Autopilot when crazy - 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 08-10-2008
trantor12020's Avatar
Senior Member
 
Join Date: Mar 2006
Location: Singapore
Posts: 680
Thanks: 2
Thanked 10 Times in 10 Posts
Rep Power: 9
trantor12020 is on a distinguished road
Autopilot when crazy

The other day I motor-sail solo tp an island 10 miles away to meet so,e friends for bbq and overnight. Next day as I motor back, my autopilot shows >+10deg offset from gps reading. No problem, I just set it and let it run but shortly the pilot behave crazy and started swinging the boat. I check and the pilot bearing swings all over the place. Switch it off and on again - no luck. So I continue on the journey, 1/2 hr later I put the pilot back to auto and presto! it works just fine for 1 hr then it acts up again. When this happens, I tried swinging the autopilot using the User Cal feature but it doesn't seems to help. Back at the dock the autopilot bearing looks to be normal. So what gives? I've Raymarine ST4000+ MKII Wheel with Rudder Ref Unit.
__________________
Ken
2002 Hunter 326, SV Millennium 2
1999 Macgregor 26X, SV Millennium
Reply With Quote Share with Facebook
  #2  
Old 08-10-2008
PBzeer's Avatar
Wandering Aimlessly
 
Join Date: Nov 2002
Location: Cruising
Posts: 20,258
Thanks: 0
Thanked 86 Times in 83 Posts
Rep Power: 14
PBzeer has a spectacular aura about PBzeer has a spectacular aura about PBzeer has a spectacular aura about
I'm no expert, but I would first check all the wiring related to the autopilot and make sure you're not getting a short anywhere.
__________________
John
Ontario 32 - Aria

Free, is the heart, that lives not, in fear.
Full, is the spirit, that thinks not, of falling.
True, is the soul, that hesitates not, to give.
Alive, is the one, that believes, in love.
JCP


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

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
  #3  
Old 08-10-2008
Sea Slacker
 
Join Date: Jan 2007
Posts: 1,789
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 8
brak is on a distinguished road
I'd say that this is a problem with fluxgate compass. I would check its wiring first, and also whether there are any new metal objects nearby.
Reply With Quote Share with Facebook
  #4  
Old 08-10-2008
whroeder's Avatar
Member
 
Join Date: Aug 2007
Location: Palm Bay, FL
Posts: 86
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 8
whroeder is on a distinguished road
Quote:
Originally Posted by brak View Post
I'd say that this is a problem with fluxgate compass. I would check its wiring first, and also whether there are any new metal objects nearby.
Then do the recalibrate procedure
Reply With Quote Share with Facebook
  #5  
Old 08-10-2008
Whampoa's Avatar
Senior Member
 
Join Date: Jun 2008
Location: Docked in Oriental.NC USA
Posts: 164
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 7
Whampoa is on a distinguished road
I think brak's suggestion merits looking at. Earlier this year on a trip in the Bahamas, we experienced similar behavior on a friend's catamaran after new crew members put the canned goods away. After scratching our heads for quite awhile we checked the cabinet where the flux compass is located only to find it buried under about a dozen steel canned goods. We removed the cans and didn't see the problem repeat for the rest of the trip.

I would also verify the the rudder position reference sensor is properly aligned. On our Chesapeake trip in May the autopilot on Whampoa began to act up and it would struggle to maintain a heading even in calm seas. We went over all the components carefully and found that the rudder position indicator arm was loose and had been bumped out of alignment during heavy weather. Aligning this and tightening things up resolved the problem and we continued the trip with no further problems with the autopilot.

I'm not sure how your system is set up but make sure nothing is physically interfering with the unit.

Good luck with the problem.

Regards, John
__________________
Whampoa

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

US East Coast
1962 40' Auxiliary Cutter
S.S. Crocker - Design # 330

Last edited by Whampoa; 08-10-2008 at 08:39 PM.
Reply With Quote Share with Facebook
  #6  
Old 08-10-2008
hphoen's Avatar
"Nevis Nice"
 
Join Date: Apr 2003
Location: Virginia
Posts: 224
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 12
hphoen is on a distinguished road
That happened to me, too. Motor-sailing along on autopilot, and we suddenly took an excursion.

