Help for Martin
 

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

Help for Martin
 

"Capt. Rob" wrote:

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.

So the flanges in Bennys are undersized? How many bolts sheared in your
coupling? If the bolts regularly sheared in the scenario you describe,
there would be no market for the DriveSaver.

Back to your personal story (and I do mean story), first "our prop
fouled something", later we read "According to the head mechanic, the
damage was instant and the decoupling also instant". Now you are asking
us to believe that you caught "a heavy line" a couple of feet below the
surface, that the tow boat bumped into when rescuing you! Keep digging
Bob, soon you'll have a well.

I can't believe you didn't take a whole series of photos of the mangled
drivesaver, oh well, give it time. I', sure you'll manage to Google
something up.

I'm off to the local gizmo shop, I need a new Blarney Meter.

Cheers
Marty
------------ And now a word from our sponsor ---------------------
For a secure high performance FTP using SSL/TLS encryption
upgrade to SurgeFTP
---- See http://netwinsite.com/sponsor/sponsor_surgeftp.htm ----

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!

Help for Martin
 

Now you are asking
us to believe that you caught "a heavy line" a couple of feet below
the
surface, that the tow boat bumped into when rescuing you! Keep
digging
Bob, soon you'll have a well.


I'm not asking you to believe anything. You SAID that the drivesaver
ONLY protects the tranny and engine and I said WRONG. I've provided
scenerio where the drivesaver can save a shaft. Worse for you it makes
perfect sense as I described it.
If you want to claim that Drivesaver and the mechanic are lying go
right ahead.
Heart of Gold fouled a submerged object, probably a log. Shaft is bent
and the engine and tranny appear to be fine. Thanks, Drivesaver!


RB
35s5
NY

Help for Martin
 

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



What a dope. You assume that the compression is at maximum under
typical load. It's not. And of course you fail to consider maximum
load of the entire assembly installed vs. maximum loads without it.
The bolts for the drivesaver are not designed to handle as high a load
as the bolts on the flange, dopey!
Simple physics and you failed!

BWAHAHAHAHAHA!


RB
35s5
NY

Help for Martin
 

"Capt. Rob" wrote in message
ups.com...
When the rubber is fully compressed it no longer acts as a spring, it
is
virtually the same as a solid flange. Simple physics.



What a dope. You assume that the compression is at maximum under
typical load.

You assume I said that. Read what I said.


It's not. And of course you fail to consider maximum
load of the entire assembly installed vs. maximum loads without it.

This makes no sense.


The bolts for the drivesaver are not designed to handle as high a load
as the bolts on the flange, dopey!

What flange in particular? Ever hear of a woodruff key? Guess not!


Simple physics and you failed!

Practical real world experience, physics and you fail at both!

Woodruff Key Smackdown!

Help for Martin
 

You assume I said that. Read what I said.


Oh, so does it see max compression under typical load or not?? Hmmmm?


It's not. And of course you fail to consider maximum
load of the entire assembly installed vs. maximum loads without it.
This makes no sense.


Sure it does. It's just beyond you to see the obvious. Bottom line: If
loss of the flange bolts can lead to shaft wobble and bend and the
drivesaver can prevent that, then the drivesaver can SAVE a shaft.
If you ever get a boat with an inboard...or any boat at all...this
info could save you money!


RB
35s5
NY

Help for Martin
 

"Capt. Rob" wrote:

Now you are asking
us to believe that you caught "a heavy line" a couple of feet below
the
surface, that the tow boat bumped into when rescuing you! Keep
digging
Bob, soon you'll have a well.

I'm not asking you to believe anything. You SAID that the drivesaver
ONLY protects the tranny and engine and I said WRONG. I've provided
scenerio where the drivesaver can save a shaft. Worse for you it makes
perfect sense as I described it.

No, you provided a load of malarkey; please try to explain how you can
produce shear forces on one or two, or three bolts in a coupler but not
on the remainder. It can't be done


If you want to claim that Drivesaver and the mechanic are lying go
right ahead.

I don't claim that either are lying, I claim that you are.

Heart of Gold fouled a submerged object, probably a log. Shaft is bent
and the engine and tranny appear to be fine. Thanks, Drivesaver!


Hey, that's exactly what Drivesaver claims to do, "save the engine and
the transmission while sacrificing the propellor and shaft."

I knew you'd come around!

Cheers
Marty

Help for Martin
 

"Capt. Rob" wrote in message
oups.com...

