My new to me 14M motorsailor pulled dramatically to starboard under any more than 1/2 power. Powering up on the jetty it was apparent the wash from the 26" traditional screw was pushing the rudder
over rather than prop walk causing the problem.
The original owner had fitted a very well engineered shaft alternator
arrangement, when handing over the boat he did suggest that I may want to fit a smaller prop, I was not aware then of the steering
problem, only when delivering the boat in heavy weather
to the UK from Holland
. He said he fitted a large prop to power the alternator
as the boat is very electric
Anyway, I panicked when I realised the extent of the problem, it was so bad I was going to sell the boat on if I could not fix it and take a hit.
A friend suggested I call Axiom Propellers as their prop created a different flow from traditional screws. I ordered a left handed 24" and hauled out to fit it. Pictures shown...
While the boat was out realised that the old prop was fitted 6" away from P bracket cutlass bearing, and was closer to the rudder
than it needed to be. So managed to cut the shaft in situ by the alternator arrangement fortunately without dropping the rudder.
The net result now: I get no pull at all to starboard in forward even under full power, can take my hand off the wheel
and the boat serenely goes straight ahead. Speed is the same as with old prop, maybe slightly more even. I can see the wash is different and there is no wiggle on wheel
which there was before, very sensitive steering
with semi balanced rudder.
Going astern there is very slight prop walk, but hardly any, (glad I have a good bowthruster) otherwise that could have been a problem.
Under sail the prop does drive the alternator OK. What I don't know yet is how much extra drag the prop has when sailing as it looks a lot from the very flat design, however Axiom are in the process of designing a folding version. As I motor
sail a lot and am not planning any oceans for the foreseeable I will hold that in reserve.
So, so far I can recommend this prop if you have issues like I had....it will solve them as the flow off the prop is definately different to traditional screws. It may well be more efficient. The designer
did say that he could alter the pitch
slightly if needed. He was so confident that his prop would solve the problem he offered a money
back guarantee. He had to make a special casting as never made a left handed prop before anywhere near this size.