Autoprop ?

[dkall]

AutoProp update:

On the 14th I spoke with the Engineer David and has reported above that he would get back to me in 2 days, I never received a reply. So the following Friday I emailed him and said that if they were not going to figure a calculation of getting a 20" prop just send me a box so I can return the one I have for a refund. If they want to send me a 20" prop to test I will and either return one or two. I never received a response.

Monday (yesterday) I called England again and am now asking for return information. Dave said "Right O" he would work on my prop problem today and email me. I never received an email. I did email him a quotation from the CEO Adrian that he said they would refund our money if things didn't work out. In the email I also said that I've not been privy to any propellor specs that show an inch and a half clearance on a 21" prop to be the target range and I don't want to keep this size prop when it's not functioning correctly "on my boat". I never received an email from him.

I called this am to get the information on returning the propellor and David was "at the factory". I spoke with Toby who's position is a designer. The individual that answered the phone said she couldn't help me but sent me to Toby.

Toby said he couldn't help me but said he would make sure David received my phone number and call with the information. I'm wanting to return the propellor for a refund and I indicated such.

[GordMay]

Originally Posted by dkall

AutoProp update:
... In the email I also said that I've not been privy to any propellor specs that show an inch and a half clearance on a 21" prop to be the target range and I don't want to keep this size prop when it's not functioning correctly "on my boat".

You’re right to be suspicious. The normally recommended 15% (of prop. dia.) clearance between propeller tip and hull would require at least 3-5/32" (to > 4") clearance on your 21" prop.

The distance from the tip of the blade to the hull should be 0.15 to 0.2 times the blade diameter. If it is less than that, you will almost always experience hull slap, knock, and/or vibration.

A 21" Prop’ should be installed on a 1.4" -to-1.75" diameter shaft (not smaller than 15:1, but 12:1 ratio preferred)

[Alan Wheeler]

I am very disapointed by their lack of help. It is indeed very poor. I hope in your correspondence with them, that you have included links to here, so as they can see the bad rap they are getting.

[dkall]

I just got off the phone and email with them today. They now appear after me asking for a refund or because they believe it that it would work with a 19.8" prop (they use mm's actually) but that I beleive will solve my issues. They did want me to send back the prop I had but I asked them if they could send it here as else I had to hire a diver twice to switch. I received an email later then saying they would indeed send me the prop and I was to then send them the larger one back. So at this point I'm going with their switch out. Davids (the engineer) data suggest that with this prop at high rpms there might be some noise (he didn't say whirl) and that their might be some cavitation. We'll it can't be worse than anything I've had. Now it's a wait to get the prop and I hope above all hopes that all works as now planned. I will let the board know when I've recieved the prop and switched out any differences. I do appreciate the support and knowledge this board has provided. Thanks.

[jose r vigil]

Hello AUTOPROP victims

My situation is similar to other buyers as right now I'm trying to get a cash back after eight months of nightmare.

I have brought an AUTOPROP H 6 534 in the boat show">Miami boat show and since the installation in October 2006 I have been trying to resolve the strong vibration problem. Vibration and yes,,,,, whirling started at 1600 rpm

After some 5000 Euros of bills in yards, Engineers, Bearings, Metal shops and others I wrote an E mail to David at the UK factory four weeks ago.

Last week I received his first reply requesting my cellphone to call me.

Too much.......

Is that what you can call customer support?. I'm busy whats wron with e mail...I'm giving up

I have been misleaded by geoff the US rep. as he said we have a shaft whipping problem.

After eight months of reading books and trials I can assure you the problem is the Propller and NOT the shaft.

That misleaded information cost me 5000 Euros in Audax shipyard in Palma, in part because I was not listening those who told me that the problem is the prop.

For the record my yacht is HANSE 531

I have post a similar warning on Hanse yacht owners forum. My intention is to prevent others to suffer my via crucis.

I'm consideringnow a GORI 3 blade or a VOLVO 4 blade.

Any suggestions?

Thanks in advance

Great idea we have forums to communicate

JOSE

SY ZEN

PALMA

[Alan Wheeler]

Thanks for your post Jose. Wow, having two props doing the same thing is a little worrying.
It makes me think about a comment I made way back earlier in this thread after seeing the video. And I find my self leaning back toward that original view. I think the issue is more likely one or two blades not deploying properly and placing enormouse load on one side of the shaft causing that wip. Why improper deployment I don't know. But if there are two now with this fault, then I bet there are more out there and I wonder if there is hard work clutching at straws going on in the background at Bruntons, trying to work out an issue.
What I don't get is why the haven't sent a techy guy to any of these boats to take a look. It could be a very simple fault of one blade not having identical pitch to the others. Unless this issue is bigger than we realise and they have checked a thought out like that and found it not the problem. Hmmm, only talking to myself, speculating and causing possible rumours, so I better shut up now.

