"Skip Gundlach" skipgundlach at gmail dotcom wrote

I understand and "get" what you are saying about the drivesavers -
but years of use by others, successfully, makes me wonder why the
problems you cite/project don't make it so nobody uses them?

They aren't really a problem by themselves but sort of a band aid
solution for not doing it right in the first place. Of course, most
pleasure boaters, and plenty of boatbuilders, don't want to do it
right. They just want to take stuff out of boxes and bolt it
together. A drivesaver probably won't make things any worse in that
situation, it may even help a little bit with a boost from the placebo
effect.

In the commercial world, the flange on the gear is trued up so that
the outside edge is exactly concentric and the face exactly
perpendicular to the shaft. That flange is then mated to the
propeller shaft flange which is trued up after being installed on the
shaft with the whole thing being turned in a lathe or other fixture.
A male/female pilot or disk; not the bolts, keeps the two halves
concentric.

If you're not going to do this stuff, maybe a drivesaver will help but
it won't be as good as doing it right.

If you do it right, you won't need the drivesaver and it just makes
things more likely to slip.

Still, I wouldn't bother taking the one out of my shaft system except
to make it less of a pain to repack the stuffing box.

--

Roger Long