"Wilbur Hubbard" wrote in
anews.com:

"Ian Malcolm" wrote in message
...
"Wilbur Hubbard" wrote in
anews.com:

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

BullPucky!
Its simple enough to get them dead in line with a feeler gauge
between their faces. Simply rotate the two flanges together while
checking the gaps at four points seperated by 90 degrees. (the
measurement points rotate with the flanges). If they neither tighten
or loosen on the gauge finger through a whole turn the angular
alignment is 'dead nuts'.

Sadly, that's only about half the picture. Just imaging the two shafts
not being on the same centerline. Feeler gauges might indicate that
the two flanges were parallel but there STILL would be binding due to
the two flanges being off center - hence the need to use dial gauges.

Look at the illustrations, please. Maybe you're bright enough to
understand what I'm talking about.

Like I said and I still maintain I said correctly, Skippy is only
doing HALF the job. And, apparently this also applies to you as well.

http://www.hellersolutions.com/C350/...llManual10.pdf

Wilbur Hubbard

Well have you got any reputable reference for marine engine shaft
alignment using two dial gauges? Your link above uses feeler gauges.

Also what about static shaft deflection due to its own weight and the
weight of the half coupling? I'd be interested to hear your version of
how to compensate for it in practice.


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Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
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