Author Topic: fluxgate location  (Read 1458 times)

stevesailing

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fluxgate location
« on: March 17, 2016, 06:30:41 PM »
Hi,

I'm in the process of reimplementing an autopilot. The previous one was an autohelm ST5000 but many of the components were missing. I've now finished the physical installation of a Raymarine smart pilot 30 and going through the calibration process am having difficulty with the fluxgate compass. Following RM's advice I've located it where it thought it was not close to ferrous metals or electrical  current,  and central in the boat. I went for a spot just to one side of the mast foot but it won't complete the deviation calibration step. So I'm wondering if there is any ferrous metal in the keel that might be disturbing it. Does anyone know what the keel on a 44W/O is made from?

Cheers,

Steve

Matthew Balch

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  • Boat Name: Chilly Pepper
Re: fluxgate location
« Reply #1 on: March 17, 2016, 08:30:12 PM »
Hi Steve,

My Flux gate compass  is located in the forward shower room, near the floor and the door.  It's  a different manufacturer,  but it works fine for me in that location.  Not too far away from the location you described, but just a little bit forward of that.  I believe the keel is lead.  Ferrous spare parts stowed under the seating may disturb the settings, so you might want to check to see if that is causing any interference with the fluxgate.

Matthew

Una Mas

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Re: fluxgate location
« Reply #2 on: March 18, 2016, 12:08:34 PM »
Is your mast keel or deck stepped? If keel stepped, wiring running down may be causing some EMI. (Electromagnetic interference)
Try taking a handheld compass and moving it around in different locations to check for deviation. That can give you clues.

Most manufacturers recommend the back 3rd of the boat for location but that's a tough one on most vessels.

Darrin

deLight

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Re: fluxgate location
« Reply #3 on: March 19, 2016, 01:28:13 PM »
The autopilot on deLight did not work well when I bought the boat. I suspected it was the fluxgate compass location.

I decided to relocate it to the center of movement of the boat. So, on several ocean passages, I experimented by placing an object on the floor and trying to find a place where it would stay put no matter what gyrations the boat went through.

I found that spot and mounted the fluxgate as close to it as possible. The autopilot has worked well since.

Max

Chip

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Re: fluxgate location
« Reply #4 on: March 31, 2016, 08:58:10 PM »
I am working on my third autopilot a Garmin, the prior ones were an Autohelm and a Raymarine. The compass for all is between the drawer and the bulkhead under the aft bunk. This has worked well in all three cases.

stevesailing

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Re: fluxgate location
« Reply #5 on: April 03, 2016, 07:40:04 PM »
thanks all for the information - further testing has revealed that it is likely a course computer problem (sigh). next thing will be to try using a NMEA 0183 compass to get the heading data rather than the dedicated fluxgate input.

Cheers,

Steve