Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 04-03-2015, 05:35   #16
Registered User

Join Date: Jun 2010
Location: On my boat
Boat: Roberts 53, Love of Gaia
Posts: 80
Re: Prop Brake

Quote:
Originally Posted by Stumble View Post
Take a look at a company called Shaftlok. Frankly I find shaft breaks unjustified, but if you want one i have heard ( though have no experience with) good things about them.

I would still highly recommend looking at a feathering prop instead.
Last I looked there were no feathering props for my size boat. But it's not an option anyhow, I've had a brand new prop cast specifically for the boat. Fixed props are reliable. And no "clunk" engaging them or problems with reverse. One of my friends had a feathering prop and it wrecked his gearbox. I've seen quite a few that jammed up as well. I'll check out Shaftlok, thanks for the tip!
__________________

__________________
yttrill is offline   Reply With Quote
Old 04-03-2015, 06:58   #17
Bailing as fast as I can.
 
GILow's Avatar

Join Date: Sep 2008
Location: Adelaide, South Australia
Boat: Swanson 42
Posts: 3,585
Re: Prop Brake

First let me say that I am currently using the system recommended by grant, a loop of thin line around a coupling bolt. Very simple and cheap. A bit of a fiddle to set but not a great drama.

But I have the bits to go the same way as Lee (Banjoship) and they are very cheap and very easy to source. The brake calliper can be found at any decent trailer spares shop for $100 or less. A simple cable braking calliper. Easy. The disk likewise can be bought from the trailer spares place then dropped in to your local engineer to be matched to the coupling or if steel worries you you could get one made from stainless. Personally I don't see the need. The trailer disks live in more hostile environments than my engine bay. Most installations I have seen can soak up the extra 8 mm disk thickness at the coupling but I suppose some setups would have difficulty.

For what it is worth I put this same setup on the diff on our Toyota Coaster bus so that I could dispense with the original transmission which incorporated the hand brake. It spins at a good 3000 rpm at highway speeds and has no problem holding a 2.5 ton bus on any hill. So our1300 rpm drive shaft and a piddly little 96hp rated prop in the water won't trouble it.

Matt


Sent from my iPhone using Cruisers Sailing Forum
__________________

__________________
Very funny Scotty, now beam down my clothes.
http://www.swansonsailor.id.au
GILow is offline   Reply With Quote
Old 04-03-2015, 07:03   #18
Bailing as fast as I can.
 
GILow's Avatar

Join Date: Sep 2008
Location: Adelaide, South Australia
Boat: Swanson 42
Posts: 3,585
Re: Prop Brake

Quote:
Originally Posted by yttrill View Post
Last I looked there were no feathering props for my size boat. But it's not an option anyhow, I've had a brand new prop cast specifically for the boat. Fixed props are reliable. And no "clunk" engaging them or problems with reverse. One of my friends had a feathering prop and it wrecked his gearbox. I've seen quite a few that jammed up as well. I'll check out Shaftlok, thanks for the tip!

FWIW I have been considering a Kiwiprop for our boat. Not in a rush to decide but at least they do make a prop big enough for our 96 hp. Not sure how high they go and if you posted your hp I missed it. I will look again. Anyway I share your sentiment that feathering props are not all sweetness and light. There's a lot to be said for the dependability of a big fixed blade bucket.

Matt


Sent from my iPhone using Cruisers Sailing Forum
__________________
Very funny Scotty, now beam down my clothes.
http://www.swansonsailor.id.au
GILow is offline   Reply With Quote
Old 04-03-2015, 07:08   #19
Registered User
 
iancoombe's Avatar

Join Date: Mar 2012
Location: back at langkawi
Boat: valiant 40
Posts: 198
Re: Prop Brake

There's been talk of reduced drag if the prop is allowed to spin, I'm not sure about water but if the engine in a helicopter stops I want the rotors to keep turning to slow down the decent rate, known as auto rotation.
__________________
I've learned so much from my mistakes I'm thinking of making a few more.
iancoombe is offline   Reply With Quote
Old 04-03-2015, 07:08   #20
Bailing as fast as I can.
 
GILow's Avatar

Join Date: Sep 2008
Location: Adelaide, South Australia
Boat: Swanson 42
Posts: 3,585
Re: Prop Brake

Ha ha. Just read this carefully. You state that you have a Nissan Patrol
Motor. Any chance you have either the SD33 or ED33? We have the latter which was rare in the Patrol but the former was quite popular. 6 cylinder instead of 4. Slightly less HP but smoother.

