balancing a ceiling fan

[conneticat]

If you have alot of ceiling fans throughout your house, the best way to balance them all at once is to determine which fan blade is causing all the trouble with each fan, orient all those bad blades north, go to the south side of your house and jack the foundation up a centimeter or two with a couple of house jacks, available at your local home supply center. Be sure to restart all your fans simultaneously or you will have to start the process over again, using the west/east method. You may want to get a few packages of shims to relevel your countertops and keep your small appliances from sliding off.

[john]

get a piece of chalk and tie it to a sitck. Move the stick inward to touch the tip of the blades while the fan is running. The blade that gets the mark of the chalk is the heavy one. Put the weight on the opposite side at the tip... thumb tacks and washers put in the top of the blade are easy to install.

Helicopter blades were done the same way before they came out with Chadwick balancers.

John

SteveB wrote:

[larry]

After all the effort to get the weight exactly the same on all the blades and the fan is still out of balance. Do this simple test. Run the fan at low, medium, and high speed. Does the balance get worse with higher speed? I thought so ;-)

Now, fix the real problem. The pitch of each blade must be identical! The pitch is the angle of twist from the leading edge to the trailing edge of the blade. Most blades are mounted with an "H" shaped bracket and can be adjusted by slightly twisting the bracket at the short section between the two outside bars of the H.

You can use the reflection of a light bulb off the flat of the top or bottom of the mounted blades to adjust the twist so the bulb appears at exactly the same place on all the blades as you hand rotate them. I can almost tell you, only one of the blades will be off when you do the first reflection test. Tweak it back into position and your fan will run true at any speed.

I spent 4 hours moving quarters, nickels, and dimes, swapping brackets, blades (yes, weighing was the first thing I tried-they were identical) and it ran so well, until I switched to medium speed ;-) I spotted that the reflection of a nearby lamp on the blade surfaces "wobbled" as I turned the blades. It's the pitch! One blade was really "off". In a few minutes I had the same lamp reflection on all the blades. Fan then ran smooth and quiet at all speeds.

It is very easy for a blade to get hit and the bracket twisted.

-larry / dallas

[SteveB]

Well, IF the goddam thing was balanced, it wouldn't wander all over the room in the first place, would it?

Steve ;-)

[SteveB]

You know, great minds think alike. Last night, I lay watching the fan and pondering the same thing. I came up with paint on a brush, but I like the chalk idea. The heavy blade will always swing farther out.

I bet they lost a lot of people before the Chadwick balancers.

Steve

[SteveB]

"larry" wrote >

Those look like they're cast and won't take much tweaking before breaking. But I will investigate it with the light bulb thing. Sounds like a simple solution to a complex problem.

Kind of against my nature.

Steve

[David Merrill]

IF the fan is suspended on a rod, check for swinging of the rod resulting in a slight rotation of the rod suspension bearing and a bit of stiction (breakaway friction) in the dried out suspension bearing. If so, cure it with a bit of wax or white grease applied to the suspension bearing. Be sure the fan is turned off when you attempt to do this :-)

David Merrill

[Martin H. Eastburn]

First - swap to adjacent ones. Spin up and see if it is reasonable. Often the case. Installed a balanced set but two are swapped.

Installer won't take the time.

Martin

Mart> I don't know why, but there have been a rash of ceiling fans introduced into

[Trevor Jones]

Never heard of anyone getting hurt doing tracking of blades, but it's pretty unnerving!

If the tips are colored with different colors of chalk ( the helo's I knew of were done with grease pencil/china marker), and a ribbon or cloth is brought into contact, the colors will transfer and give you a "print" of the differences in the blade tip paths.

That only works to give you the track, though, and you still have to adjust both the track and the balance to get a smooth runner.

Cheers Trevor Jones

[MG]

I have a ceiling fan goes Groan Groan Groan. As soon as turn the power off the noise quits which is telling me that the problem has a strong electrical components rather than simply a mechanical problem.

Any idea on what to look for when I take it down and open it up.

Thanks

Mauro

[john]

I never did Helicopter blade balancing but did a lot of prop balancing. Its amazing what a couple of washers will do to get rid of vibration. An old time pilot showed me how to put a cup of coffee to good use. Put it on the floor of the cockpit and adjust the prop govs. till the vibration rings disappeared from the surface. That little trick sure stopped a lot of cowl cracks and other vibration oriented damage.

John

[clare at snyder.on.ca]

If you are afraid to twist, put washers under one screw to raise one edge. Put washers on the head end of the equivalent screw on all other blades to maintain ballance.

[Martin H. Eastburn]

[Bruce L. Bergman]

Damn skippy - you can spend an hour or two futzing with a fan that isn't tracking quite right, and still not get it perfect enough for some picky people. And when I install them the boss usually quotes a price that doesn't allow for that time.

I make sure the resident saves the balancing kit, and knows why. And I mention to do the tracking and attack angle checks before playing with the weights.

The fan may run fine when I'm done, but anyone can bend an arm at any time if they stuff a hard object into the path of a running fan.

-->--

[DerbyDad03]

-- Helicopter blades were done the same way before they came out with Chadwick balancers.

Where do I sign up for the job of marking a rotating helicoptor blade with a piece of chalk tied to a stick? Maybe I'll just look for the longest line, cuz that's got to be a d*mn popular job!

[Andy Asberry]

These are REAL fans. I have five that have been in three houses.

Don, how is the speed change effected. Is it simple resistance or cutting out some of the windings or ?

They never groan on high speed and usually only with a single globe schoolhouse light. Placing a large rubber band around the globe where the retaining screws contact will help some.

--Andy Asberry--

------Texas-----

[Trevor Jones]

You mark -non-rotating- blades ends.

The pilot sarts the rotors turning, stabilizes them at flat pitch, then a tech or mechanic slowly feeds a special pole with a cloth band on it, into contact with the tips of the blades.

Have you ever seen those little combination toothpick/dentalfloss units? Shaped sorta like a letter F, with floss between the tips of the horizontal bars. Same principle, larger scale. The position of the base is pre-marked out. Place the butt of the pole on the mark, pivot in until contact is felt, then out again. Walk clear, read the marks, while the pilot shuts down, then adjust as required.

Repeat as many times as you have to.

Cheers Trevor Jones

[conneticat]

Helipcopters, if properly balanced and hung upsidedown, make a fine whole-house fan when installed in your attic. Check with your local helicopter recycler for the recommended copter for your square footage...Blackhawk for a 2600 square foot home, small news chopper for a home under 1200 square feet. Be sure to post a warning on your attic door telling tall visitors to duck.

[SteveB]

wrote

And warn your mother in law with the big hair.

Steve

[M Q]

I had one like that. I thought that the motor was a goner. It turns out the the hub was a little loose on the shaft and had slipped down a little to where it was scrapping on something. I raised the hub slightly and tightened it and removed a handful of metal scrapings. It now runs great.