Autoprop ?

[Yachts66]

Originally Posted by exMaggieDrum

We put good quality electical tape around the circumference of the zinc base on our Maxiprop to help delay the erosion of the zinc at the mounting holes. I was very surprised that this would work. I thought the tape would not stay on (it did but clean the area well first). And I didn't think it would affect the metal as much as it did. It dramatically improved the useful life of the zincs.

I cleaned the zinc with acetone or alcohol first, used 3M 33Super electrical tape, and put it on tight and neat. Just two complete wraps.

Yes, however, doesn't the tape also reduce the effectiveness of the anode, thus failing to give the prop the protection the anode is supposed to give it?

[a64pilot]

I think there is way too much concern about these plastic screws that don't seem to break.
If you don't like them, replace them with SS, they aren't any kind of special thread.
Myself I've ordered the adapter from Islers diving, should put it on this weekend. I did that not because the Autoprop anode doesn't work, it does, just I like the idea of "standard" parts whenever possible.
As far as I can tell so far operation wise my Autoprop is better than any other prop I've been around.
It really shines motor sailing as it will auto pitch up to keep producing thrust when your getting significant speed from the sails. No other prop I know of that is available for small boats will do that.

Anode and plastic screws is such a non problem, if that's all I have to worry about then I don't have a concern.

I have found that my Autoprop is more sensitive to growth reducing performance than a standard fixed three blade is, or it seems to be anyway.

So far the only weakness to this prop I've found is it's cost, it ain't cheap.

[Dockhead]

Originally Posted by a64pilot

I think there is way too much concern about these plastic screws that don't seem to break.
If you don't like them, replace them with SS, they aren't any kind of special thread.
Myself I've ordered the adapter from Islers diving, should put it on this weekend. I did that not because the Autoprop anode doesn't work, it does, just I like the idea of "standard" parts whenever possible.
As far as I can tell so far operation wise my Autoprop is better than any other prop I've been around.
It really shines motor sailing as it will auto pitch up to keep producing thrust when your getting significant speed from the sails. No other prop I know of that is available for small boats will do that.

Anode and plastic screws is such a non problem, if that's all I have to worry about then I don't have a concern.

I have found that my Autoprop is more sensitive to growth reducing performance than a standard fixed three blade is, or it seems to be anyway.

It's been said many times before, but motorsailing with the Autoprop is simply brilliant. You don't even have to change throttle setting as the wind comes and goes -- the prop pitches and repitches constantly to match the load.

This is really important for the way I sail, and probably many other cruisers. Motor sailing is my principle light air sail. I almost never have enough crew to fly a spinnaker or even to carry out sail changes, so I have to make do with white sails. At this latitude, the white sails can't be too big. So I do more motor sailing than straight motoring, which I really only do in a dead calm. With a regular prop, you're just churning up the water motorsailing, when the load is so much different from the standard pure motoring load the prop was designed for.

On the down side, the Autoprop definitely produces more drag than the Maxprop when sailing. I can see the turbulence produce by the prop, behind the boat, while sailing, which is very bad. I would like to see a redesign of this with springs to pull the blades back. It would add complexity, but surely would be worth it.

[Latchdaddy]

Originally Posted by Yachts66

Yes, however, doesn't the tape also reduce the effectiveness of the anode, thus failing to give the prop the protection the anode is supposed to give it?

I agree - the tape acts as an insulator and prevents the anode from doing its job!!.

[Har2015]

Originally Posted by Latchdaddy

I agree - the tape acts as an insulator and prevents the anode from doing its job!!.

Another option that doesn't act as an insulator is using simple fingernail polish along the thinnest part of the anode where it would normally wear away rapidly. Painting a strip of the anode along that area tends to slow the depletion process in that area. At least long enough to get more bang for your buck out of the anode.


Harbor Diving Services, LLC

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[Har2015]

Originally Posted by fstbttms

I disagree with this sentiment. Have you ever broken one of those flimsy POS off in the hole? I have, more than once. Without exception, every single other prop in the world that requires screws to attach an anode uses stainless or monel screws. Why? Because they too are corrosion resistant but unlike the Autoprop screws, are very strong. Like most aspects of Autoprop, the anode attachment screws are a poorly-conceived design for their intended purpose.

I agree with fstbttms, I was actually surprised when introduced to my first autoprop. So much so that I took a picture of it. Haha!

