Autoprop + Shaft Razor
KC9...@gmail.com
proposing to install an H5 Autoprop together with a Shaft Razor rope
cutter. I would like to call upon the collective wisdom of the group
to help me with the following Questions:
Are all the prop shafts on B473s (Yanmar Diesel) 30mm in diameter?
Can a Shaft Razor be mounted with an Autoprop?
On the Autoprop website both the H5-506 and the H5-485 are recommended
for the B473 with a 75 HP Yanmar. Any thoughts on which is
preferable?
Thanks.
John.
Rick Donovan
we had the Westerbeke 63C4 in our 2002 473 and had the Autoprop
H5-485R that was recommended to me by Autoprop. I installed the prop
before spring launch the second season with our boat. our Hurth
transmission had a final gear ratio of 2.71:1. we also had the 30mm
shaft so even though you have the larger Yanmar engine package, my
guess is that Autoprop has the correct prop suggested.
not sure what the difference is between the H5-506 and the H5-485 off
the top of my head, but I am sure a phone call will answer that
question. I also had the shaft razor just ahead of the hub for the
Autoprop and although it is a small area to deal with, the shaft
razor did fit with the required clearances needed to allow the
correct flow of water thru the cutlass bearing and up into the stern
tube.
in my opinion, you only have 2 choices of props to decide from. I
know others here on the list will disagree with that statement and
that is understandable. I am not trying to get a prop war going
either, but for the bigger boats like the 473, I just don't feel the
folding style props are adequately built, again it is my opinion.
my choices, as I saw it, when making this upgrade were Autoprop and
Maxprop. the Max design had been around for many years on large
numbers of boats in our area. those that had used it with zero
problems that I was aware of, they make an excellent product. I had
several folks on this list recommend the Autoprop and that is how I
went.
my decision really came down to this, the Max required assembly of
components as it is installed on the prop shaft. any one of these
pieces were subject to being out of position during assembly and the
end result could be one of the 3 blades not at the same pitch as the
others. add to that possibility there was a 50-50 chance that the
recommended pitch settings from Max, even if you assembled it
correctly, could still be off requiring the boat to be hauled for "an
adjustment" to the final pitch that allowed max engine rpm to be
reached. Max has since come out with an adjustment process that could
be done by a diver with no haul out required that was not available
when I purchased. not sure my decision would be any different today
because you can simply take the Autoprop out of the box and install
it on the shaft. no assembly what so ever needed.
the best feature I have seen in using the Autoprop now for 6 seasons
is its ability to feather to a different pitch for the current
conditions. it is very hard to try to describe and I won't try here
but take a look at their video on the web site. that will do more
justice than I can trying to make my way thru a description of how it
works. at first I couldn't see how this design could possibly work at
all but it does.
we have benefited greatly on light air days when the wind and your
time schedule just don't fit sailing conditions and we are motor
sailing trying to make good time. as the boat speed increases, the
Autoprop continues to feather the blades to a larger pitch than would
be allowed by the Max design. this feature has allowed us to motor
sail at 10+ knots thru the water a number of times, or for the
cruising sailor this feature allows you to drop the engine rpm and
maintain the same boat speed which uses less fuel. it is a win win
situation for the cruiser. if you have plans for racing, the Max
would definitely be a better choice because it has less drag.
my 2 cents worth, sorry guys and gals for what this thread will
likely turn into.
Rick Donovan
Biddeford, Maine
John White
John.
Michel Sirois
I had (untill I got rid of it) a H5-485 and felt it was under propped and
wish I had gotten a 506. I guess it was one of the reason for me to get rid
of it.
As for Shaft Razor there is room for it but without any shaft anode unless
you also put a Drivesaver and keep the shaft the same. Which I did. But I
had an awfull lot of vibration problem even if engine-shaft alignement was
correct. Shaft was thru. We (me, yard managers, and surveyors)came to the
conclusion that the Autoprop was the source of the problem. Autoprop blamed
it on Beneteau's design saying there was lack of shaft support. To certain
extent they were right. There is a rule which says there should be no more
than 11/2 time the diametre of the shaft distance seperating the prop from
the aft of the shaft support. In this case shaft tube which in fact is not
great support compared to a strut.
So the Autoprop was the source of vibration. The lack of support and
relatively small size of the shaft allowed the vibration to be amplified.
I certainly don't want to start another prop war, so if you want more info
on this you can contact me directly at siro...@nb.sympatico.ca or call home
506-546-1800. I going away tomorrow and will be back next tuesday.
Michel
Quasida B473
Michel Sirois
By the way we have the Yanmar 75. I had the Autoprop on untill last year
which means 4 years and over 13000 nautical miles and I bought last year a
VariProp 3 blades. This is a German design which I think is much better
built than the MaxiProp. I had a Maxiprop on my previous boat for 6 years so
I can compare.
