PDA

View Full Version : Prop Shaft Lock



tboussie
07-01-2017, 12:29 PM
Perhaps a simple question, but I am wondering how people lock off their prop shaft while they are charging their batteries under sail. If I put my transmission in neutral while sailing, the shaft spins like mad. I typically put the transmission in reverse with the engine off to lock the shaft with the folding blades closed.

I would like to lock the prop off to charge the batteries, but in a way that can easily be overridden if I need to engage the engine in an emergency situation (i.e. without having to go below, undo something from the shaft, etc.). Any ideas?

JimQuanci
07-02-2017, 10:22 AM
On locking the shaft by putting the transmission in reverse... note that works for folding props but will lock most feathering props open (ie you are sailing dragging a bucket behind you). Maxprop recommends turning the engine iff with the transmission still in gear... the boats forward motion will then feather the prop...and then later putting in neutral. Best wishes!

Gamayun
07-10-2017, 12:05 AM
On locking the shaft by putting the transmission in reverse... note that works for folding props but will lock most feathering props open (ie you are sailing dragging a bucket behind you). Maxprop recommends turning the engine iff with the transmission still in gear... the boats forward motion will then feather the prop...and then later putting in neutral. Best wishes!

Oh my. I think I've been dragging a bucket. I've been putting my relatively recent MaxProp in reverse when I sail. Looks like I need to go back and read the instructions more closely. Dang....

BobJ
07-10-2017, 07:42 PM
Uh oh. Now she's gonna start beating us.

The Smokester
07-11-2017, 06:48 PM
Oh my. I think I've been dragging a bucket. I've been putting my relatively recent MaxProp in reverse when I sail. Looks like I need to go back and read the instructions more closely. Dang....

Depends on your setup...My Yanmar recommends leaving transmission in neutral.

Gamayun
07-12-2017, 01:44 AM
Depends on your setup...My Yanmar recommends leaving transmission in neutral.

Yes, I used to keep it in neutral when I had the fixed prop on. My engine is also a Yanmar. Does the same hold for the folding props? Argh. Just when I think I have SOME of these things figured out.....

The Smokester
07-12-2017, 07:35 AM
Yes, I used to keep it in neutral when I had the fixed prop on. My engine is also a Yanmar. Does the same hold for the folding props? Argh. Just when I think I have SOME of these things figured out.....

We need to do an experiment...

BobJ
07-12-2017, 08:08 AM
That's what I was thinking.

After 15 years of always closing the prop in the same sequence, Dave came aboard and did it in a different order, which worked just fine. So a second pair of eyes, plus listening/feeling the boat and watching the knotmeter, is the way to work it out. In my boat's case it also helps to know when the folded prop is in the least turbulent position but you'd need a diver for that. Do you happen to know one?

Wylieguy
07-12-2017, 08:22 AM
When I sailed my Newport 30 with an Atomic 4 and a simple folding 2-blade prop l marked the prop shaft when the blades were folded alongside the shaft. A scribe mark. To "lock" the prop I'd dive into the cockpit hatch with a "C" clamp, align the mark up and clamp the shaft just enough to keep it from hand turning. Of course I had to remember to reverse the procedure. But if I forgot, don't ask, the force of the engine would toss the clamp off with a thud to remind me to remember the next time.

Gamayun
07-12-2017, 07:51 PM
That's what I was thinking.

After 15 years of always closing the prop in the same sequence, Dave came aboard and did it in a different order, which worked just fine. So a second pair of eyes, plus listening/feeling the boat and watching the knotmeter, is the way to work it out. In my boat's case it also helps to know when the folded prop is in the least turbulent position but you'd need a diver for that. Do you happen to know one?

Hey yeah, hmmm, no wait, errr.....does this mean I would have to be towed off the back, holding on and looking at the prop, while it goes into forward, reverse or neutral? Sounds like a good way to earn a Darwin Award :(

BobJ
07-12-2017, 08:23 PM
Well you COULD do it that way (can I watch?) But no, with the boat in the slip (engine off) you turn the closed prop to where you want it then climb aboard, go below and mark the shaft. On mine that's where the blades open horizontally, so the gap between them when closed is aligned with the strut.

Then like Pat wrote, when you turn off the engine before your race start, you jump below and turn the shaft so the mark (and closed prop) is where you want it. BTW, I only go to this trouble for an ocean race.

(Massive edit there - I hope this makes sense.)
.