Thread: Help for Martin
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Bob Crantz Bob Crantz is offline
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First recorded activity by BoatBanter: Dec 2006
Posts: 330
Default Help for Martin


"Capt. Rob" wrote in message
ups.com...
Martin, this is what Mark explained to me and our head mechanic agrees
100%.

Typically the shaft coupler that connects to the tranny is a flange.
This is often held with a series of bolts around the edge. In the case
of a fouled prop, especially with a heavy line, the prop and shaft
become wrapped. The engine labors and if it's not cut in time some of
these bolts shear away. If enough of them shear away the forces on the
flange become uneven and the shaft begins to wobble a little or a lot.
The shaft will rarely be true after such an event and it can all occur
in seconds, well before an emergency stop How often does this happen?
When, according to folks I spoke to at my shop, they've seen it many
times, especially on older boats where the flange has seen plenty of
corrosion. They've seen it happen on powerboats as well.
The Drivesaver loads are far below those of the bolts on the flange
and would prevent this by breaking first.

I hope this helps, Martin. But if it doesn't please contact Drive
Saver and describe this scenario above to them if you have any doubts.
Unlike you I work closely with the largest full service yard in the
area, so I have real world insight into SOME issues.
I have no doubt that a lot of know-it-alls will chime in here, but
they are ALL full of crap. Call the company and talk to them yourself.

Cheers,


RB
35s5
NY


The drivesaver is a rubber spring. It still has to drive a propeller, so
they forces from the engine are transferred to the prop otherwise the boat
doesn't go or it goes much less efficiently. Simple physics.

The static loads on the bolts are the same as the loads on a solid flange,
otherwise the boat would go slower. Simple physics.

The rubber flange compresses and rebounds when the loads change, just like a
spring should work. Simple physics.

The compression of the flange expands the forces due to load change in time
and reduces the acceleration forces on the drive train. Simple physics.

When the rubber is fully compressed it no longer acts as a spring, it is
virtually the same as a solid flange. Simple physics.

Call Drivesaver because Robbie can't explain this to you. Simple physics.


Robbie works in the real world and has INSIGHT into stereos, boats, cars,
microcontrollers and yet when it comes down to analyzing anything using
simple essentials with his own knowledge and brain, he runs for the opinions
of others!

40 years in the same apartment as an only child - guess who raised a
dependent adult-child?


Cobb Reprogrammers not reburning flash! If they could do that they would be
making hundred of millions in the ICE (in-circuit emulator) market. Does the
Cobb Reprogrammer also shine black colored light? Stay cool by absorbing
heat?

You dolt!