Matt


Sent from my iPhone using Cruisers Sailing Forum
__________________
Very funny Scotty, now beam down my clothes.
http://www.swansonsailor.id.au
GILow is offline   Reply With Quote
Old 04-03-2015, 07:10   #21
Bailing as fast as I can.
 
GILow's Avatar

Join Date: Sep 2008
Location: Adelaide, South Australia
Boat: Swanson 42
Posts: 3,585
Re: Prop Brake

Quote:
Originally Posted by iancoombe View Post
There's been talk of reduced drag if the prop is allowed to spin, I'm not sure about water but if the engine in a helicopter stops I want the rotors to keep turning to slow down the decent rate, known as auto rotation.

Oh no. Don't open this can of worms! Please, it's been done to death on CF. I've read the threads and all I got was a sense of confusion plus a headache. In the end I decided that I hated the noise so much that I did not care which system created more drag.

Matt


Sent from my iPhone using Cruisers Sailing Forum
__________________
Very funny Scotty, now beam down my clothes.
http://www.swansonsailor.id.au
GILow is offline   Reply With Quote
Old 04-03-2015, 07:56   #22
Registered User

Join Date: Jun 2010
Location: On my boat
Boat: Roberts 53, Love of Gaia
Posts: 80
Re: Prop Brake

Quote:
Originally Posted by GILow View Post

But I have the bits to go the same way as Lee (Banjoship) and they are very cheap and very easy to source. The brake calliper can be found at any decent trailer spares shop for $100 or less. A simple cable braking calliper.
Trailer brake! Brilliant! Thanks!
__________________
yttrill is offline   Reply With Quote
Old 04-03-2015, 07:59   #23
Registered User

Join Date: Jun 2010
Location: On my boat
Boat: Roberts 53, Love of Gaia
Posts: 80
Re: Prop Brake

Quote:
Originally Posted by GILow View Post
Ha ha. Just read this carefully. You state that you have a Nissan Patrol
Motor. Any chance you have either the SD33 or ED33? We have the latter which was rare in the Patrol but the former was quite popular. 6 cylinder instead of 4. Slightly less HP but smoother.
ED33, 4 cylinder. Not really enough grunt for my boat, but I can't replace it. Marinised by Diecon in Brisbane. Keel cooling. 80hp. Big boat, and doesn't glide through the water like the Swannie ..
__________________
yttrill is offline   Reply With Quote
Old 04-03-2015, 08:25   #24
Marine Service Provider

Join Date: May 2012
Location: New Orleans
Boat: We have a problem... A serious addiction issue.
Posts: 3,940
Re: Prop Brake

Quote:
Originally Posted by yttrill View Post
Last I looked there were no feathering props for my size boat. But it's not an option anyhow, I've had a brand new prop cast specifically for the boat. Fixed props are reliable. And no "clunk" engaging them or problems with reverse. One of my friends had a feathering prop and it wrecked his gearbox. I've seen quite a few that jammed up as well. I'll check out Shaftlok, thanks for the tip!
MaxProp makes off the shelf models up to 50" and larger ones by request. I cant imagine you would need one much bigger than this. Other feathering prop companies tent to top out a little smaller, but up to 24" is pretty common.

Good luck.
__________________
Greg

- If animals weren't meant to be eaten then they wouldn't be made of food.
Stumble is offline   Reply With Quote
Old 04-03-2015, 15:53   #25
Bailing as fast as I can.
 
GILow's Avatar

Join Date: Sep 2008
Location: Adelaide, South Australia
Boat: Swanson 42
Posts: 3,585
Re: Prop Brake

Quote:
Originally Posted by yttrill View Post
ED33, 4 cylinder. Not really enough grunt for my boat, but I can't replace it. Marinised by Diecon in Brisbane. Keel cooling. 80hp. Big boat, and doesn't glide through the water like the Swannie ..
Yep, that's exactly the same engine and trans we have. It is probably a bit undernourished for your boat, about right for ours, you don't want to lose any performance to less than perfectly matched prop, that's for sure.

Anyhow, I double checked those prices I stated, and it turned out I was hopelessly wrong. Brake callipers are not under AU$100 each, they are under AU$50 each. I must have been thinking of a pair.

Thinking more about the disk, I remembered that for the bus I got the local engineering outfit to make the disk from scratch, as they said it would be cheaper than buying one and adapting it. I can't remember what I paid, but it was very cheap, so I believed them.