Michel
Guy
strut which can work loose (it's held in place by 4 bolts).
The B design has 2 bearings, the cutlass and the dripless. Conventional
rigs have 2 also, a cutlass in the srtut and the stuffing box.
Guy
----- Original Message -----
From: "Michel Sirois" <siro...@nb.sympatico.ca>
To: <Benetea...@googlegroups.com>
Sent: Wednesday, June 04, 2008 4:25 PM
Subject: {Beneteau Owners} Re: Autoprop + Shaft Razor
|
Michel Sirois
The shaft tube sticks out of the skeg about 5 inches and is absolutly un
supported for all that lenght. This rather thin fiberglass tube and also
thin SS sleave over it is bendy and in no way comparable in rigidity and
support to a thru bolted strut support in vertical plane, sideways we could
argue on it...
Any way the point is that a long unsupported lenght of 30mm (small) shaft is
prone to wipping with a vibration source at the tip of it. Plus the
Autoprop is much heavier than Maxi, Vari or Jprop.
Michel
Guy
indeed a support. It's design is similar to a cutlass with groves for water
lubrication and lands for support. It provides as much support as a
stuffing box.
I've seen several struts work loose over the years.
Yes, the shaft is unsupported 4=- inches aft of the cutlass. But on most
props I've insalled, fixed, feathering, folding, etc. there is only a small
gap of exposed shaft. Not enough even for a small zinc.
When I replaced my shaft this spring, I added 1/2" to provide for
installation of a thin collar zinc.
I do not think the stainless tube is flimsy; the fibergalss liner is
problematic if you have line wraps or other issues.
Rick Donovan
did you have the drive saver installed at the same time as the
Autoprop?? or did you have some time to use the Autoprop without the
drive saver in place?? just curious about when your vibrations appeared.
I purchased a drive saver at the same time as purchasing the Autoprop
but decided to not install it because of the length of exposed shaft
measurements that you quoted in your last email of about 1.5 times
the diameter before getting into a situation where vibration/shaft
flex could become a problem. I wonder if that is why I did not have
the vibration problem that you experienced?
I think you have it exactly right, on the 5 inches or so of the shaft
tube that sticks out of the skeg because on top of that tubing being
very thin, the cutlass bearing is out at the free end of this stern
tube. it would have a bit of leverage to work with if the prop did
start to wobble before any support is given where the tube enters the
skeg. if you were to use the distance from the back of the skeg where
the actual support is out to the prop hub as your measurement, that
distance would certainly well exceed the estimated ratio of 1.5 times
diameter. add in the 1/2 inch or so more from the thickness of the
drive saver and the prop is really far away from the actual support
of the back edge of the skeg area.
in the end I had to assume that the engineers at Beneteau knew more
about these sorts of things than I do, so I chose not to aggravate
the situation by installing the drive saver. I thankfully never had
the vibrations that you are speaking of on our 473.
Rick Donovan
Biddeford, Maine
Michel Sirois
I did in fact install the Drivesaver one year after the Autoprop. Without it
I had some vibration but it was tolerable and except around 2600-2700 rpm.
With the Drivesaver it became worst, started earlier and only got worst at
higher rpm.
The prop definitely had a vibration problem. When contacted initialy they
blamed many different things but the prop. Then after two years or so A*B
Marine had nothing to offer but to send the prop to UK at my expense
because by then after all the time trying to troubleshoot (check alignement,
check shaft,...) and changing the bearings it became obvious that the blade
balancing had to be checked. But with theses self positioning non geared
blades how do you do that. After extensive search in Eastern Canada and
Eastern US I did not find anybody willing to do it.
Oh and by the way the prop was never hit, marked or repaired. So you see
why after over four years of putting up with this I simply got rid of it
for a prayer...
Best
Michel
----- Original Message -----
From: "Rick Donovan" <richard....@verizon.net>
To: <Benetea...@googlegroups.com>
Sent: Wednesday, June 04, 2008 8:52 PM
Subject: {Beneteau Owners} Re: Autoprop + Shaft Razor
>
Michel Sirois
You must have a different system that I have. I don't know what year or
model you have?
I had mine disconnected numerous time and also taken out completly to make
shure shaft was straight. I had initialy the Volvo dripless and then
changed for a PSS. I can assure you that on my boat there is no such thing
as a or similar to a cutlass bearing in the front. When I disconnect the
coupling from the transmission the shaft drops unsupported for a 1/4 in or
so.
Guy
short cutlass bearing; I have the old one in the garage and I'll measure the
length. If it dropped 1/3 or so, it wa sprobably out of alignment anyeay.
