Folding Prop Report

[Solstice]

Maine,
Looking forward to your experience as I am now on season 4 of indecision I have narrowed my list down to MP, Gori or Variprofile--The only reason the Gori remains in the mix is it the only featherer and this would be an advantage in our lobster pot invested waters.
However my main criteria is prop walk. I know I am in the minority as I fall in the 'Prop Walk should be tolerated' vs 'PW is your friend' camp. I've learned how to use it over 25 years of slipping my boat, but my boat has horrible PW and my slip is oriented with a wicked current and tide set the wrong way!
Used an Autoprop for 15 years and loved that thing (never any thrown blades) but alas it does not fit my partial skeg arrangement...

 

[Maine Sail]

Sorry for the delay in updating this. So far the J-Prop has been an absolute dream so far.

Reverse is simply amazing and forward is as good as the Campbell Sailor. The J-Prop is also 99.7% as smooth as the Campbell Sailor was! This is amazing because the blade centers are indeed further aft. I did adjust the pitch once and it took me less than 20 seconds to do so with nothing more than a diving mask on. One happy camper..!

 

[Solstice]

Thanks for the update Maine. I've been looking forward to your report as I really need to make a decision. A couple of questions--
--I assume you have found the pitch that lets you get the boat up to rated max rpm? I've found that with feathering/folding props, no matter how much you adjust pitch, it is still tough to not be overpitched due to the nature of the prop. Even my old Autoprop would be off by about 400 rpm.
--I have a skeg with no room for a shaft zinc. Some manufacturers like Gori use a larger zinc setup for this situation. I currently use a prop nut zinc (sucks) and want to make sure I can properly zinc the prop/shaft.
--Could you comment a bit more on reverse? I'm well versed on using prop walk, but my slip arrangement makes it a PITA and I want to remove as much PW as possible.

As always thanks for reporting from the field!!

 

[Maine Sail]

Thanks for the update Maine. I've been looking forward to your report as I really need to make a decision. A couple of questions--
--I assume you have found the pitch that lets you get the boat up to rated max rpm?

With the J-Prop it is easy to not be over pitched and pitch adjustment takes seconds.. I am actually purposely slightly under pitched but have it adjusted to account for the alternator and the engine driven refrigeration something most prop shops don't or won't account for. I will likely bump the alternator up later this summer to closer to 200A and will see if it needs further adjustment. When my alt is running it is always at full bore so this and refrigeration needed to be accounted for in load.

I've found that with feathering/folding props, no matter how much you adjust pitch, it is still tough to not be overpitched due to the nature of the prop. Even my old Autoprop would be off by about 400 rpm.

Again many prop shops size incorrectly and with a folder you are stuck with what you get. With a Max or Vari or J-Prop etc. it is easy to adjust so you are not over pitched but "easy" is a relative thing as most Max props need a haul out for adjustment. I don't consider the Auto Prop an adjustable pitch prop and in fact have never been on a boat with an AutoProp where they engine could turn up to factory specified recommended max RPM. With the J-Prop I simply throw on a mask, jump in, pull the cone, move it one click and release the cone. Pitch adjustment done..

--I have a skeg with no room for a shaft zinc. Some manufacturers like Gori use a larger zinc setup for this situation. I currently use a prop nut zinc (sucks) and want to make sure I can properly zinc the prop/shaft.

Probably the smartest course of action is a thin-line zinc like Beneteau uses. You should, by proper design, have a minimum of one shaft diameters length between the end of the strut and your prop.

--Could you comment a bit more on reverse? I'm well versed on using prop walk, but my slip arrangement makes it a PITA and I want to remove as much PW as possible.

As always thanks for reporting from the field!!

There is still prop walk. It is less than the Campbell however but I can still "use it" to my advantage so it is still there. I've never known of any prop on a sailboat that can eliminate prop walk...

For me the biggest advantage of the J-Prop is the in-water 20 second pitch adjustment and it has been silky smooth.. Considering I have already tweaked it twice that is $800.00 on short hauls I've saved...

