[C320-list] Blade falls off of Autoprop propeller!

Tue Sep 12 07:28:06 PDT 2006

My H5 BB was delivered thes April with the same documentation Bruce 
received.  I did notice on the AB website that they do not have the torque 
information for the ball bearing model which does not require regular 
greasing like the other AutoProps do.
----- Original Message ----- 
From: <bruceheyman at cox.net>
To: "C320-List" <c320-list at catalina320.com>
Sent: Tuesday, September 12, 2006 8:50 AM
Subject: Re: [C320-list] Blade falls off of Autoprop propeller!


> Jon,
> In the information that I got from the PO I found an envelope with the SN 
> of our H5BB on the outside, a letter from Steve Armatage and a couple 
> pages on how to maintain the prop, including how to adjust the bearings 
> (tourque down to 14 ft lbs or 18 NM and then back of 1/4 turn).  The most 
> dificulty I had was tightening the lock nut with out it adjusting the 
> tension on the bearings.
>
> I would be happy to make a copy and send to you if that would help.
> Bruce
> Somerset 671 SoCal
> Sent via BlackBerry from Cingular Wireless
>
> -----Original Message-----
> From: jonvez at comcast.net
> Date: Tue, 12 Sep 2006 13:09:28
> To:C320-List <c320-list at catalina320.com>
> Subject: Re: [C320-list] Blade falls off of Autoprop propeller!
>
> Larry,
>
> Did the procedure you mention from AP come with the propeller? I don't 
> believe I received the procedure you are referring to...
>
> Regards,
>
> Jon Vez
>
> -------------- Original message -------------- 
> From: "WindSwept" <c320_windswept at sbcglobal.net>
>
>> Bruce,
>>
>> I'll respond here to a couple of things.
>>
>> You took a hit on the 240 Buicks so I won't comment on that. The correct
>> unit on the torque is 14 ft-lbs or 18 NM per the instructions I received.
>> My torque wrench is calibrated in inch pounds and NM. 14 ft pounds is 168
>> inch-pounds. Any of the three will work.
>>
>> The website doesn't really talk about bearing adjustment. It really just
>> adresses cleaning out of the bearings.
>>
>> This weekend I checked the bearing adjustment and followed the AB Marine
>> procedure where you back off the retaining cap by 1/4 turn. I also have 
>> the
>> procedure recommended by Steve, but decided to go with the procedure
>> provided by the designers and manufacturers over the distributor. I have 
>> no
>> reason to believe that Steve's procedure wouldn't be perfectly fine and 
>> it
>> is easier to follow.
>>
>> When the bearings are adjusted using the procedure provided by the 
>> designers
>> of the autoprop, the blades spin smoothly and there is just a small 
>> amount
>> of play in the bearings.
>>
>> Larry
>> ----- Original Message ----- 
>> From:
>> To: "C320-List"
>> Sent: Saturday, September 09, 2006 6:44 PM
>> Subject: Re: [C320-list] Blade falls off of Autoprop propeller!
>>
>>
>> > Larry,
>> > Sorry you lost the blade! I'd be very interested in how freely the 
>> > blades
>> > rotate when you get your prop back from the factory. I just rebuilt 
>> > ours
>> > but on the direction of Steve Armitage I did NOT follow the original
>> > instructions. The original instructions call for you to tourque down on
>> > the adjustments for each blade to 14 nm (I know I have the number right
>> > but not sure about the units) and then back off 1/4 turn. Steve told me
>> > to just tighten them down until there was no play in any direction and 
>> > the
>> > blades still rotate freely. The rebuild kit was about 240 buicks and
>> > fairly easy to do. Hardest part was getting everything good and clean. 
>> > I
>> > also have the H5BB so no grease.
>> > Bruce
>> > Somerset 671 SoCal
>> > Sent via BlackBerry from Cingular Wireless
>> >
>> > -----Original Message----- 
>> > From: "Robert E. Sloat"
>> > Date: Sat, 9 Sep 2006 09:41:36
>> > To:"C320-List"
>> > Subject: Re: [C320-list] Blade falls off of Autoprop propeller!
>> >
>> > Check out their website at http://ab-marine.com/. There is all kind of
>> > installation information and
>> > maintenance procedures for the various model Autoprop propellers. Mine 
>> > is
>> > the H5 model which does not require any greasing. For the models which
>> > require greasing, they suggest every 2 years. The installation
>> > instructions
>> > for my prop suggest rotating the blades at haul out to make sure they
>> > freely
>> > move and gives information on bearing replacement kits when needed.
>> >
>> >
>> >
>> > ----- Original Message ----- 
>> > From: "WindSwept"
>> > To: "'C320-List'"
>> > Sent: Saturday, September 09, 2006 8:59 AM
>> > Subject: [C320-list] Blade falls off of Autoprop propeller!
>> >
>> >
>> > A funny thing happened on the way to the ship yard this spring for my
>> > semi-annual bottom job. Well maybe not so funny.
>> >
>> > Carla and I spent the night at anchor in a cove about 1/2 mile from the
>> > yard
>> > the prior to dropping off WindSwept.
>> >
>> > After hauling anchor when we tried to motor over to the yard the boat
>> > shook
>> > terribly at any RPMs above idle.
>> >
>> > We quickly anchored again and I dove below the boat to find out what 
>> > was
>> > wrapped around the prop, but was amazed to find that one of the three
>> > blades
>> > of my Autoprop was just......missing!
>> >
>> > We managed to sail to the yard which is located up a narrow channel and
>> > moor
>> > in the haul up slip. Luckily the wind was from a favorable direction.
>> >
>> > To make a long story shorter, I had the fixed three blade that came 
>> > with
>> > WindSwept reinstalled and sent the Autoprop to AB Marine for analysis 
>> > and
>> > repair. The prop had to be sent back to the factory in the UK so the
>> > engineers could look at it and a new blade could be fabricated.
>> >
>> > The reason for the failure was that the bearings were excessively worn
>> > causing too much torque to be applied on the mechanical fastenings that
>> > hold
>> > the blades on.
>> >
>> > At this point I think it is relevant to mention that I had purchased 
>> > the
>> > Autoprop used about 7-8 years ago from a 320 owner who had traded up. I
>> > do
>> > not believe I received all the paperwork that one would normally 
>> > receive
>> > with a new Autoprop. This paperwork discusses the need to inspect and
>> > adjust the bearings at each haulout. AB Marine sells a kit for this
>> > purpose.
>> >
>> > I was upset with AB Marine as through the years I have had many
>> > discussions
>> > on this subject and even though I asked about maintenance, this was 
>> > never
>> > mentioned. In their defense, they probably thought I had the original
>> > instruction sheets for installation and maintenance. As an engineer I 
>> > was
>> > amazed that I didn't need to do any maintenance on a bearing in this 
>> > type
>> > of
>> > service. The autoprop had been on WindSwept for four years without
>> > maintenance before the failure occurred.
>> >
>> > The point of all this is that I think this was a preventable situation 
>> > had
>> > I
>> > know to inspect the bearings for excessive looseness and adjust every 
>> > year
>> > or two as needed.
>> >
>> > I plan on having the Autoprop put back on in a couple of weeks as I can
>> > definitely say it really improves boat speed and handling in all
>> > situations.
>> > I will inspect it annually and disassemble and adjust bearing 
>> > clearances
>> > every other year at a minimum.
>> >
>> > I wanted to share my experience with others in the hopes that you don't
>> > experience the same problem. In another situation it could have been 
>> > much
>> > more disastrous.
>> >
>> > Larry
>> > WindSwept C320 #246
>> >
>> >
>> >
>>
>>
>>
>