[CARL]

I installed an auto prop in late 2006, the boat deff sails faster she stops better,there is as much prop walk as ever,my cruising speed is slightly down,and i had to fit a shaft brake which hiked up the cost the engine also seems to use more oil, Am i happy not sure, yes ive gained speed under sail, and to be fair it is a sail boat, but ive also lost .5 kt motoring,i to get humming between 1300 -1400 rpm after that it sorts it self out My 3 blader is 21 " , autoprop is 20" have spoken to Brautons they assure me the prop is the right size , maybe ill enqire about a new prop under a different name and see what sizes they offer, regards Carl.

[jose r vigil]

Dear Alan

Thanks for your reply, you letter support me as I feel distressed.
I think you understand what is happening with the concept.

I read all the post dated back to the first and it was very interesting to read the discussion about the basis on how the autopitch might work.

Then I remembered that BRUNTONS probaly filed a patent apllication. The description on operation of this autopitch innovation must be in the overview and claims of the patent flie.

No patenta can be granted without a thoroghful description of the innovation and claims.

Now this is what I have in my mind.

I have a theory of what is happening but as I'm an electronics engineer and not a prop expert I prefer to be fair and continue my research before saying something wrong to the cruisers community

If my theory is right the AUTOPROP will not work in most modern hulls 47 feet and up ( which is the aftermarket boat size market to what this expensive prop is intended to be targeted).

The prop might work in old hulls with saildriives or shaft strut systems not without some vibration. That is probably the reason of some "satisfied" customers.

In the mean time no answer from BRUNTONS , business as usual.

I also researched the flex o fold any customers feedback...Please I need to order a new prop!

Thanks

Jose

Originally Posted by Alan Wheeler

Thanks for your post Jose. Wow, having two props doing the same thing is a little worrying.
It makes me think about a comment I made way back earlier in this thread after seeing the video. And I find my self leaning back toward that original view. I think the issue is more likely one or two blades not deploying properly and placing enormouse load on one side of the shaft causing that wip. Why improper deployment I don't know. But if there are two now with this fault, then I bet there are more out there and I wonder if there is hard work clutching at straws going on in the background at Bruntons, trying to work out an issue.
What I don't get is why the haven't sent a techy guy to any of these boats to take a look. It could be a very simple fault of one blade not having identical pitch to the others. Unless this issue is bigger than we realise and they have checked a thought out like that and found it not the problem. Hmmm, only talking to myself, speculating and causing possible rumours, so I better shut up now.

[jose r vigil]

Hy carl

Thanks for you feedback

waht is you yacht size and make?

I also love the stopping power and we hit 8 knors in reverse. If fact my AUTOPROP only works fine in Reverse.

The vibation at 2800 rpm wich is the slow crusing rpm on my yanmar was so strong we worn the cutlas bearing in two hours of sea trials.

i felt like the shaft can break apart.

Thanks for your feed back

Jose







Th

Originally Posted by CARL

I installed an auto prop in late 2006, the boat deff sails faster she stops better,there is as much prop walk as ever,my cruising speed is slightly down,and i had to fit a shaft brake which hiked up the cost the engine also seems to use more oil, Am i happy not sure, yes ive gained speed under sail, and to be fair it is a sail boat, but ive also lost .5 kt motoring,i to get humming between 1300 -1400 rpm after that it sorts it self out My 3 blader is 21 " , autoprop is 20" have spoken to Brautons they assure me the prop is the right size , maybe ill enqire about a new prop under a different name and see what sizes they offer, regards Carl.

[Alan Wheeler]

The vibation at 2800 rpm wich is the slow crusing rpm on my yanmar was so strong we worn the cutlas bearing in two hours of sea trials.

i felt like the shaft can break apart.

Yikes, that is bad and yes, I believe something will fail. The same goes for the situation of Daves boat. The shaft is bending to such a degree, that something will eventually fail and the bearing must be taking an awefull hammering.
Jose, I can't agree with you thought on the boat size however. I think I understand your comment about the porp suiting 47ft boats and up, but I also think you have in mind that the vibration won't affect boats of this size and up. Well, it is possible that the vibration maynot be able to be felt and maybe the shaft is of such a size that the prop can't bend it, but the unbalanced force is still there and that will be seen on the shaft/bearing surfaces, and translated down the shaft to the coupling and engine mounts. So damage will still be seen in the longer term via early wear.