 

[Solstice]

With the J-Prop it is easy to not be over pitched and pitch adjustment takes seconds.. I am actually purposely slightly under pitched but have it adjusted to account for the alternator and the engine driven refrigeration something most prop shops don't or won't account for. I will likely bump the alternator up later this summer to closer to 200A and will see if it needs further adjustment. When my alt is running it is always at full bore so this and refrigeration needed to be accounted for in load.



Again many prop shops size incorrectly and with a folder you are stuck with what you get. With a Max or Vari or J-Prop etc. it is easy to adjust so you are not over pitched but "easy" is a relative thing as most Max props need a haul out for adjustment. I don't consider the Auto Prop an adjustable pitch prop and in fact have never been on a boat with an AutoProp where they engine could turn up to factory specified recommended max RPM. With the J-Prop I simply throw on a mask, jump in, pull the cone, move it one click and release the cone. Pitch adjustment done..




Probably the smartest course of action is a thin-line zinc like Beneteau uses. You should, by proper design, have a minimum of one shaft diameters length between the end of the strut and your prop.




There is still prop walk. It is less than the Campbell however but I can still "use it" to my advantage so it is still there. I've never known of any prop on a sailboat that can eliminate prop walk...

For me the biggest advantage of the J-Prop is the in-water 20 second pitch adjustment and it has been silky smooth.. Considering I have already tweaked it twice that is $800.00 on short hauls I've saved...

Thanks Maine,
Certainly agree that one cannot eliminate PW, just take advantage of the advantage of blades changing their orientation to minimize extreme PW, which I currently have.

The '5' series boats use a water scoop in the skeg to feed sufficient water into the cutless and their is the proper 1.5" clearance (1" SS shaft) and I do have some of the Bene thin zincs, however this question was posed to G. Douglas and he recommended against using them :cry:

 

[Maine Sail]

Thanks Maine,
Certainly agree that one cannot eliminate PW, just take advantage of the advantage of blades changing their orientation to minimize extreme PW, which I currently have.

The '5' series boats use a water scoop in the skeg to feed sufficient water into the cutless and their is the proper 1.5" clearance (1" SS shaft) and I do have some of the Bene thin zincs, however this question was posed to G. Douglas and he recommended against using them :cry:

Why?

 

[IStream]

Maine, I'm wondering if your original folder was unbalanced, either due to blade weight, pitch, or excursion angle.

 

[Maine Sail]

Maine, I'm wondering if your original folder was unbalanced, either due to blade weight, pitch, or excursion angle.

Had it computer balance checked (Prop Scan). As the owner of the shop said. "It is about as good as it will get, but its still a two blade prop."......

 

[Alan Gomes]

How much did the J-prop set you back, if you don't mind my asking?

 

[Maine Sail]

How much did the J-prop set you back, if you don't mind my asking?

It is right in-line with all the other about $3200.00 or approx 1k per blade......

 

[Alan Gomes]

It is right in-line with all the other about $3200.00 or approx 1k per blade......

Thanks. I thought it might be something along those lines.

I'm hoping to upgrade at some point to a Campbell Sailer, which is of course a good deal less money for a given diameter. Hopefully they can get the pitch correct from the start so I don't have to incur the expense of an additional short haul. With my little 1GM (not even a 1GM10!) I need the prop to be as efficient as possible. My current 3 blade fixed prop pushes my 5200# boat surprisingly well, but I'm hoping to reduce the drag of those Dumbo-eared blades on what I presume is a standard Michigan Wheel prop. The gentleman I wrote to at West by North (Kelsey) claims that my performance under power will *increase* with his prop. But if I can just maintain the good motoring performance I have now but pick up speed under sail I'd be a happy camper.

Anyway, glad you are pleased with your new acquisition. It sounds like a sweet piece of hardware.

 

[gettinthere]

Mainsail
Is there a loss of efficiency with your new prop vs a fixed blade prop?

My max prop seems to be costing me about a half knot and pyi agreed.