Matt
__________________
Very funny Scotty, now beam down my clothes.
http://www.swansonsailor.id.au
GILow is offline   Reply With Quote
Old 04-03-2015, 16:50   #26
Registered User
 
NahanniV's Avatar

Join Date: Mar 2011
Location: On the Boat
Boat: Finnsailer 38
Posts: 1,145
Re: Prop Brake

Quote:
Originally Posted by iancoombe View Post
Mount an alternator and enjoy the spin
The alternator will also slow it down quite a bit, reducing the noise and wear.

And of course some extra power is always good.

Cheers,
JM.
__________________
NahanniV is offline   Reply With Quote
Old 04-03-2015, 17:36   #27
cruiser

Join Date: Feb 2008
Location: North Charleston, SC
Boat: Camano Troll
Posts: 4,669
Re: Prop Brake

Quote:
Originally Posted by iancoombe View Post
Mount an alternator and enjoy the spin
Yep. And then feed the output of the alternator to an electric motor to power the boat!

Locking the shaft will introduce some drag, no doubt but if you need to lock it to protect the transmission or other equipment, you have to lock it somehow.
__________________
rwidman is offline   Reply With Quote
Old 04-03-2015, 18:38   #28
Registered User
 
Nicholson58's Avatar

Join Date: Jan 2011
Location: Live aboard
Boat: Camper & Nicholson58 Ketch - ROXY Traverse City, Michigan No.668283
Posts: 3,466
Images: 83
Re: Prop Brake

Quote:
Originally Posted by yttrill View Post
Sure but that's not suitable for me. i have a fixed prop. I need a "cheap" solution, replacing a brand new prop isn't cheap, even if there was one available for my size boat (which there wasn't when I investigated it).

I specifically chose a non-feathering prop anyhow, I don't like the complication, maintenance burden, unreliability, and stress factors involved with feathering designs. Great for race boats .. but I'm a cruiser.
You are right about the co$t. Not necessarily on the 'race boat' point. Adjustable pitch from the cockpit; 24 inch; 0-90 degree blade rotation; reversing transmission (also hydraulic). This prop is a working bruit. We adjust pitch based on sea state, speed & wind to optimize the exhaust temperature. With shallow pitch we have huge thrust at low speed. Making distance on motor alone, we make 7-9 knots at 550 rpm prop speed on flat water. If there is enough breeze to add sail we can stretch out the pitch even more.

Can you lock up the shaft through the coupling with perhaps a wood dowel? That way, if you forget it or need prop in a hurry you just shatter it.

We buy brakes from a company called HORTON. They and others make pneumatic and hand applied brakes - also no cheap. If you have space, you might fit a wheel drum with an intact emergency hand brake from a light truck. There are also a few suppliers who sell mechanical, hand-set calipers. This search will show you quite a few. https://www.google.com/search?q=pneu...Q&ved=0CCAQsAQ

One of the other posts asked why bother since there are prop shaft generators in use. I doubt they are a big assist but they rely on auto-rotation.
Attached Thumbnails
Click image for larger version

Name:	DSCF3839.jpg
Views:	88
Size:	432.8 KB
ID:	98320   Click image for larger version

Name:	PA180008.jpg
Views:	93
Size:	392.7 KB
ID:	98321  

__________________
Nicholson58 is offline   Reply With Quote
Old 08-03-2015, 01:26   #29
Registered User

Join Date: Jul 2013
Posts: 9
Re: Prop Brake

Actually a revolving prop applies more brake than one that is locked and capitate. In my humble opinion



Sent from my iPad using Cruisers Sailing Forum
__________________
vinayfm is offline   Reply With Quote
Old 08-03-2015, 04:25   #30
Bailing as fast as I can.
 
GILow's Avatar

Join Date: Sep 2008
Location: Adelaide, South Australia
Boat: Swanson 42
Posts: 3,585
Re: Prop Brake

Quote:
Originally Posted by vinayfm View Post
Actually a revolving prop applies more brake than one that is locked and capitate. In my humble opinion
And here we go again...
__________________

__________________
Very funny Scotty, now beam down my clothes.
http://www.swansonsailor.id.au
GILow is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Barlow Winch w/ Brake? What's This For? kevman1421 Deck hardware: Rigging, Sails & Hoisting 15 19-08-2015 13:58
How to Create a Shaft Brake ? Geoff H. Monohull Sailboats 14 12-05-2010 22:23
Lewmar Steering Brake Seizure seanie20 Deck hardware: Rigging, Sails & Hoisting 0 18-03-2010 17:59



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 12:00.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.