However, sailors, and especially us divers, tend to be mechanically inclined, so simply replace the nylon screws with stainless machine panhead screws. Works like a champ! ::thumbs up::


Harbor Diving Services, LLC

Sent from my iPhone using Cruisers Sailing Forum

[Dockhead]

Originally Posted by HarborDiving

I agree with fstbttms, I was actually surprised when introduced to my first autoprop. So much so that I took a picture of it. Haha! Attachment 105201

However, sailors, and especially us divers, tend to be mechanically inclined, so simply replace the nylon screws with stainless machine panhead screws. Works like a champ! ::thumbs up::


Harbor Diving Services, LLC

Sent from my iPhone using Cruisers Sailing Forum

Yes, but what is depicted in your photo is not failed screws. Those screws are fine.

What is depicted is an anode which wasted around the screw holes and fell off. A different problem.

Sent from my D6633 using Cruisers Sailing Forum mobile app

[fstbttms]

Originally Posted by Latchdaddy

I agree - the tape acts as an insulator and prevents the anode from doing its job!!.

This is simply not the case. While I am not a big fan of the tape solution (for a number of reasons), it is quite effective and seems not to noticeably diminish the anode's ability to protect the prop.

[Polux]

Originally Posted by Dockhead

It's been said many times before, but motorsailing with the Autoprop is simply brilliant. You don't even have to change throttle setting as the wind comes and goes -- the prop pitches and repitches constantly to match the load.

This is really important for the way I sail, and probably many other cruisers. Motor sailing is my principle light air sail. I almost never have enough crew to fly a spinnaker or even to carry out sail changes, so I have to make do with white sails. At this latitude, the white sails can't be too big. So I do more motor sailing than straight motoring, which I really only do in a dead calm. With a regular prop, you're just churning up the water motorsailing, when the load is so much different from the standard pure motoring load the prop was designed for.

On the down side, the Autoprop definitely produces more drag than the Maxprop when sailing. I can see the turbulence produce by the prop, behind the boat, while sailing, which is very bad. I would like to see a redesign of this with springs to pull the blades back. It would add complexity, but surely would be worth it.

I had one for several years and agree with what you say regarding motorsailing. Autoprop has only a minus that can be of no big importance if you have an engine with lots of power for the boat: On dificult circumstances the performance is a lot worse then with other propellers.

I felt that on my previous boat going upwind against steep waves: Not the same power as the previous fixed propeller. Later on a test on a British magazine (Yachting monthly?) I saw that confirmed on a test with many foldable propellers: One of the tests was the pulling force and for that they connected the boat to a dynamometer at the quay and pulled at full engine (always the same boat). The pulling power of the autoprop was just lousy compared with some of the others and if I can remember right, by far the lowest of all.

[Metalcat]

Hi I have a 50'cat with 50hp Yanmar saildrives. Used Autoprop for 3 seasons before the rubber bushing failed requiring a 4 week $1000+ turnaround. When the other one failed the same way the next season I decided not to throw good money after bad and went with Max Props. The autoprops were brilliant performers in most respects (maxprops have better drive into the wind IMO) but I can't personally tolerate the unreliability.

[a64pilot]

Rubber bushing?
Is it internal? I know there are bearings of course and I assume a grease seal, but I didn't know of any bushing?

[aluijten]

Originally Posted by a64pilot

Rubber bushing?
Is it internal? I know there are bearings of course and I assume a grease seal, but I didn't know of any bushing?

Must be the bushing specifically for saildrives. It's required for damping and electrical insulation.

[Metalcat]

Yes it is an internal rubber bushing that is between the hub and the shaft. Both times it looked melted or debonded.

[Har2015]

Originally Posted by Dockhead

Yes, but what is depicted in your photo is not failed screws. Those screws are fine.

What is depicted is an anode which wasted around the screw holes and fell off. A different problem.

Sent from my D6633 using Cruisers Sailing Forum mobile app

Yes - you are correct. My photo wasn't intended to depict worn screws. Sorry for the confusion.


Sent from my iPhone using Cruisers Sailing Forum

[Tessellate]

I know this is an old thread but I'm looking for advice. My Autoprop anode disappeared - popped off, leaving the 3 nylon bolts behind. I dove and removed two (had to use pliers) but the third wouldn't budge and sheared off.
Any way I can get the nylon bolt half out while in the water? Next haul out isn't planned till 9 months from now and the summer cruising season is starting now.
Someone in this thread suggested pounding a sharp screwdriver blade into it. I'm skeptical of that because I wasn't able to pound a screwdriver into one even out of the water. The nylon is hard and only 3/8" wide.
Something like a screw extractor might work but those are intended to have drilled a pilot hole first, and I can't operate a drill underwater.
I have 2 shaft zincs left that are only 20% wasted. But those don't protect the prop because it's brass?