"Flying Pig" wrote in message
...
"Wilbur Hubbard" wrote in message
news:504a191a$0$62077

Poor Skippy!!! It sounds like your amateur attempt at alignment is doomed
to failure.

Why?

Because there is a lot more to alignment that just centering the shaft in
the log. A perfectly centered shaft can fail to be perfectly aligned with
the transmission output shaft/flange.

IOW, if the two flanges that bolt together are not perfectly parallel both
top to bottom and side to side and everywhere else, when the propeller
shaft is centered in the log there will be a terrible vibration set up as
the two flanges will bind and loosen as they rotate. The only way to get
them perfect is by using two dial gauges, one for each flange and as you
rotate them with perhaps an 18th inch of space between them (in neutral)
by hand both gauges must not move more than a blonde hair.

Sounds to me you are doing the job only halfway, Skippy.


Wilbur Hubbard


Heh. Reading deficit, eh?

We got the shaft centered. That took care of the alignment with the
cutlass. The shaft turns readily, by hand, from the skinny end outside, the
middle, next to the log, and the transmission, where I've got the coupling
mated with the bolts, but not yet tightened, as we've not yet aligned the
engine.

That's what I'm talking about. When you snug up the two flanges (propeller
shaft flange and engine/transmission flange - assuming engine and transmission
are integreal) unless their two flange faces are perfectly alligned snugging
them down together will result is binding and releasing (vibration). Prior to
snugging them down face-to-face you must assure yourself that they are
perfectly parallel both horizontally and vertically. And, keep in mind,
depending upon the flexibility of your old hull, that the relationship may
well change when the boat is back in the water (not that that's EVER going to
happen, LOL!)

It can be rather tricky. Some of the Irwin 43's I helped build working as an
MEP (mechanical, electrical, plumbing) experienced this problem as the hulls
were rather 'flexible' and the alignment was done on the production line. Some
needed to be re-done once splashed.


Wilbur Hubbard