Buzzing Casters

[Kendall Ross Bean]

David~

I had this problem too, but it wasn't just on replated casters. Frequently
the original grease would simply dry out and allow the balls to rattle. 

The first time I encountered it I was baffled as to where the noise might be
coming from. Usually grand legs don't rattle like that! It took me a couple
of days, on and off, to finally figure out where the rattle was coming from!

The difficulty, of course, as you discovered, is repacking the bearings with
grease when the caster is already assembled (in the factory I believe it was
much easier to pack the grease in before the balls and races were
assembled).

My solution was injection. Get a tube of lithium grease and squeeze the
grease in through any opening you can access (usually there is a gap where
the balls are visible. For those not averse to "aerosols", lithium grease is
also available in a pressurized can with an applicator tube to get into
tight spots - this method is very quick (-It's not technically an aerosol,
the lithium grease just shoots out the end of the applicator tube in
squiggles like toothpaste!) If you have a grease gun, you may be able to get
that to work as well, but usually the standard grease gun tip is too big,
and too awkward.

Before installing new grease, however, it's really necessary to get any
hardened little pebbles/cakes of old dried grease out of the caster bearing
(they are also in there rattling around with the ball bearings), or they
will interfere with the ball bearings' free movement. Some aerosol or liquid
degreaser, or soaking the caster in a jar of solvent overnight (unless it's
rubber wheel casters, of course) should dissolve the old hardened grease.
It's a good idea to get that old stuff out, because it's often not
compatible with the new grease you are putting in. Who knows what kind of
grease they used back then.

If you are just trying to quiet the balls, though, and aren't too concerned
about the casters swivelling on their bearings (they usually don't work very
well anyway!) just shoot the grease in and turn the caster a few times to
spread the grease around. They'll stop rattling.

Ultimately, like with so many other piano parts, they probably really
weren't intended to be repacked or reconditioned, just replaced! But I've
also noticed on the new ones, they also often come with inadequate
lubrication, and also need packing, (or you will soon have the same
problem!)

Hope this helps~

Ken Bean

PianoFinders

-----Original Message-----
From: David Love [mailto:davidlovepianos at comcast.net] 
Sent: Tuesday, October 28, 2008 8:33 AM
To: 'Pianotech List'
Subject: Buzzing Casters

I notice this problem frequently on casters that are replated rather than
replaced.  It seems that the plating process tends to remove the grease that
surrounds the bearings and they become free to vibrate.  Has anyone found a
reliable method for repacking or reinserting grease into the bearing area to
quiet those rattling little balls?

David Love
davidlovepianos at comcast.net
www.davidlovepianos.com