[GreenKeys] Lubricating Ball Bearing Motors

[Richard Knoppow]

----- Original Message ----- 
From: "Jim Haynes" <jhhaynes at earthlink.net>
To: "Bill Lewis" <bill at wrljet.com>
Cc: <greenkeys at mailman.qth.net>
Sent: Thursday, March 15, 2012 1:00 PM
Subject: Re: [GreenKeys] Lubricating Ball Bearing Motors


> Also, sometimes we replace motor bearings.  That's pretty 
> easy, as they
> are a more or less standard size that bearing stores 
> carry.  But sometimes
> the replacement that is available is a sealed bearing 
> rather than an
> open bearing, which means it can't be greased.  So I guess 
> when replacing
> motor bearings, if the replacements are sealed, one should 
> write a note
> on the motor to that effect so that nobody tries to pump 
> grease into it.
>
> Some years back my then-housemate and I replaced a lot of 
> bearings in
> Model 28 motors, trying to get the noise level down.
>

     It has been years since I dealt with ball bearings but 
at the time there were definite differences in quality.  I 
was rebuilding professional recording equipment.  The 
flutter was directly dependent on the quality of the 
bearings. I had a device that could measure rather small 
amounts of flutter.  At the time the best bearings available 
were made by Georg Mueller in Germany.  I don't know if 
these are still made or if the quality is the same. 
Different brands of bearings _felt_ different when turning 
them despite all supposedly being of the best grade.  I 
don't know if this was due to the lubricants used or to the 
finish of the bearings themselves.  I suspect the same 
qualities that resulted in the least speed variations would 
result in the least noise.  The difference in a tape 
recorder when switching from SKF or New Departure (the 
worst) to Mueller bearings was quite audible in the 
recordings as well as being measurable.  The recordings made 
with good bearings had a clarity the others didn't.
     These were all sealed bearings which is one reason I 
think the quality of the lubricant was important.


--
Richard Knoppow
Los Angeles
WB6KBL
dickburk at ix.netcom.com