Folding vs Feathering Prop - views requested - Page 2 - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > On Board > Gear & Maintenance
 Not a Member? 
  #11  
Old 01-07-2010
PCP's Avatar
PCP PCP is offline
Senior Member
 
Join Date: Dec 2004
Location: Portugal, West Coast
Posts: 16,160
Thanks: 21
Thanked 95 Times in 79 Posts
Rep Power: 10
PCP will become famous soon enough
Quote:
Originally Posted by dantaden View Post
Thanks for your experience. I'd like to keep discussion open for more advise on these and other models.


Autoprop - always been curious about this prop. Can you advise your experience with fwd/reverse prop walk and if you found the blades move and noisey under sail. As well, any trouble with blades not opening under fwd/rev. And as above your sales & service experience, how was it ?
Very little prop walk, the efficiency is the same, backwards or forward, you don't hear nothing and no problem at all. I had never need any exterior service. the maintenance is very simple and I have done it myself (5 minutes).

This is not just a folding propeller, but an automatically adjustable pinch propeller. Itīs biggest advantage it's the cut on fuel consumption and the increased autonomy.

It is especially efficient while motorsailing. Suppose I have wind to make 3.5 knots and I want to make 6 knots. With the standard propeller I would have to put the motor at 2000rpm. With an Autoprop, to do the same, I only need 1000rpm. There is almost no noise and the autonomy increases almost twice, not to mention costs and motor life. The only problem is that when the wind picks up and you donít need that extra push to sail at more than 6K, sometimes you forget to turn the engine of, because you cannot hear it.

It is also very efficient if you have flat seas, or just small waves. In those conditions I could make the same speed with less 800rpm, comparing with the standard propeller.

Minus:

Price

In stormy or very agitated seas probably this propeller is marginaly less efficient than the standard one. On those rare conditions were the speed of the boat varies constantly because big waves are stooping the boat I believe that there is some loss in efficiency (because the pinch is changing all the time), but I am not sure.

The other only propeller I would consider to replace an Autoprop would be a Gori with and overdrive. They were also impressive on that test that I had mentioned.

Regards

Paulo
Reply With Quote Share with Facebook
  #12  
Old 01-07-2010
Great Lakes Sailor
 
Join Date: Jul 2001
Location: Saginaw, MI
Posts: 184
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 14
padean is on a distinguished road
VariProp

Got a Variprop for my CS34 last year to improve the sailing performance and help with a little local racing. I have been very impressed with this prop.

Pros:
  1. Easy to install
  2. Very easy to adjust pitch, both forward and reverse
  3. Excellent power in reverse, better than my old 2-blade fixed with less propwalk
  4. Good power through rough seas (3-blade model)
Cons:
  1. Expensive (consistent with other feathering props)
  2. Defective screws detected by manufacturer, but they changed out the entire prop-head for a new one at no cost - even offered to pay the haul-out fee
  3. Not quite as efficient as a fixed prop
I went with feathering over folding because I have to reverse our of a slip in a narrow channel. Folding definitely has lower drag, but not as much thrust effeciency.
__________________
PDean
CS 34
Saginaw Bay, Michigan
"The pessimist complains about the wind; the optimist expects it to change; the realist adjusts the sails." - William Arthur Ward
Reply With Quote Share with Facebook
  #13  
Old 01-07-2010
christyleigh's Avatar
Senior Member
 
Join Date: Dec 2001
Location: North Brookfield, Mass.
Posts: 935
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 13
christyleigh is on a distinguished road
Quote:
Originally Posted by PCP View Post
In stormy or very agitated seas probably this propeller is marginaly less efficient than the standard one. On those rare conditions were the speed of the boat varies constantly because big waves are stooping the boat I believe that there is some loss in efficiency (because the pinch is changing all the time), but I am not sure.
My understanding of what is going on and why differs with that assumption of "less effciency". The "Auto" in AutoProp gives a fantastic Bite when needed and 'de-pitches' when not.... such as when you have sail up to aid in propelling the boat by its unique design. So I carry that forward to assume that when "big waves are stopping the boat" it goes to max pitch and bites hard - just like when you are starting from a stop - in either direction (the blades switch around to always face the same way into the resisting water). I have had AutoProps on 2 different boats and although I can't claim any perfectly scientific A to B tests if price is not an issue AutoProp has done all it claims to do for me.
__________________
Stan
'Christy Leigh'
NC 331
Wickford/Narragansett Bay RI
Reply With Quote Share with Facebook
  #14  
Old 01-07-2010
tommays's Avatar
Senior Member
 
