Vibes and Flexofold props

[w32honu]

I am under the suspicion that folding props can cause a bit of vibration due to moving parts and maybe not the best balance because of that.

Curious if the Flexofold propeller folks (or all folding prop folks) could comment if they have experienced any vibration differences between 2 blades and 3 bladed props.......

Safe to say that the 3 bladed props have less vibration? Safe to say that 3 blades balance better than two?

Boat has a fairly long shaft at 6' 6". Wondering about whip and vibes.

Thanks in advance.

S

[JPA Cate]

We've had both 2 blade and 3 blade folders, on different boats, but not on shafts that long. [Both shafts have run through a strut with a cutlass bearing. No whip.] They don't seem to shimmy or anything like that, the water pressure keeps them closed. The 3 blade (a Flex-o-Fold), is a lot better in reverse than the 2 blade...

Ann

[SimonV]

I am a firm believer in the Kiwi Prop.

[w32honu]

Thanks Ann,

There will definitely be a strut with a cutlass bearing just forward of the prop. But it is still a fairly long shaft. Compensating for the length with an 1 1/4 inch shaft. But still yet....any vibes must be taken into account.

The boat will need a folding or feathering prop. Flexofold looks to be a good option. Maybe a bit less maintenance than feathering models? Definitely a bit less cost.

Sounds like a 3 blade folder would be a better choice for a cruising boat.

S

[pjhagbard]

Hi, I've read virtually all available tests on props and I can say that if you choos flex-o-fold you do the right thing. I have hade different brands and these are by far the best and as Ann T says - 3-blade is far better in reverse. Only reason fot 2-blade is to save a few $... Good luck!

[Wils4x4]

I have 3 blade Flexo-fold, folding props. excellent performance and excellent post sales service.
your vibration could be caused by an anode on the shaft - if you have one?

[David B]

Originally Posted by w32honu

I am under the suspicion that folding props can cause a bit of vibration due to moving parts and maybe not the best balance because of that.

Curious if the Flexofold propeller folks (or all folding prop folks) could comment if they have experienced any vibration differences between 2 blades and 3 bladed props.......

Safe to say that the 3 bladed props have less vibration? Safe to say that 3 blades balance better than two?

Boat has a fairly long shaft at 6' 6". Wondering about whip and vibes.

Thanks in advance.

S

We have a Flexofold three-blade on a saildrive leg. Smooth as silk.

[Suijin]

Originally Posted by w32honu

I am under the suspicion that folding props can cause a bit of vibration due to moving parts and maybe not the best balance because of that.

Curious if the Flexofold propeller folks (or all folding prop folks) could comment if they have experienced any vibration differences between 2 blades and 3 bladed props.......

Safe to say that the 3 bladed props have less vibration? Safe to say that 3 blades balance better than two?

Boat has a fairly long shaft at 6' 6". Wondering about whip and vibes.

Thanks in advance.

S

I'm not sure why you think vibration would be an issue. Folding/feather props are balanced, and the "moving parts" are only moving during transition from closed to open, or feathered forward to feathered for reverse, which is momentary. After that the props are locked.

You could argue that over time wear will lead to looseness, but remember that the number of cycles of opening and closing is pretty low, probably on the order of a few hundred a year even for very active owners.

Maintenance for my MaxProp is pretty minimal. It gets greased every time the boat is hauled (and more frequently if it's more than a year between haul outs), and I've had it apart a few times (you have to disassemble it to take it off) when pulling the shaft to replace the cutlass bearing. And it's tightness and condition are like new.

FYI my prop shaft is almost 6'. You're far more likely to have vibration issues due to a worn cutlass bearing, a misaligned engine, or a poor coupling fit on the shaft.

[meirriba]

Originally Posted by w32honu

I am under the suspicion that folding props can cause a bit of vibration due to moving parts and maybe not the best balance because of that.

Curious if the Flexofold propeller folks (or all folding prop folks) could comment if they have experienced any vibration differences between 2 blades and 3 bladed props.......

Safe to say that the 3 bladed props have less vibration? Safe to say that 3 blades balance better than two?

Boat has a fairly long shaft at 6' 6". Wondering about whip and vibes.

Thanks in advance.

S

No.
2 x Flexofold props on our cat, connected on a seadrive (SD50).

[EWOL Props]

Originally Posted by w32honu

I am under the suspicion that folding props can cause a bit of vibration due to moving parts and maybe not the best balance because of that.

Curious if the Flexofold propeller folks (or all folding prop folks) could comment if they have experienced any vibration differences between 2 blades and 3 bladed props.......

Safe to say that the 3 bladed props have less vibration? Safe to say that 3 blades balance better than two?

Boat has a fairly long shaft at 6' 6". Wondering about whip and vibes.

Thanks in advance.

S

3 blades props have better thrust against wind and sea and give less vibrations than 2 blades one......independently from the brand. The reduced vibration is not a question of balancing, it's an hydraulic effect of the hull's water stream onto the blades

[w32honu]

OK........ thanks for all of the replies.

Its settled. The 3 blade flexofold gets the nod.

[David B]

Good choice - there are other good ones of course, but the reviews of Flexofold are impressive. In our case we did not choose it - just asked for a folding prop (a bit green back then !), but very glad the Flexofold is what came. It's beautifully made, and interestingly, so far we have not needed to think of any antifouling treatment on it (more copper in the alloy?)

[meirriba]

Originally Posted by David B

Good choice - there are other good ones of course, but the reviews of Flexofold are impressive. In our case we did not choose it - just asked for a folding prop (a bit green back then !), but very glad the Flexofold is what came. It's beautifully made, and interestingly, so far we have not needed to think of any antifouling treatment on it (more copper in the alloy?)

This is interesting. Our Flexofold is 6 years old by now. It requires periodical cleaning (every few months - time depends of how much the boat was sailed during the period).

[David B]

No doubt it depends where you are, but for us the Western Med, so far the prop is fine. It of course gets cleaned, but never any more that the hull. The hull is Coppercoat, and just gets a very light coating on it after a year, but I would have thought the separation between hull and prop would be too great to have any effect.

[replusted]

If you do more sailing than motoring, the two blade would be a better choice over the three blade because the two blade prop has less drag.