[CARL]

Jose My boat Luders off shore 47 by Cheoy Lee ,, Perkins 4236 75hp borg warner box approx 2-1 Have since spoken to Bruntons,re slight loss in cruising speed they were very helpfull and i will keep a sea trial data form for next 2 or 3 trips,, with out writing things down i e sea state tide etc it could well be me imagining with out thinking obvious ,like 3-5 kt of tide we regually have in these waters, He did say though if i still was unhappy they would repitch if necessary.

[jose r vigil]

Dear Alan

Thanks for your post.

yes you are right size is not the issue.I didn't explained properly. Sorry

I mentioned 47 footers and up bacuse is the limit on saildrives ( 75 HP engines).

The problem is stronger when your yacht is a shaft and not a saildrive.


But unfortunately my theory is being confirmed

That is the reply for AUTOPROP engineer David.

It is self explanatory, but I can write a new post later as I would like to explain why the AUTOPROP can not work in modern hulls

Thanks and fairwinds


Dear Mr Vigil,
>
> I am sorry that you feel that you are coming up
> against a brick wall. My
> intention in my last email was to help you by
> talking through the
> problem, because I unfortunately, have very little
> information to hand
> to help diagnose the cause of vibration. Furthermore
> I am offended by
> your remarks too, we are only trying to help you and
> to do this I need
> to talk to you or your
> representative/engineer/skipper whoever can help
> me shed some light on this matter. We could have
> sorted this matter out
> weeks ago.
>
> I realized that these situations require a quick
> response. In this case
> we feel that we have let you down and I apologies
> for doing so, however
> I will endeavour to get to the bottom of your
> dilemma with the Autoprop.
>
> So far we have supplied over 7000 Autoprops world-
> wide all working
> satisfactorily. We have supplied about 3 for the
> Hanse 531 and had no
> reports of vibration or performance deficiency for
> this yacht model,
> apart from your installation.
>
> Vibration can be attributed to many things on a boat
> and in our
> experience it is sometimes difficult to pinpoint the
> major contributing
> factor. Shaft alignment, propeller overhang,
> misalignment, straightness
> of the shaft, worn bearing or any other deficiency
> in the drive train or
> with the propeller can lead to vibration. I accept
> that you have made
> some modifications to help improve the shaft support
> but I don't if this
> has help or not. The type of vibration I think you
> may be experiencing,
> could be a related to the load characteristics on
> the propeller. This is
> often made worse by the glass fibre skeg supporting
> the shaft just
> forward of the propeller. The skeg, to some degree,
> will disturb the
> water flow into the propeller. This factor together
> with a propeller
> under high load could be contributing towards your
> vibration levels. The
> fact that your Autoprop it is not vibrating in
> astern confirms that the
> disturbed water flow could be a hindrance. Some
> accurate speed trial
> data would help me confirm if this is a contributing
> factor.
>
> The Autoprops design and function is mostly
> restricted because of the
> feathering aspect of the blade, the same intrinsic
> nature for all
> folding and feathering propellers. The design scope
> is much broader with
> a conventional fixed pitch propeller. For example,
> you can modify blade
> area ratio, pitch distribution and diameter to make
> a propeller work
> better under difficult circumstances. These elements
> are not as pliable
> with feathering and folding propellers mostly
> because of the low blade
> area and sometimes the flat blade shape too.
>
> Sailboat owners have to accept a compromise when
> fitting a feathering or
> folding propeller. Most Autoprop users expect the
> propeller to achieve
> good cruising speeds at lower engine rpm. Speed and
> performance at the
> top end rpm are not of paramount importance to them
> and it is generally
> accepted for a small amount of noise and vibration
> at the top end. Your
> description of the Autoprop installation on your
> yacht seems to be the
> exception rather than the rule.
>
> Ultimately we aim to please all our customers and
> offer the best
> all-round performing propellers. Considering the
> economy values under
> power, good astern thrust and the motorsail ability
> of the Autoprop you
> will realize that the versatility is unsurpassed. We
> try to make all our
> propeller installations work as far as we see
> acceptable. To this end we
> are prepared work on a solution which ultimately
> satisfies you. We
> cannot ultimately guarantee any significant
> reductions in noise and
> vibration even with a modified Autoprop but we are
> willing consider
> replacing your Autoprop with one of our 4 Varifold
> designs. This
> sailboat propellers unique shape when deployed
> enables it to provide
> yachts, even those with very large engines, with the
> low noise and
> vibration characteristics. The Varifold also
> minimised drag under sail.
> Our best recommendation for low noise motoring and
> smooth operation
> would be to go for the 4 blade Varifold. The 4 blade
> has a larger blade
> area which absorbs the power better
>
> Please let me know if you are willing to accept this
> offer.
>
> David Sheppard
>
> Brunton's Propellers Ltd, Oakwood Business Park,
> Stephenson Road,
> Clacton-on-Sea, Essex, CO15 4TL, UK
>
> T: +44 (0) 1255 420 005
> F: +44 (0) 1255 427 775
> Skype: david.sheppard1
> W: www.bruntons-propellers.com
> www.autoprop.com