My tool bag had made it's way across the sole and ended up next to the fluxgate compass. Moved the metal and all was OK.

I'm not saying that this was your problem, but it's something to think about.
__________________
Hud
Reply With Quote Share with Facebook
  #7  
Old 08-10-2008
Junior Member
 
Join Date: Jun 2007
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
capthor is on a distinguished road
Smile The likelyhood

Quote:
Originally Posted by trantor12020 View Post
The other day I motor-sail solo tp an island 10 miles away to meet so,e friends for bbq and overnight. Next day as I motor back, my autopilot shows >+10deg offset from gps reading. No problem, I just set it and let it run but shortly the pilot behave crazy and started swinging the boat. I check and the pilot bearing swings all over the place. Switch it off and on again - no luck. So I continue on the journey, 1/2 hr later I put the pilot back to auto and presto! it works just fine for 1 hr then it acts up again. When this happens, I tried swinging the autopilot using the User Cal feature but it doesn't seems to help. Back at the dock the autopilot bearing looks to be normal. So what gives? I've Raymarine ST4000+ MKII Wheel with Rudder Ref Unit.
Most likely you have a bad connection to your FLUXGATE COMPASS or something is stoved too close to it and makes it fluctuate on the heading.
Good luck keep smiling Capt Thor
Reply With Quote Share with Facebook
  #8  
Old 08-10-2008
sailingdog's Avatar
Telstar 28
 
Join Date: Mar 2006
Location: New England
Posts: 43,291
Thanks: 0
Thanked 11 Times in 11 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
BTW, there are a lot of things that have strong magnets in them that you might not think of. The emergency "shake" flashlights have strong permanent magnets in them. Check to make sure that there is nothing near the fluxgate compass.
__________________
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
  #9  
Old 08-10-2008
trantor12020's Avatar
Senior Member
 
Join Date: Mar 2006
Location: Singapore
Posts: 680
Thanks: 2
Thanked 10 Times in 10 Posts
Rep Power: 9
trantor12020 is on a distinguished road
Thanks guys. Now what has changed, I've put a large SS pot in the galley cabinet (close to fluxgate) that didn't seems to affect the autopilot for the trip up. After trip the pot gets transferred to another boat so I doubt that's the cause as I've done the User Cal swing as mentioned. Connections - I have to check. Rudder Sensor - I have to check the mounting since it sits on a wooden puck. There has been pretty wet weather lately so the wooden puck could have been affected some. I sure hope its not the ST4000+ Display set failing. I won't be back to boat for next 2-3 weeks (on business trip), but will reverting with findings after that. Cheers.
__________________
Ken
2002 Hunter 326, SV Millennium 2
1999 Macgregor 26X, SV Millennium
Reply With Quote Share with Facebook
  #10  
Old 08-10-2008
hellosailor's Avatar
Plausible Deniability
 
Join Date: Apr 2006
Posts: 10,711
Thanks: 2
Thanked 93 Times in 91 Posts
Rep Power: 10
hellosailor has a spectacular aura about hellosailor has a spectacular aura about
The wiring, the fluxgate, and also RFI: Radio frequency interference getting into the wiring from the compass to the autopilot, or into the autopilot's main board. RFI can take strange forms, for instance, any GSM Palm Treo (Tmobile, AT&T, etc.) will create audio noises on any computer or car stereo, etc. within two feet of it, sometimes once a day sometimes once an hour, as the phone communicates with the local towers--when it is NOT being used.

Any new gadgets aboard the boat? Any radios or bluetooth-equipped devices?

The last possibility would be that the autopilot itself has gone mad, and something is wrong in the brains of it. Could literally be a loose screw or a strand of wire floating around in there, or a cold solder joint that was working open and closed. It is worth opening up and eyeballing it with a magnifier, to see if any of the joints look bad. Cold solder joints plague all kinds of gear.
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
Fine-Tuning the Autopilot, Part Two Dan Neri Gear and Maintenance Articles 0 10-13-2003 08:00 PM
Autopilot Overview Tom Wood Gear and Maintenance Articles 0 03-22-2002 07:00 PM


All times are GMT -4. The time now is 02:01 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.