Archive of the former Yahoo!Groups mailing list: Mellotronists

 

Ken Leonard wrote:

 

Although rare, it's not unusual to have to replace bearings.

MRC 104KSZZ
NSK 6004VVC3

The Prof showed me the trick of sticking your ear at the other end of
a metal bar or dowel that's against the bearing block and then
turning the capstan by hand.  Crunchy sound = bad---replace thebearings.

I've thrown oil at mine from time to time.  I don't know how much
actually gets in there---I need to get me one of those needle oiling
things for the next time.
 

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Greetings KL and everyone,  If bearings make a regular sounding
"clackety-clack" whilst rotating, similar to cadence of train wheels,
chances are the bearings are OK, but a bit dry. Esp. true on theolder
models (MK-II,SFX/M300) .  But grinding/cruching, nada ! Gottarepl. 'em .

Some "sealed" bearings aren't as sealed as others. Therefore, the
round felt washers adjacent to  pillow blocks, to catch anymigrating
lubricant.  In those instances, a precision needle-oiler (fromRat-Shack),
will do the trick. Apply a small drop on what appears to be innerrace cover,
NOT the capstan.

The metal rod trick is decades-old way that  car mechanics usedto
listen for faulty bearings or such in car engines. Kinda low-tech
stethoscope.  Buy hey, seems to work !
 

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Regarding motor oiling...At the Philly Symposium
(http://www.kleonard.com/mellotron/philly0501/working.htm)we went
over this and observed a few motors being cleaned/oiled.  In addition
to cleaning out the brushes, I do recall having to put a few dropsof
oil at either end of the shaft where it runs through the motor. I've
done this on #805 when I had the motor out and on "Mark" the Mark V
(http://www.kleonard.com/mellotron/mpb050604/index.htm). However I'm
not sure how effective this is.  I guess the idea is that someof the
oil works its way in there, and that's that.  Again, having oneof
those needly oilers might be a good idea.

Oh, I used Hammond oil.  I figure if it's good enough for one ofthose...:-)

I'm sure the Prof or one of the other tech guys can give us some more
detail (or un-do the lies I'm spreading :-) ) if needed.

...kl...  M400 #805 - old motor      ,   M400 #1037 - new motor

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The orig. motors have lubed bushings which get dirty/dry from age
and/or neglect. Once cleaned, armatures should be moving freely.
Needle-oiler as Ken indicated is very useful.

Sewing-machine or 3-in-1 (has nice smell too!) are excellent too.

I've endurance tested every motor here at the M-Ranch after
Prev. Maint. by running top-speed a minimum of 24 hrs. Checking
for drift in SMS electronics, etc.   See photo of oneexample.

....How does that old saying go ?......" A squeaky wheel ...... ?"

Cheers, -- JK--  (a bit squeaky, due to spring cold)