I'm presently in the process of rebuilding an Ampico A.  This system
was pretty well restored about 25 years ago.  The most obvious problem,
at least to the owner, was that the replaced tubing was breaking.
Indeed, I found all the small tubing brittle.  The pneumatics had been
well recovered in black Nylon.  I am checking each one as I get to them.

The bellows were not restored, so I had the morbid fun of digging 26
rotten tacks out of each bellows, as well as the reservoir.  As I put
26 new tacks back as I was gluing things down, some poor re-builder is
going to have the same job I had.

I am now in the process of replacing all the bearings.  The re-builder
had just stuffed as much oil and grease into the old ones.  I drove
them out and cleaned them.  They felt gritty, rough and even bound at
spots.  I am finding this problem more and more often.  In fact, I have
changed my attitude: I now assume that bearings will have to be replaced.
Fortunately, bearings have been standardized, at least here in the US,
and replacements are available.  I have several contacts here in
Seattle and I would guess there are more available on the internet.

The original numbers on the side of the large bearings are ND 1203 L,
on the small bearings ND 1200 L.  I have replaced them with S 203 FF
and 6200 NSE C3, respectively.  New bearings make all the difference
in the world.

If your system has background noise -- a hum or moan that is noticeable
especially in rewind -- chances are it's the bearings at fault, not
motor hum.  An easy check to verify is this: Unhook the big drive belt
and turn on the system.  The only thing moving will be the motor.  Is
there hum?  Then it's the motor.  If not, then it's in the bellows,
i.e., the bearings.

Duo-Art systems are difficult because they have bearings in the arms that
are very difficult to remove and new ones may not fit easily.  The last
one I did, I took to a machine shop and had them do the work.  There is
not much "meat" on the arms and one broke and they made a new one.
Better them than me.

Welte systems have carbon sleeves that easily break in disassembly.
Fortunately, bronze sleeves are available.

By the way, the previous re-builder used oil and grease even on the
three wood pieces in the arms of the bellows.  Oof!

Jeff Davis, Seattle