[ Don Barton wrote in 120123 MMDigest:

> On two separate occasions the ends of two wooden connectors
> have split out.

Don,  My take on this is that it was just a bad day in the factory.
One connector end failing is one thing, but two failures begins to
sound like a materials or workmanship issue.  It could be instructive
to lightly sand the black finish off of the sides of the connectors
to see which way the wood grain is running.

The grain should be parallel to the length of the connector.  If it
is perpendicular, or even greater that 45 degrees from the length
the ends will probably break out pretty cleanly, but could probably
be successfully repaired with the application of an aggressive
wood-compatible adhesive such as "Gorilla" glue.

If the ends are badly splintered, it would indicate the grain is
properly aligned but something else has happened such as a mechanical
blockage that kept the feeder bellows from completely collapsing or
opening.

Were the failures on the ends toward the feeder bellows or at the
"spider" eccentric?  Badly splintered ends are probably not repairable
and would have to be replaced.  Fortunately, I believe the connectors
of "B" pumps are identical to those in (at least) late "A" pumps, so
the supply of replacements should be good (I have a bunch myself), but
be sure to measure the over-all length to insure interchangeability.

In any case, the spring adjustments on the wedges and the pre-existing
knock are, in my view, most unlikely to have contributed to the
problem.  Even if tightened to their maximum compression, the amount of
pressure the springs exert laterally through the wedges should be far
below the failure point of the wood.  Their purpose is to compensate
for mechanical wear of the felt bushings, and this force would bear on
the "inside" surface of the bushing, not the end of the connector
anyway.

If it was his first day in the wood shop, the worker might have thought
he was saving the company some money by using up scraps of wood that
might have been big enough for the pattern but had the grain in the
wrong direction.  My mind's eye can picture an adjustable, race-track
shaped band (stainless steel?) the width of the connector, with cut-out
slots top and bottom for the adjusting wedge to protrude through, sort
of like worm-drive hose clamp, but this is probably over-kill.

Also, be prepared: you have six more ends that may eventually fail if
my grain theory is correct.

John Grant