knot meter paddle wheel mystery - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > On Board > Gear & Maintenance
 Not a Member? 
  #1  
Old 06-02-2008
Senior Member
 
Join Date: Sep 2007
Posts: 171
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 7
hertfordnc is on a distinguished road
knot meter paddle wheel mystery

I have Raymarine ST4000 autopilot. with ST50 instruments. ALl works great except the speed indicator. I assumed the paddle wheel was fouled. I looked at removing it from the inside and I don't think it comes out that way.

Yesterday the water was finally warm enough to swim so I went under to have a look. There is no paddle. The place on the outside of the hull where the sensor wires end is capped off. sealed, flat, no access.

So what's going on?

Is there a solid state type that senses the water passing with no moving parts in the water?

Or was it capped off for some hull work and never uncapped?
__________________
In over my head?
First Boat, a well-equipped 1977 Camper Nicholson 31
What is all this stuff and how does it work?
Reply With Quote Share with Facebook
  #2  
Old 06-02-2008
pfatyol's Avatar
Swansea, MA
 
Join Date: Dec 2003
Location: Massachusetts
Posts: 98
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 11
pfatyol is on a distinguished road
Sounds like the dummy plug is in and not the sensor, are there wires going to the thru hull? if not then it is the filler plug.
__________________
Patrick

S/V "Fat-Kat"
C&C 32, Hull #237
Mt. Hope Bay
Reply With Quote Share with Facebook
  #3  
Old 06-02-2008
TrueBlue's Avatar
Señor Member
 
Join Date: Oct 2004
Location: Narragansett Bay
Posts: 4,853
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 12
TrueBlue is a jewel in the rough TrueBlue is a jewel in the rough TrueBlue is a jewel in the rough
Either what you saw was as Patrick noted, a dummy plug - removable from the inside of the hull, or, you're confusing the knotmeter with the depth sounder.
__________________
True Blue . . .
sold the Nauticat
Reply With Quote Share with Facebook
  #4  
Old 06-02-2008
Senior Member
 
Join Date: Sep 2007
Posts: 171
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 7
hertfordnc is on a distinguished road
Knot meter and depth sounder are next to each other just outboard of the keel about one third forward of the stern. There is a molded factory-made flat spot in the hull for the two sensors.


I followed two wires from the instruments. I am not sure which is which but I figured when I got under the boat it would be obvious.

From the inside the wires lead to plastic threaded ends, one is about 2" and the other is less than an inch. The wires are bedded in a silicone product. A threaded collar is easily movable from both devices but when removed it does not appear that the sensor comes out from the inside. The threaded collar seems to be pulling it snug to the hull, suggesting it is only removed from the outside.

I've researched what a typical installation is supposed to look like and this is apparently not typical.

Now back to my questions;


Are there other ways this thing might have been put together?

Or, is it likely that a factory made cap was put on the outside for hull work?

Or, is there such a thing as a solid state water flow meter that works with Raymarine ST50 ?

thanks
__________________
In over my head?
First Boat, a well-equipped 1977 Camper Nicholson 31
What is all this stuff and how does it work?

Last edited by hertfordnc; 06-02-2008 at 09:57 AM.
Reply With Quote Share with Facebook
  #5  
Old 06-02-2008
Member
 
Join Date: May 2008
Posts: 33
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
bettyswollocks is on a distinguished road
If it looks like my one from the inside you will have a metal pin going across with a small circlip in the middle. Remove them both then undo the large plastic ring counterclockwise. Put the pin back in to give you leverage and twist back and forth while pulling. It will gradually (depending on how fouled up it is) come out. Be prepared for a real flood.....have a bung ready as you would not believe just how much pressure it has behind it, especially when you are trying to get the bung in.
I have to do my one after only 2 weeks of no use. It doesn't take a lot to stop it spinning. If it hasn't been used for a while you are much better off taking it out as above as you just wont be able to do as good a job while it is under the boat.
Reply With Quote Share with Facebook
  #6  
Old 06-02-2008
Senior Member
 
