DR1's own
McGyver Seriously, good job when one of those fans get out of balance in my unit I call for a repairman, just can't seem to get them balanced properly
Like harmonising a helicopter's blades,it's important that firstly they don't have a significant difference in weight (blobs of ceiling paint or bits broken off from throwing the baby too high etc.) and then to ensure that the blades are all exactly the same height,or distance from the ceiling.To the nearest half centimetre (or 55/332 or something,of those old fashioned inches for our American brethren).This can be done by bending the recalcitrant blade(s) gently up or down as required.Many fitters don't do this and finish up with a manic corkscrew trying to lethally destroy itself and nearby residents at speed.