Sure it does. It's just beyond you to see the obvious. Bottom line: If
loss of the flange bolts can lead to shaft wobble and bend and the
drivesaver can prevent that, then the drivesaver can SAVE a shaft.
If you ever get a boat with an inboard...or any boat at all...this
info could save you money!


Didn't your drivesaver lose a few bolts?

Isn't your shaft bent?

Why am I not seeing the obvious?

Help for Martin
 

Didn't your drivesaver lose a few bolts?

Isn't your shaft bent?


Why am I not seeing the obvious?



Cuz you can't understand what you read past a single post!
I said that it can prevent damage in a line fouling case which is
quite different from striking a log.
Bob, seriously. You're slow.
Very
Slow.
S-L-O.....W



RB
35s5
NY

Help for Martin
 

"Capt. Rob" wrote:

Didn't your drivesaver lose a few bolts?

Isn't your shaft bent?

Why am I not seeing the obvious?

Cuz you can't understand what you read past a single post!
I said that it can prevent damage in a line fouling case which is
quite different from striking a log.
Bob, seriously. You're slow.

Well, golly Bob, you posted that you "fouled" your prop, now you're
saying you struck a log. You may have lied the first time around, you
may have lied about the log, or more likely lied about both and once
again demonstrated that you don't even have a decent grasp of basic
nautical terminology.

Cheers
Marty

Help for Martin
 

* Martin Baxter wrote, On 7/13/2007 7:49 AM:
"Capt. Rob" wrote:
Didn't your drivesaver lose a few bolts?

Isn't your shaft bent?

Why am I not seeing the obvious?

Cuz you can't understand what you read past a single post!
I said that it can prevent damage in a line fouling case which is
quite different from striking a log.
Bob, seriously. You're slow.

Well, golly Bob, you posted that you "fouled" your prop, now you're
saying you struck a log. You may have lied the first time around, you
may have lied about the log, or more likely lied about both and once
again demonstrated that you don't even have a decent grasp of basic
nautical terminology.

Its fascinating how RB's stories evolve with each telling. First he
"fouled" something while leaving the marina, then he "hit" something,
then the towboat hit something. There was, of course, no mention of
trying to remove the obstruction. One might guess that if two vessels
hit an obstruction in an entrance channel, some effort would have been
made to remove it. But obviously not in booby's world.

Help for Martin
 

Jeff wrote:

* Martin Baxter wrote, On 7/13/2007 7:49 AM:
"Capt. Rob" wrote:
Didn't your drivesaver lose a few bolts?

Isn't your shaft bent?

Why am I not seeing the obvious?

Cuz you can't understand what you read past a single post!
I said that it can prevent damage in a line fouling case which is
quite different from striking a log.
Bob, seriously. You're slow.

Well, golly Bob, you posted that you "fouled" your prop, now you're
saying you struck a log. You may have lied the first time around, you
may have lied about the log, or more likely lied about both and once
again demonstrated that you don't even have a decent grasp of basic
nautical terminology.

Its fascinating how RB's stories evolve with each telling. First he
"fouled" something while leaving the marina, then he "hit" something,
then the towboat hit something. There was, of course, no mention of
trying to remove the obstruction. One might guess that if two vessels
hit an obstruction in an entrance channel, some effort would have been
made to remove it. But obviously not in booby's world.

Indeed, I sometimes forget that the Boobster lives in the Matrix.

Cheers
Marty

Help for Martin
 

No, you provided a load of malarkey; please try to explain how you
can
produce shear forces on one or two, or three bolts in a coupler but
not
on the remainder. It can't be done



Bwahahahahahahaha!!! Right, Martin.....all of the loads and breakaway
points are identical, right? So when this type of gear fails ALL of
the bolts shear away in the same instant!
BWAHAHAHAHAHHAHAA! Yeah, okay, sure thing, Martin. You go on and
believe that.


RB
35s5
NY

Help for Martin
 

"Capt. Rob" wrote:

No, you provided a load of malarkey; please try to explain how you
can
produce shear forces on one or two, or three bolts in a coupler but
not
on the remainder. It can't be done

Bwahahahahahahaha!!! Right, Martin.....all of the loads and breakaway
points are identical, right? So when this type of gear fails ALL of
the bolts shear away in the same instant!

