3 blade Max prop vs 3 blade fixed?

[Yeti]

I will also throw my support behind the Max Prop. I love it! Tons of thrust in either direction.

I would also like to share my experience with Max Prop Walk. My boat had the same Max Prop it has now that is had when I bought it. However I have repowered since then. The original engine (Volvo MD2b) had the prop spinning LH turn. The boat walked to starboard pretty hard in reverse. As others have said if you know this is going to happen then just make the adjustments and use to your favor which i did. When I repowered the new engine (M25XPB) had the prop spinning RH turn. The Max Prop can be set up for either way and now I have no noticable prop walk at all.

Same boat, same prop, different engine with different prop settings, no walk.

[TacomaSailor]

Originally Posted by jrbogie

prop walk is the problem when steering in reverse. as i see it anyway. my math says 80% more power in reverse equals 80% more prop walk in reverse resulting in 80% less steering control in reverse. i'm plagued with absolutely no ability to turn my bow to port with the prop producing ANY reverse thrust. feel free to check my math of course. i'm worse at math than i am at point my bow where i want to go in reverse.

Clumsy use of any tool will result in problems and undesirable results!

22-years experience with a 40' / 23,000 pound long-keel boat and another 3-years with a 42' fin keel raceboat both with an 18" Maxprop. That experience tells me that Prop Walk is a huge advantage. I've docked both the boats and picked up moorings in horrible crowded conditions in cross winds and tailwinds from the North end of Vancouver Island to SW mainland Mexico. I'd never want a boat without a Maxprop or similar prop that provides full thrust in reverse.

I've learned:

- Use very little throttle in reverse because it is not needed

- Use short spurts of higher power in reverse to swing the boat without inducing sternward motion

- Use reverse throttle to gain momentum then put the transmission in neutral and steer the boat with it's momentum

- plan all your maneuvers to take advantage of Prop Walk

- Practise, Practise, Practise! I used to go out into open water and throw a life ring in. Then I'd spend hours backing up to the life ring from all wind and current angles. I learned how the boat and prop worked together in a wide variety of conditions.

- I learned I can easily back in a perfectly straight line at 6 knots and with a firm grip on the wheel I could precisely steer anywhere I wanted.

[jrbogie]

Originally Posted by TacomaSailor

Clumsy use of any tool will result in problems and undesirable results!

22-years experience with a 40' / 23,000 pound long-keel boat and another 3-years with a 42' fin keel raceboat both with an 18" Maxprop. That experience tells me that Prop Walk is a huge advantage. I've docked both the boats and picked up moorings in horrible crowded conditions in cross winds and tailwinds from the North end of Vancouver Island to SW mainland Mexico. I'd never want a boat without a Maxprop or similar prop that provides full thrust in reverse.

I've learned:

- Use very little throttle in reverse because it is not needed

- Use short spurts of higher power in reverse to swing the boat without inducing sternward motion

- Use reverse throttle to gain momentum then put the transmission in neutral and steer the boat with it's momentum

- plan all your maneuvers to take advantage of Prop Walk

- Practise, Practise, Practise! I used to go out into open water and throw a life ring in. Then I'd spend hours backing up to the life ring from all wind and current angles. I learned how the boat and prop worked together in a wide variety of conditions.

- I learned I can easily back in a perfectly straight line at 6 knots and with a firm grip on the wheel I could precisely steer anywhere I wanted.

uh, ahem. your reverse technique is exactly the same as mine. you missed the point entirely as is evident with your statement, "plan your maneuvers to take ADVANTAGE of prop walk." explain to me, if you can, how you take advantage of prop walk when maneuvering the bow to port in reverse?

you've about half my experience in large keel boats, btw, but both our statements of prowess don't matter a lick do they?

[Cheechako]

I doubt the 80% figure, but I love Maxprops. What a great find. They do help very much in reverse for sure. I could stop my heavy 47 footer in one boat length from 5+ knots with a Maxprop. Don't ask how I found out!