Nuff said
John P. McLaughlin
them. Great prop, but the vibrations got to be unbearable. I put it on in
July, took it off when I hauled it in November. I had discussions with them
through the winter during which they blamed a lot of things other than the
prop. They took it back in March with a full refund. Now I have a MaxProp.
It is great too and no vibrations. It was a hassle but A&B did the right
thing but I hesitate to buy a Gori for my boat.
--------------------------------------------------
From: "Michel Sirois" <siro...@nb.sympatico.ca>
Sent: Wednesday, June 04, 2008 8:21 PM
To: <Benetea...@googlegroups.com>
Michel Sirois
as simple as that!!!
As for alignement, well it was checked by a marine mechanic in Norfolk, and
was said to be true.
Your right...nuff said.
Rick Donovan
based on what you have written and tried for a cure to the vibration,
I think that I would have come to the same conclusion as you have,
there is a problem with your Autoprop and it is likely a balancing
problem or possibly a blade shape or position problem. either way, if
AB Marine wouldn't back the problem, as I think they should have from
what you have written, you really didn't have any choice but to make
a change. sorry to hear that you needed to go thru all. I assume that
the new prop is working well for you after going thru all this extra
time and cost?
like Cap mentioned, I also had a recall during the second season on
my Autoprop. it was for some sort of a problem with a seal location
in the pivot points of each blade. as I recall, the seal was not
correctly positioned and would allow sea water to wash the grease
from the bearings and they would suffer a premature failure that if
left long enough could allow a blade to come off. that would really
ruin your day, lol.
I spoke with AB Marine about what needed to be done and because there
was no immediate danger, I decided to remove the prop over the winter
and send it to them. They provided a shipping account to allow me to
box the prop up and send it thru their shipper. I delivered it to the
closest shipper they used all at their cost, about 15 miles away. the
prop went to England, had the repairs done and was sent back to me in
about 3 weeks, it arrived at my door all at no cost to me. I thought
that was pretty good service in todays world of generally bad
customer service. I did not notice any difference from before the
repair to after the repair other than the blades rotation was
slightly stiffer by hand than before the repair.
I believe that you are correct in saying it would be very difficult
to balance this prop as an assembly. It would seem to me that the
only way to get it right would be to match up the weights of the
individual moving parts like each blade, and then the hub itself all
while disassembled. the Autoprop, or any big prop for that matter, is
heavy enough that the manufacturer must consider balancing as a
potential problem when being assembled. I am hard pressed to believe
that any prop manufacturer doesn't take that into consideration
during the building process.
do you remember what your final gear ratio is on the transmission??
our was 2.71:1 with a max engine rpm of 3600. if my math is correct
that means our prop is spinning at about 1328 rpm when we use full
throttle. with the prop weighing something on the line of 25 pounds,
that is more than enough weight to be a big problem if the balance is
not quite close to perfect. if by chance the Yanmar engine package
spins the prop shaft at a higher rpm maybe that is a possible
explanation to you having this trouble when others did not.
Michel, I also remember that when the shaft coupling was disconnected
from the transmission, the shaft would drop at least a 1/4". I know
this from checking and adjusting the shaft alignment myself a couple
of times. alignment is not as simple as sliding the shaft towards the
coupling and checking between the flanges with feeler gauges as is
common to do because of the lack of support at the Volvo shaft seal
at the engine end of the shaft. even if there is a "support surface"
inside the Volvo seal assembly, I have never seen one disassembled,
the whole rubber unit that makes up the seal is very flexible. if you
aligned to that hanging position, I can't imagine the problems that
would be created. aligning the shaft in that lower/hanging position
is definitely not the correct way on our boat. maybe a smaller
diameter shaft in smaller boats doesn't deflect the Volvo seal
assembly from its weight like it will with the heavier shaft of the
473?? just a thought trying to find an explanation for the difference.
Rick Donovan
Biddeford, Maine
>
>
Surfer Gil
It is a great prop as it can be adjusted for fwd and reverse pitch in
the water, serviced (lube and anode) in the water and does not have as
many moving parts as the Max or Auto prop. When it was serviced by
Nanny Cay in the BVI, they seemed to have re-installed in with the rev
pitch way off as prop walk was huge. A quick 10 min dive and
adjustment and prop walk is almost gone.
http://www.martec-props.com/autostream.htm
Gil
Michel Sirois
Thanks for your words.
I'm in fact very pleased with the VariProp. I have now absolutely no
vibration problem but I Do miss the motor-sailing advantage of the Autoprop.
Michel
----- Original Message -----
From: "Rick Donovan" <richard....@verizon.net>
To: <Benetea...@googlegroups.com>
Sent: Thursday, June 05, 2008 8:35 AM
Subject: {Beneteau Owners} Re: Autoprop + Shaft Razor
>