 

[seadaddler]

Pitch

I think the proper pitch is everything and most important thing for sure and when my 2007 H-36 was brand new the dealer installed prop was the wrong pitch and lacked motoring and would not reach max rpm's.
After many talks with Flex O Fold they suggested the pitch for my boat and it was right on the money and I have been very happy over the years.
I get great comments how smooth and great performance when new crew comes aboard,I think the price is much better than most other props and very well built and does not need any greasing or any maintenance other than keeping barnacles off the blades and yes I have the 3 blade model.
Every few years when I haul for bottom paint I give it a good cleaning and looks like new again and never have had any problems at all,the price and other reviews from other sailors is why a decided to go with it.
Nick

 

[Maine Sail]

Mainsail
Is there a loss of efficiency with your new prop vs a fixed blade prop?

My max prop seems to be costing me about a half knot and pyi agreed.

None that I can accurately determine but the blades are significantly larger in surface area than the Campbell. I suspect this helps make up for the flat blade shape. I think if you compared blade surface area to blade surface area you'd find the Campbell is a much more efficient foil shape but because they can't rotate / feather they need to have less surface area for drag..

 

[Maine Sail]

I think the proper pitch is everything and most important thing for sure and when my 2007 H-36 was brand new the dealer installed prop was the wrong pitch and lacked motoring and would not reach max rpm's.
After many talks with Flex O Fold they suggested the pitch for my boat and it was right on the money and I have been very happy over the years.
I get great comments how smooth and great performance when new crew comes aboard,I think the price is much better than most other props and very well built and does not need any greasing or any maintenance other than keeping barnacles off the blades and yes I have the 3 blade model.
Every few years when I haul for bottom paint I give it a good cleaning and looks like new again and never have had any problems at all,the price and other reviews from other sailors is why a decided to go with it.
Nick

Proper pitch is everything and Flex-O-Fold got ours spot on where Campbell failed to do so. In reality our Campbell cost nearly as much as the two blade FOF when you added in the extra short haul for pitch adjustment. I should have gone with a three blade FOF initially but after the vibration issues with the two blade and how far behind the bearing the blades are I continued to search..

 

[fstbttms]

...most Max props need a haul out for adjustment.

Not so. ANY Max Prop model can have its pitch adjusted while the boat stays in the water and PYI will confirm this.

 

[Maine Sail]

Not so. ANY Max Prop model can have its pitch adjusted while the boat stays in the water and PYI will confirm this.

Yes absolutely IF you live in an area with a diver willing to do so.... When you get to an area like Maine these guys are slim to non existent especially with the 6" visibility we often have..

 

[Solstice]

Why?

I suspect for sufficient water flow. GD posted his recommendation against on the 355 message board without saying why. I will ask though.

BTW this was taken after having the prop balanced up at Accu Tech with using Prop scan (I suspect the same as yours) and they offered to apply the Velox prop paint. I can only say it was a miserable fail--and not cheap!

 

[gettinthere]

None that I can accurately determine but the blades are significantly larger in surface area than the Campbell. I suspect this helps make up for the flat blade shape. I think if you compared blade surface area to blade surface area you'd find the Campbell is a much more efficient foil shape but because they can't rotate / feather they need to have less surface area for drag..

You are comparing 2 folding props, right?

My question was folding vs fixed. PYI admits their maxprop is less efficient than a similar fixed blade prop. We figure by a half knot at cruise

 

[JensJaunt]

Proper pitch is everything and Flex-O-Fold got ours spot on where Campbell failed to do so. In reality our Campbell cost nearly as much as the two blade FOF when you added in the extra short haul for pitch adjustment. I should have gone with a three blade FOF initially but after the vibration issues with the two blade and how far behind the bearing the blades are I continued to search..

I put A Campbell sailor prop on my CS36 about 4 months ago, it had a Martec 2 blade folding prop. The vibration is gone and now I have some control in reverse but bad prop walk. I have been seriously thinking about trying the Kiwi prop, did you consider that one?