[TacomaSailor]

"you've about half my experience in large keel boats, btw, but both our statements of prowess don't matter a lick do they?"

Then I have trouble understanding your problem backing with a Maxprop.

There are a few situations where a strong Prop Walk is not an advantage but careful planning and control of the boat's momentum will eliminate almost any negative impact of the Prop Walk.

My reason for listing my experience is not to wave my weenie, but to clarify the wide variety of backing experiences I've had with a Maxprop. I would be hard pressed to imagine a backing situation I've not experienced during the last 45-years of sailing hundreds of different boats on the US east and west coast. And, I've seen almost all of them in the various Maxprop boat's I've operated. One of those was 65-feet and 85,000 pounds.

My experience is that a Maxprop can be easily managed.

[Davidhoy]

Originally Posted by skipgundlach

Two things:

First, reconditioning can be very expensive, but it's worth it.

Second is that the shaft has to be cut appropriately; standard props have too much thread out (and may not be able to go back on because of not enough).

As to pitch, amen to that. David, I have a sistership and can give you our specs. skipgundlach@gmail.com far preferred for contact. The size of the prop will determine the right pitch; I'm assuming you have the original engine and tranny setup?

As to backing down, yes, indeed. All the thrust you would have had in forward.

As to backing, email me.

We sold our 3-blade spare which came with the boat; even if it meant replacement, we'd use the maxprop.

Hi Skip,

I've heard of you and your boat! Sorry about your misadventures a few years back, very happy to know that they were but a temporary setback :-)

My Morgan has been repowered with a Westerbeke 82B that generates 82hp at 3600 RPM, along with a ZF 25 transmission. The PO owned the boat a little over two years, and in that time replaced the Max prop, but left it behind as a spare. According to his pre-purchase survey, which gave me a copy of, the surveyor wrote this:

(1) “Max Prop”, 22” (diameter) x unknown (pitch), (3) blade, bronze

The propeller blades were checked for proper tracking and found to be within acceptable limits.

However, in addition to significant blade edge gouges, the “propeller blade rotating angle gears” displayed significant “play” (wear) when the blades were moved through their “forward” to a “reverse” angle.

It is recommended that the propeller be reconditioned by a Max Prop service provider.

I've emailed the PO to get some details on the reasons and thinking behind replacing it. Hopefully no significant modifications were made to the shaft that would make reinstalling the Max a bigger job than necessary.

I'll email you too, Skip. I'd love to get your thoughts on how best to set up a Morgan 462 for extended cruising. You've been there and done that, so your advice would be most welcome. That, and of course, how to handle the boat in reverse ;-)

Regards,
David

[Cheechako]

Originally Posted by TacomaSailor

"you've about half my experience in large keel boats, btw, but both our statements of prowess don't matter a lick do they?"

Then I have trouble understanding your problem backing with a Maxprop.

There are a few situations where a strong Prop Walk is not an advantage but careful planning and control of the boat's momentum will eliminate almost any negative impact of the Prop Walk.

My reason for listing my experience is not to wave my weenie, but to clarify the wide variety of backing experiences I've had with a Maxprop. I would be hard pressed to imagine a backing situation I've not experienced during the last 45-years of sailing hundreds of different boats on the US east and west coast. And, I've seen almost all of them in the various Maxprop boat's I've operated. One of those was 65-feet and 85,000 pounds.

My experience is that a Maxprop can be easily managed.

I agree, while there are particular situations where it is hard to use prop walk to advantage, thinking ahead helps get rid of that problem. At any rate, trying to reverse, "prop walk" is over rated as a detriment, if you don't gun your engine and creep up on getting some speed, prop walk will not occur.

[barnakiel]

You send it to a good garage and the re-machine the thing. Then you sail faster withe Max prop.

Talk to any big yacht yard - they will know where you nearest place is that can handle this.

b.