Originally Posted by Alan Wheeler

Yikes, that is bad and yes, I believe something will fail. The same goes for the situation of Daves boat. The shaft is bending to such a degree, that something will eventually fail and the bearing must be taking an awefull hammering.
Jose, I can't agree with you thought on the boat size however. I think I understand your comment about the porp suiting 47ft boats and up, but I also think you have in mind that the vibration won't affect boats of this size and up. Well, it is possible that the vibration maynot be able to be felt and maybe the shaft is of such a size that the prop can't bend it, but the unbalanced force is still there and that will be seen on the shaft/bearing surfaces, and translated down the shaft to the coupling and engine mounts. So damage will still be seen in the longer term via early wear.

[jose r vigil]

Dear Cruisers

That is my reply to BRUNTONS engineer David

I would like to explain where is the problem but for the ones sufffering AUTOPROP problems I recommend reading Chapter 7 of "the propeller handbook" by Dave Gerr. Good book even for the laymen.

Everything is there.

Anyway I will prepare an explanatory post as soon as I have some time.

In the mean time I have to made my choice of a Gori or a Flex o fold

Any feedback from users?

Thanks!

MY REPLY


David

Thanks for your last e mail. I was reading a book about the subject and I would like to reply only after I was sure of something.

Thanks for your tecnical explanations. That is exactly the same conclusion I have reached after reading the other day the "propeller handbook" by Dave Gerr. A book your US rep should read before saying absurd and misleading things like...... "Oh... you have a whipping problem in your shaft".

How can this guy be so ignorant?. It is a wheeler dealer with no clue of what he is selling.

I have spent about 5000 Euros in the shipyard, the metal shop, the cutlass bearings and in mechanic bills....trying to cure AN INEXISTENT PROBLEM your US rep Geoff told I have to fix to cure the vibration.

WHAT A MESS!

Who is gonna compensate me for that wasted money plus the cost or the AUTOPROP H 6 534 that is now in a box?

I talked with some friends, have got some advice and I have two options

1.- You refund my money in full ( the AB marine bill ) and tell me where to ship the prop, and I will forget the day I meet your US rep at the Miami Boat show.

2.- I will contract a US lawyer and claim the refund and compensation to AB marine your US rep. That is not for money it is just matter of fair play. the one you don't have.

About your offer ,I'm sorry I dont like BRUNTONS and I will not accept a cheaper prop in exchange of the AUTOPROP from you. I can not understand how do you expect that replacing the AUTOPROP for a cheaper propeller can be acceptable after the expense and damage I have suffered.

Let me explain my position BRUNTONS is wrong with its policy. The company is not acting with honesty as you are perfectly aware of the problem some hull shapes generate to your "selfpitch" approach.

Read pages 84 and 85 of Mr gerr " prop hanbook" and tell me if its not evident that the AUTOPROP will never work in straight aperture skegs like the ones in modern fast racers cruisers.

Your AUTOPROP can work in the water tank as shown in your webpage but never without vibration in modern skegs.

That is affecting not only me, but many other of your customers I'm pretty sure, and you can not say that you have 7000 satisfied customers in yatch designs of the 70 's and 80's as " Oh we are very sorry you are the only customer with such a problem".

You do have a big problem...

Be honest and fairplay.

JOSE R VIGIL

Originally Posted by jose r vigil

Dear Alan

Thanks for your post.

yes you are right size is not the issue.I didn't explained properly. Sorry

I mentioned 47 footers and up bacuse is the limit on saildrives ( 75 HP engines).

The problem is stronger when your yacht is a shaft and not a saildrive.


But unfortunately my theory is being confirmed

That is the reply for AUTOPROP engineer David.