Join Date: Sep 2008
Posts: 4,232
Thanks: 1
Thanked 24 Times in 24 Posts
Rep Power: 6
tommays will become famous soon enough
In this neck of the woods the folders even when geared require a LOT of sea life maintenance OR they tend to stay closed partially
__________________
1970 Cal 29 Sea Fever

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

1981 J24 Tangent 2930
Tommays
Northport NY


If a dirty bottom slows you down what do you think it does to your boat
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
  #15  
Old 01-07-2010
RichH's Avatar
Senior Member
 
Join Date: Jul 2000
Location: Pennsylvania
Posts: 2,762
Thanks: 9
Thanked 64 Times in 57 Posts
Rep Power: 15
RichH will become famous soon enough
Most of the feathering props are 'pitch adjustable' .... some can either have their pitch adjusted while the prop is still installed and the boat is IN the water. With most feathering props, you can OPTIMIZE the prop's pitch to optimized engine rpm for best power/efficiency,etc.

Folders while having much better drag characteristics, cant be easily pitch adjusted.
Reply With Quote Share with Facebook
  #16  
Old 01-07-2010
jrd22's Avatar
Courtney the Dancer
 
Join Date: Nov 2000
Location: San Juan Islands., WA, USA
Posts: 3,813
Thanks: 3
Thanked 14 Times in 14 Posts
Rep Power: 14
jrd22 will become famous soon enough
We had an Autoprop on our Northsea 34 for 15 years and never had a problem with it. No prop walk and lot's of thrust in forward and reverse made close quarters maneuvers easy. You do need to use more throttle from a stop compared to a fixed blade, but you get used to it. Our sailing speed in light winds increased at least 1/2 knot compared to the three blade fixed and our motoring speed increased almost 3/4 knot at the same rpm so we reduced the rpm to cut down on engine noise and still maintained a higher speed. The only contact with the dealer was to order the little zincs, which we received promptly. Wish I could afford one for the current boat.
__________________
John
SV Laurie Anne

1988 Brewer 40 Pilothouse

Reply With Quote Share with Facebook
  #17  
Old 01-07-2010
PCP's Avatar
PCP PCP is offline
Senior Member
 
Join Date: Dec 2004
Location: Portugal, West Coast
Posts: 16,160
Thanks: 21
Thanked 95 Times in 79 Posts
Rep Power: 10
PCP will become famous soon enough
Quote:
Originally Posted by christyleigh View Post
My understanding of what is going on and why differs with that assumption of "less effciency". The "Auto" in AutoProp gives a fantastic Bite when needed and 'de-pitches' when not.... such as when you have sail up to aid in propelling the boat by its unique design. So I carry that forward to assume that when "big waves are stopping the boat" it goes to max pitch and bites hard - just like when you are starting from a stop - in either direction (the blades switch around to always face the same way into the resisting water)..
No, the specific situation that I was talking about happened at Fournells in Mallorca. Furnells is a large cove with a small entrance. It is a very good shelter. Me and lot's of boats were inside while the Mistral was blowing outside at more than 40 k. It take almost a week for the wind to lower to about 25K. The seas raised by that storm were hudge (for the med) with very steep 5 or 6 meters waves that come (as usual in the med) with a very short period.

The wind was just blowing dead on the passage and we atempted to sail out knowing that if he could motor out of that narrow passage we could turn the boat and sail fast out of that hole.

Everything went find except that we take 3/4 of an hour to clear that small passage, making less than a knot with the engine at 3/4 of max Rpm.

The boat took a steep big wave and the autoproop ajusted for power, the boat went down the same wave and the propeller adjusted for speed. Almost imediately it started to climb another one and the propeller tried to ajust for bite, but with so much fast changes in pitch, de overall bite was not good.