If you rotate one flange against the other sufficiently far enough to
shear one bolt, you're going to shear them all, it's really pretty
simple. Besides I don't believe the weak point here is the bolts, they
represent a far greater tensile strength than the woodruff key, or keys
depending on your drive arrangement.

Cheers
Marty

Help for Martin
 

If you rotate one flange against the other sufficiently far enough to
shear one bolt, you're going to shear them all, it's really pretty
simple.



Marty. Think for a moment. A propeller slices and chews into a heavy
submerged log. MAYBE all the bolts shear off and the engine/tranny is
free of the shaft. Or MAYBE one bolt hangs on and now the flange
wobbles.
= Bent shaft.
Talk to a mechanic, Martin. Or the folks at drivesaver. Not only does
this happen, it happens often enough that our adjuster knew about it.
We had a nice long talk about drippless packing as well, since ours
failed on impact.


RB
35s5
NY

Help for Martin
 

On Sat, 14 Jul 2007 00:35:27 -0000, "Capt. Rob"
wrote:

If you rotate one flange against the other sufficiently far enough to
shear one bolt, you're going to shear them all, it's really pretty
simple.



Marty. Think for a moment. A propeller slices and chews into a heavy
submerged log. MAYBE all the bolts shear off and the engine/tranny is
free of the shaft. Or MAYBE one bolt hangs on and now the flange
wobbles.
= Bent shaft.
Talk to a mechanic, Martin. Or the folks at drivesaver. Not only does
this happen, it happens often enough that our adjuster knew about it.
We had a nice long talk about drippless packing as well, since ours
failed on impact.

Bob, make sure you get the proper torque rating on the new Drivesaver.
These things were originally designed for +200hp boats.
I've read where they don't always break at the lower torque found
on sailboat drivetrains. This may be why your shaft bent.
Here's a link to an example.
http://lists.samurai.com/pipermail/t...er/097202.html
The company may have addressed the torque rating issue with more
models now.
There are also electrical implications to be considered due to
isolation, but I can't speak to that.
From reading your posts here, you generally rely on yardbirds to do
things right, but also know they often don't.
If you examine the Drivesaver, you'll see that it provides the bolts
to the output flange on one side of it, and separate bolts to the prop
shaft flange on the other side. When the torque rating is exceeded
(the prop digging in a log, or a line fouling the shaft eg,) the
plastic should shatter, completely disconnecting prop shaft from trans
output. If all works well, no damage has been done. The shattered
Driversaver parts can be removed from the flanges, the prop shaft can
be pulled forward and the flanges bolted together as they would be
with no Drivesaver installed. You're back in business.

--Vic

Help for Martin
 

On Jul 14, 2:23 pm, Vic Smith wrote:
On Sat, 14 Jul 2007 00:35:27 -0000, "Capt. Rob"
wrote:





If you rotate one flange against the other sufficiently far enough to
shear one bolt, you're going to shear them all, it's really pretty
simple.

Marty. Think for a moment. A propeller slices and chews into a heavy
submerged log. MAYBE all the bolts shear off and the engine/tranny is
free of the shaft. Or MAYBE one bolt hangs on and now the flange
wobbles.
= Bent shaft.
Talk to a mechanic, Martin. Or the folks at drivesaver. Not only does
this happen, it happens often enough that our adjuster knew about it.
We had a nice long talk about drippless packing as well, since ours
failed on impact.

Bob, make sure you get the proper torque rating on the new Drivesaver.
These things were originally designed for +200hp boats.
I've read where they don't always break at the lower torque found
on sailboat drivetrains. This may be why your shaft bent.
Here's a link to an example.http://lists.samurai.com/pipermail/t...ing/2005-Novem...
The company may have addressed the torque rating issue with more
models now.
There are also electrical implications to be considered due to
isolation, but I can't speak to that.
From reading your posts here, you generally rely on yardbirds to do
things right, but also know they often don't.
If you examine the Drivesaver, you'll see that it provides the bolts
to the output flange on one side of it, and separate bolts to the prop
shaft flange on the other side. When the torque rating is exceeded
(the prop digging in a log, or a line fouling the shaft eg,) the
plastic should shatter, completely disconnecting prop shaft from trans
output. If all works well, no damage has been done. The shattered
Driversaver parts can be removed from the flanges, the prop shaft can
be pulled forward and the flanges bolted together as they would be
with no Drivesaver installed. You're back in business.

--Vic- Hide quoted text -

- Show quoted text -

Interesting post, Vic...thanks!



RB
35s5
NY