Join Date: Sep 2007
Posts: 171
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 7
hertfordnc is on a distinguished road
no metal pin, no clip, no evidence that it comes out from the inside. I'll try to add photos.
__________________
In over my head?
First Boat, a well-equipped 1977 Camper Nicholson 31
What is all this stuff and how does it work?
Reply With Quote Share with Facebook
  #7  
Old 06-02-2008
erps's Avatar
the pointy end is the bow
 
Join Date: Aug 2006
Location: La Conner, Washington
Posts: 6,149
Thanks: 2
Thanked 24 Times in 24 Posts
Rep Power: 10
erps will become famous soon enough erps will become famous soon enough
We've had three boats with knot meters on them now. All of them had some sort of paddle wheel on them. All of them also had a dummy plug that we used to put in during the off season so the paddle wheel wouldn't foul so bad. The dummy plug didn't have wires going to it though, so I don't know how they could be confused. Pulling out the paddle wheel and sticking in the dummy plug while the boat is in the water has been discussed here before. It certainly got my heart rate up each time I did it.

I think it's going to take pictures so the guys can better understand your situation.
__________________
Ray
S.V. Nikko
1983 Fraser 41
La Conner, WA


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


Boating for over 25 years, some of them successfully.
Reply With Quote Share with Facebook
  #8  
Old 06-02-2008
BarryL's Avatar
Senior Member
 
Join Date: Aug 2003
Location: Long Island, NY
Posts: 1,599
Thanks: 3
Thanked 25 Times in 24 Posts
Rep Power: 12
BarryL is on a distinguished road
depth transducer

Quote:
Originally Posted by hertfordnc View Post
From the inside the wires lead to plastic threaded ends, one is about 2" and the other is less than an inch. The wires are bedded in a silicone product. A threaded collar is easily movable from both devices but when removed it does not appear that the sensor comes out from the inside. The threaded collar seems to be pulling it snug to the hull, suggesting it is only removed from the outside.
Your description matches what a depth finder transducer looks like. Perhaps you have two depth transducers, an old one that is not in service and a newer one for your current instrument.

Usually, the depth and speed transducers are placed on opposite sides of the boat. At least that's the way it is on most boats I have seen. I would look around for another transducer.

Good luck,
Barry
__________________
Barry Lenoble
Deep Blue C, 2002 C&C 110
Mt. Sinai, NY

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
  #9  
Old 06-02-2008
sailingdog's Avatar
Telstar 28
 
Join Date: Mar 2006
Location: New England
Posts: 43,291
Thanks: 0
Thanked 9 Times in 9 Posts
Rep Power: 13
sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice
Airmar does make a solid state speed transducer, but it is very rare and the piece is bronze and looks like this:



If yours doesn't look like this, it is either a depth transducer or a dummy plug.
__________________
Sailingdog

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Telstar 28
New England

You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.

—Cpt. Mal Reynolds, Serenity (edited)

If you're new to the Sailnet Forums... please read this
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
.

Still—DON'T READ THAT POST AGAIN.
Reply With Quote Share with Facebook
  #10  
Old 06-03-2008
Senior Member
 
Join Date: Sep 2007
Posts: 171
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 7
hertfordnc is on a distinguished road
Thanks Dog. There was a second depth finder on the boat. Vinatage with a spinning orange light flickering the depth. Now that I think about it, it appeared to read correctly at the pier but I never checked it out underway. It may have been connected. That would explain the two sensors I found.

I'll keep looking.
__________________
In over my head?
First Boat, a well-equipped 1977 Camper Nicholson 31
What is all this stuff and how does it work?
Reply With Quote Share with Facebook
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Standard horizon Sl-1 digital knot meter needed TJay Gear & Maintenance 5 05-05-2009 03:31 PM
knot meter paddle thingy hertfordnc Gear & Maintenance 6 05-03-2008 03:44 PM
Seven Knots You Can't Live Without Sue & Larry Learning to Sail Articles 0 11-14-1998 07:00 PM


All times are GMT -4. The time now is 05:53 PM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.