As jrd22 as said: "You do need to use more throttle from a stop compared to a fixed blade" and as the boat was always trying to gain speed, just to be stoped by the next have, I believe that in these conditions a fixed prop woud have been more efficient.
Reply With Quote Share with Facebook
  #18  
Old 01-07-2010
Valiente's Avatar
Senior Member
 
Join Date: Jun 2006
Location: Toronto
Posts: 5,491
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 10
Valiente has a spectacular aura about Valiente has a spectacular aura about
Quote:
Originally Posted by RichH View Post
Most of the feathering props are 'pitch adjustable' .... some can either have their pitch adjusted while the prop is still installed and the boat is IN the water. With most feathering props, you can OPTIMIZE the prop's pitch to optimized engine rpm for best power/efficiency,etc.

Folders while having much better drag characteristics, cant be easily pitch adjusted.
This is precisely why I chose a four-blade feathering VariProp for the steel cruiser (I want a far more torque-y bite in reverse) and a Gori folder for the racer.

I have yet to install the VariProp as I am repowering this year, but the Gori's been on a number of seasons and you can read my positive remarks (and a few reservations) using "Valiente" and "Gori" in the search function.
__________________
Can't sleep? Read my countdown to voyaging blog @
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
  #19  
Old 01-08-2010
christyleigh's Avatar
Senior Member
 
Join Date: Dec 2001
Location: North Brookfield, Mass.
Posts: 935
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 13
christyleigh is on a distinguished road
Quote:
Originally Posted by PCP View Post
The boat took a steep big wave and the autoproop ajusted for power, the boat went down the same wave and the propeller adjusted for speed. Almost imediately it started to climb another one and the propeller tried to ajust for bite, but with so much fast changes in pitch, de overall bite was not good.

As jrd22 as said: "You do need to use more throttle from a stop compared to a fixed blade" and as the boat was always trying to gain speed, just to be stoped by the next have, I believe that in these conditions a fixed prop woud have been more efficient.
Thinking overnight I may have the auto-pitch adjustment bass ackwards in my head but I have never been without all the power I needed. The waves you are speaking of are 2-3 times more than I have ever seen..... and I plan to keep it that way. The only 'test' I have ever given my AutoProp was straight into a 20kt wind with an opposing tide in L.I Sound creating very steep, short period 5-6 footers (not meters ). There was salt water raining from the rigging but I was holding 5-6kts easily with only a slight increase in throttle. Maybe unlike your experience my Auto was always in Power mode and never coasting down your much higher waves so it just kept pulling like a tractor ignoring the waves completely.
__________________
Stan
'Christy Leigh'
NC 331
Wickford/Narragansett Bay RI
Reply With Quote Share with Facebook
  #20  
Old 01-08-2010
October Moon B43
 
Join Date: Mar 2009
Location: SE Pennsylvania
Posts: 400
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 6
MJBrown is on a distinguished road
Had an Autoprop on a 36'er and loved it. The pitch was perfect from the beginning but the boat did prop walk something terrible but I'm not sure if it was the boat or the prop. I got used to it and used to my advantage when approaching or leaving docks. Picked up apx 3/4 kt of speed under sail alone and suspect an equal amount under power. Always drove the boat consistently strong. The worst conditions were 30kts on the nose, 5-6' chop for 6hrs and never a problem. You do need to make sure you grease the hubs when you haul the boat for painting, etc. Otherwise a blade can hang up and cause vibration at low speeds. The only real issue was longevity. Seems the prop we had experienced some corrosion to some internal portion of the bearing race. As it was not a replaceable part it's expected that prop at some time will have to be replaced. Not sure if this was an issue with this particular prop or not. Traded the boat so will never know.
Reply With Quote Share with Facebook
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Folding vs. Feathering Prop? MJKahn Hunter 4 08-06-2007 09:54 AM
Hydralign Feathering Prop BELLATRIX1965 Gear & Maintenance 2 01-01-2007 09:25 PM
Zincs for Sail Prop feathering prop jrbarn Gear & Maintenance 4 09-20-2006 10:40 AM
Choosing the Right Propeller Sue & Larry Gear and Maintenance Articles 0 02-04-2003 07:00 PM
Feathering and folding props FredSprigman Gear & Maintenance 3 09-08-2001 06:21 PM


All times are GMT -4. The time now is 11:41 PM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.