Does your folding prop turn when sailing?

Ric

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I was surprised after I fitted a folding prop that (like the old fixed prop) it turns while sailing, and I have to pop the gearbox in reverse to stop it. I had assumed that it would fold in the slipstream and therefore not turn when sailing.

I'm still intrigued why this should be. If I stop the prop turning so that it folds (I know it folds properly because of the performance increase) then release it, it still starts to turn again. The torque is fairly substantial, suggesting that the blades are opening out.
 

All_at_Sea

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Bruntons autoprop

Mine turns when sailing so l have a shaft brake as l also have a hydraulic gearbox, so putting in reverse will not work. These props are designed to do this so when you engage gear they quickly get into the correct position to drive the boat fwd or back.
 

ChrisE

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Mine turns when sailing so l have a shaft brake as l also have a hydraulic gearbox, so putting in reverse will not work. These props are designed to do this so when you engage gear they quickly get into the correct position to drive the boat fwd or back.

In the blurb you get with the Autoprop it tells you to turn the engine off and leave in gear which causes the prop to fold for my non-hydraulic gearbox.
 

basil421

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I too have a folding 2 blade prop. I don't know if it actually turns while sailing but it does vibrate. I have found if I put it in reverse this stops the noise. I must look next season and see if the shaft actually turns when it's not in gear.
 

rob2

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Yes, mine does. More modern folding props are much quicker to unfold than their predecessors, so they do so when sailing. On the plus side, because they are not turning and exert little load on the shaft when the gearbox is in reverse, you are much less likely to have problems getting back into neutral ready to restart the engine - a common problem with a fixed prop. That problem in itself is not so bad unless you have a gear lock on the starter!

Rob.
 

windpipe

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This sounds the norm to me, most folding props will need to be put into gear to stop the prop spinning, especially if it is 3 or 4 bladed. The do of course start to fold without engaging the gear but its the very last bit of folding that needs the prop shaft to be locked into position.
 
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