Maxprop - making it feather

[[2574]]

First sail this weekend with the new Maxprop. Yes it does what it says on the tin - a noticeable improvement in speed in light airs. We're sailing in winds this year that last year would have seen us starting the engine. Whether there's a big improvement in stronger wind performance is more difficult to say - we had gusts of 34 knots at the weekend and we were going like hell - but then we would have been last year as well!

I have noticed a reduction in ahead acceleration speed - the prop is slightly lower geared than the fixed and I think it might stand a slightly coarser setting. Top speed is about the same. Astern performance is a revelation, bags more thrust and control, hugely better.

Question - how do you make it feather? I've found that stopping the engine in ahead is not enough - I have to put gearbox astern (with engine stopped), it then feather's and then I can put gearbox in neutral. No jamming of the gearbox in astern as was happening last year with the three blade fixed prop.

Any views?

 

[tome]

We have a maxprop and always leave the gearbox astern to feather but don't return it to neutral until we need to use the engine

 

[vyv_cox]

Our Autoprop continues to turn when the engine is switched off. With a Yanmar we need to select astern to brake the shaft, whereas with the old Bukh 20 forward was needed. We normally leave it in astern until it is needed.

 

[StellaGirl]

Leave it in astern...

 

[Sailfree]

Interested in your comments.

We had same problem of gearbox locking up in astern with a fixed prop. Yanmar said with new gearboxes putting in astern while sailing stresses them.

We decided to fit a Variprop feathering prop. We put sails up and when we stop engine prop feathers providing we are doing say 3 to 4kts. If we put gearbox in astern it definately feathers and gearbox no longer locks up. Better performance when sailing, tremendous improvement when motoring astern or stopping boat but like you not so much power forwards.

Lack of forwards power could be explained by flat blades instead of shaped but I am checking whether the pitch adjustment is correct. ie have we got pitch for astern when going forwards as its only the pitch adjustment that differentiates between RH and LH props!

One advantage of the variprop & kiwi prop over the maxi is that the pitch can be adjusted externally and the prop fits as an assembled unit. My understanding of the maxiprop is that the pitch is set when assembling the propeller on the shaft!
Unless you are happy doing it between tides and drying out against some piles you will have to adjust the maxiprop at the next lift out.

 

[john_morris_uk]

Robert,

Pleased to hear that you have had the same positive results with your Max prop as we have. I was given some instructions with ours which suggests locking the shaft to ensure that it feathers. (It also says that for most gearboxes this means putting it in astern). Once its feathered, I have taken to putting the gearlever back in neutral so that the engine is ready for use. It also says that if you want it NOT to feather, motor astern, and then leave it in neutral - the blades will NOT feather and some boats choose to drive a shaft driven alternator or similar this way. I assume that you got the yard to fit it and they didn't leave you the destructions?

PS will be in touch ref the trip as soon as the diary is clear - as in I can see what I am doing beyond the next few hours!

 

[[2574]]

John,

Thanks - that's helpful. Yes, I obviously missed out on the destructions!

Look forward to hearing from you apropos the trip.

robert