It is self explanatory, but I can write a new post later as I would like to explain why the AUTOPROP can not work in modern hulls

Thanks and fairwinds


Dear Mr Vigil,
>
> I am sorry that you feel that you are coming up
> against a brick wall. My
> intention in my last email was to help you by
> talking through the
> problem, because I unfortunately, have very little
> information to hand
> to help diagnose the cause of vibration. Furthermore
> I am offended by
> your remarks too, we are only trying to help you and
> to do this I need
> to talk to you or your
> representative/engineer/skipper whoever can help
> me shed some light on this matter. We could have
> sorted this matter out
> weeks ago.
>
> I realized that these situations require a quick
> response. In this case
> we feel that we have let you down and I apologies
> for doing so, however
> I will endeavour to get to the bottom of your
> dilemma with the Autoprop.
>
> So far we have supplied over 7000 Autoprops world-
> wide all working
> satisfactorily. We have supplied about 3 for the
> Hanse 531 and had no
> reports of vibration or performance deficiency for
> this yacht model,
> apart from your installation.
>
> Vibration can be attributed to many things on a boat
> and in our
> experience it is sometimes difficult to pinpoint the
> major contributing
> factor. Shaft alignment, propeller overhang,
> misalignment, straightness
> of the shaft, worn bearing or any other deficiency
> in the drive train or
> with the propeller can lead to vibration. I accept
> that you have made
> some modifications to help improve the shaft support
> but I don't if this
> has help or not. The type of vibration I think you
> may be experiencing,
> could be a related to the load characteristics on
> the propeller. This is
> often made worse by the glass fibre skeg supporting
> the shaft just
> forward of the propeller. The skeg, to some degree,
> will disturb the
> water flow into the propeller. This factor together
> with a propeller
> under high load could be contributing towards your
> vibration levels. The
> fact that your Autoprop it is not vibrating in
> astern confirms that the
> disturbed water flow could be a hindrance. Some
> accurate speed trial
> data would help me confirm if this is a contributing
> factor.
>
> The Autoprops design and function is mostly
> restricted because of the
> feathering aspect of the blade, the same intrinsic
> nature for all
> folding and feathering propellers. The design scope
> is much broader with
> a conventional fixed pitch propeller. For example,
> you can modify blade
> area ratio, pitch distribution and diameter to make
> a propeller work
> better under difficult circumstances. These elements
> are not as pliable
> with feathering and folding propellers mostly
> because of the low blade
> area and sometimes the flat blade shape too.
>
> Sailboat owners have to accept a compromise when
> fitting a feathering or
> folding propeller. Most Autoprop users expect the
> propeller to achieve
> good cruising speeds at lower engine rpm. Speed and
> performance at the
> top end rpm are not of paramount importance to them
> and it is generally
> accepted for a small amount of noise and vibration
> at the top end. Your
> description of the Autoprop installation on your
> yacht seems to be the
> exception rather than the rule.
>
> Ultimately we aim to please all our customers and
> offer the best
> all-round performing propellers. Considering the
> economy values under
> power, good astern thrust and the motorsail ability
> of the Autoprop you
> will realize that the versatility is unsurpassed. We
> try to make all our
> propeller installations work as far as we see
> acceptable. To this end we
> are prepared work on a solution which ultimately
> satisfies you. We
> cannot ultimately guarantee any significant
> reductions in noise and
> vibration even with a modified Autoprop but we are
> willing consider
> replacing your Autoprop with one of our 4 Varifold
> designs. This
> sailboat propellers unique shape when deployed
> enables it to provide
> yachts, even those with very large engines, with the
> low noise and
> vibration characteristics. The Varifold also
> minimised drag under sail.
> Our best recommendation for low noise motoring and
> smooth operation
> would be to go for the 4 blade Varifold. The 4 blade
> has a larger blade
> area which absorbs the power better
>
> Please let me know if you are willing to accept this
> offer.
>
> David Sheppard
>
> Brunton's Propellers Ltd, Oakwood Business Park,
> Stephenson Road,
> Clacton-on-Sea, Essex, CO15 4TL, UK
>
> T: +44 (0) 1255 420 005
> F: +44 (0) 1255 427 775
> Skype: david.sheppard1
> W: www.bruntons-propellers.com
> www.autoprop.com

[dkall]

Received my replacement Autoprop today. They shipped it directly to me saving me the extra expense of hiring a diver twice plus the time to ship back and wait for the return.

Hope to have it on the boat by this weekend and will let all know the results. I expect it will be much better. The prop is a smaller dia giving me more tip clearance and they flattened the blades a bit so I'll be able to be at a more effecient engine speed. Autoprop tells me I'll loose some effeciency in the prop but the prop doesn't wear out or cost what a new engine, transmission does. Thanks to everyone for the support and advice.

[Alan Wheeler]

Cool. Really look forward to hearing the result.