[JPA Cate]

Originally Posted by Davidhoy

Thanks, Ann! Very good point, one I'm working on already. Just trying not to embarrass myself too much in the process ;-)


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You've a good attitude, mate. Get hold of 4 large wine bladders, some string, and four rocks. Go out where there is some clear water, lay out your markers, and experiment. I have a feeling, based on what Tacoma Sailor wrote, that you don't get your boat running fast enough in reverse to have enough water flow over the rudder to steer her effectively. Sometimes, you have to simply get the boat moving. But, go play, and your skills will improve as you learn what to anticipate that she will do. No one is born knowing this stuff.

Good luck and speedy learning to you.

A.

[JOHNMARDALL]

Originally Posted by jrbogie

prop walk is the problem when steering in reverse. as i see it anyway. my math says 80% more power in reverse equals 80% more prop walk in reverse resulting in 80% less steering control in reverse. i'm plagued with absolutely no ability to turn my bow to port with the prop producing ANY reverse thrust. feel free to check my math of course. i'm worse at math than i am at point my bow where i want to go in reverse.

Two words - bow thruster.
John Mardall
Vetus Maxwell Group

[Davidhoy]

Originally Posted by JOHNMARDALL

Two words - bow thruster.

John Mardall

Vetus Maxwell Group

Got one. And it's a Vetus! PO installed it new last year, but temporarily inoperative due to lightning strike.

So, John, any idea where I can get parts for an old Vetus Alexander II windlass? Are you the John that the guys at Sailorman in Fort Lauderdale were telling me about?

Regards,
David.




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[JOHNMARDALL]

Max Props are great, for all the reasons mentioned, but sending one to a machine shop is asking for trouble. Bite the bullet and send it back to PYI, they're not cheap but they really know what they're doing. They will also recommend a pitch setting.
The rudder only works when there's enough water flowing over it, so you may still need a bow thruster for good docking control, but you won't regret getting the Max Prop working properly
Good luck
John Mardall
Vetus Maxwell Group

[JOHNMARDALL]

Guilty as charged - I'm that John. We probably still have some parts for the venerable Alex, either in the Maryland warehouse or at headquarters in Holland. Let me have a list of what you need or tell me if you need a parts list and I'll email one to you, and then forward your list to the right person.
Oh - if you don't have a manual and parts list for your thruster, give me the model (on the gray plastic solenoid cover)and I'll also send those.
Thanks for your preservation efforts
John Mardall
Vetus Maxwell Group

[Davidhoy]

Originally Posted by JOHNMARDALL

Guilty as charged - I'm that John. We probably still have some parts for the venerable Alex, either in the Maryland warehouse or at headquarters in Holland. Let me have a list of what you need or tell me if you need a parts list and I'll email one to you, and then forward your list to the right person.
Oh - if you don't have a manual and parts list for your thruster, give me the model (on the gray plastic solenoid cover)and I'll also send those.
Thanks for your preservation efforts
John Mardall
Vetus Maxwell Group

Pleased to meet you, John, even if only virtually ;-). Apparently I just missed you at the store a couple of weeks ago.

I'm looking for the gypsy-side clutch nut. The old one literally fell apart during the pre-purchase survey. I'm probably going to replace the entire unit in the next year or two, but since I need to pay for the lightning damages to my boat first, the windlass replacement will need to wait a little while.

Thanks,
David


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[J Clark H356]

I just got my 2003 MaxProp back from PYI reconditioning and will install this week. Cost was $731 to recondition plus shipping. I got new hub, cone gear, reconditioned blades and whatever else they recommended. After discussion with them, we also had them change the pitch from 22 to 20. That will give me 300 more RPM and I will be at my full rated 3600 versus 3400 RPM from my original 2003 installation. I have 1271 hours on the engine and 7620 NM. Although my fuel economy was good before, I think this will improve speed at same cruise setting and reduce fuel use some.

I can back my boat very well and really like the MaxProp.

Jerome from PYI was excellent to work with.

I'm looking forward to this coming weekend to see what happens.


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