luck.
To try and cure your fault, first remove and accurately weigh each blade complete with the brackets attached. You can buy strips of self-adhesive balancing lead to add a gram at a time to the upper side of the tip of any blade which is under weight. Note that if any blades are damaged, you must repair the damage before weighing. If any blades are twisted along their length (normally they're simple flat paddles set at identical pitch angles by the way the brackets are shaped) then they must be counter-twisted to match the other blades. Also, check for manufacturer markings to see whether there are any suggestions as to which blade goes with which bracket and whether the brackets are marked to match a particular mounting point on the motor (usually simply by matching coloured paint blobs).
Once you have checked all that you can, see if the wobble remains. If it does you should try swapping the brackets around on the motor: by doing so you'll normally remove the wobble altogether or will considerably reduce it. You might not achieve perfect balance, but you may get to a point where the resonances which cause the wobble offset each other.
A well-balanced fan will not wobble appreciably at any speed, a less well-balanced example might still wobble at some speeds and not others.
I hope that I've helped and that you will take a moment to rate my answer. If there's any part of my reply which is unclear to you then add a comment and I shall try to assist you further when I'm next online.