Raymarine SPX 5 causing excessive magnetic deviation

Blue Fox

Blue Fox

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Since mounting my spx 5 wheel drive my compass has developed a considerable magnetic deviation (15 to 20 degrees). I am sure it is caused by the wheelpilot. If I remove the motordrive, the deviation is gone. The drive is mounted at the lowest position - so can't be further away from my binnacle compass.
I sent a mail to Raymarine, but - apart from acknowledging my question ('will be answered within 24 hours') - they don't react. The Dutch importer doesn't react either.
Very strange this. You shouldn't design an autopilot with such a strong magnetic field, shouldn't you? And if you do it, shouldn't you recognize the problem towards your clients, instead of keeping a radio silence?
Are there other users having the same problem?
And: what can I do about it? Is there a way of shielding my compass? A leaden sheet around the motor, perhaps?
chris
 
Sorry I can't offer you an answer, just confirm that you're not the only one. I notice a considerable difference of opinion between my traditional magnetic compass on the binnacle and the fluxgate compass inside the aft cabin locker. On the basis that the binnacle compass is surrounded by lumps of metal and electronics and the fluxgate isn't, I feel more inclined to believe the latter. But if the electronics goes down ............ ?!

I wonder if it's the presence of metal or the presence of electromagnetic fields that upset the compass. Unfortunately there is no way of telling because when I switch off all the electrical/electronic gear I don't know what the fluxgate is reading.
 
Is this a common problem?

I cannot answer the OP’s original question, but wonder how often this sort of problem occurs. On my boat, the fluxgate compass and the main compass have significantly different deviations, although the fluxgate has the correct offset applied which makes both read true north when genuinely heading north (only). My problem occurs when trying to use the GPS to steer to a waypoint as the course-to-steer that it calculates never matches the fluxgate compass’s view of the world. It is so bad that I cannot use the NAV mode on the B and G Network Pilot to steer to waypoints as the boat never goes in the heading that the GPS has calculated.

I’ve often wondered whether there is something causing the fluxgate compass to become disorientated (deviated), such as the motor for the hydraulic pump or the Eber heater. I don’t think I can set up the Network Pilot to ignore the fluxgate compass and use the GPS COG which might get round this (though the GPS COG is probably too slow to keep the boat on a straight line when sailing).

So, in response to the original query, I cannot help, but can sympathise…
 
trapezeartist said:
I wonder if it's the presence of metal or the presence of electromagnetic fields that upset the compass. Unfortunately there is no way of telling because when I switch off all the electrical/electronic gear I don't know what the fluxgate is reading.
Click to expand...
In my case there is no difference if the wheelpilot is off: the deviation stays the same. The fluxgate is not reliable as well - sometimes gives erratic readings. But that may be because I don't always have the GPS on, that's linked to the SPX5.
 
from memory, you have to "swing" the fluxgate compass which detects and adjusts for magnetic interference and also tells you if you have too much inteferance, have you followed that prodecure carefully, think you have to turn the boat very slowly in circles very slowly a couple of times, double check the manual?
 
mattnj said:
from memory, you have to "swing" the fluxgate compass which detects and adjusts for magnetic interference and also tells you if you have too much inteferance, have you followed that prodecure carefully, think you have to turn the boat very slowly in circles very slowly a couple of times, double check the manual?
Click to expand...

Our SPX5 was the same, but after spending half an hour going round in circles in the Markemeer it was fine, think ours just needed to be calibrated, or so my hubby said anyway.
 
mattnj said:
from memory, you have to "swing" the fluxgate compass which detects and adjusts for magnetic interference and also tells you if you have too much inteferance, have you followed that prodecure carefully, think you have to turn the boat very slowly in circles very slowly a couple of times, double check the manual?
Click to expand...

I have just fitted a spx 5 and was about to calibrate it last weekend, when it mentioned about being wired up to the gps, and swinging the compass in the calibration mode, so had to cancel the calibration until i got a nmea cable, which i intend to fit this weekend and then spend the bank holiday weekend going around in circles.

To anyone who has done this already, does the compass then show a correct setting, as at the moment mine is showing at least 90' difference, before calibration.

Anyone who knows me, please don't call the rnli to a yacht going around in circles, i will just be going thru the calibration mode. thanks..
 
colvic987 said:
I have just fitted a spx 5 and was about to calibrate it last weekend, when it mentioned about being wired up to the gps, and swinging the compass in the calibration mode, so had to cancel the calibration until i got a nmea cable, which i intend to fit this weekend and then spend the bank holiday weekend going around in circles.

To anyone who has done this already, does the compass then show a correct setting, as at the moment mine is showing at least 90' difference, before calibration.

Anyone who knows me, please don't call the rnli to a yacht going around in circles, i will just be going thru the calibration mode. thanks..
Click to expand...

Our compass is now showing the correct heading, before it was calibrated like yours it was wrong
 
Blue Fox said:
Since mounting my spx 5 wheel drive my compass has developed a considerable magnetic deviation (15 to 20 degrees). I am sure it is caused by the wheelpilot. If I remove the motordrive, the deviation is gone. The drive is mounted at the lowest position - so can't be further away from my binnacle compass.
I sent a mail to Raymarine, but - apart from acknowledging my question ('will be answered within 24 hours') - they don't react. The Dutch importer doesn't react either.
Very strange this. You shouldn't design an autopilot with such a strong magnetic field, shouldn't you? And if you do it, shouldn't you recognize the problem towards your clients, instead of keeping a radio silence?
Are there other users having the same problem?
And: what can I do about it? Is there a way of shielding my compass? A leaden sheet around the motor, perhaps?
chris
Click to expand...


page 16 of your manual, have you used slot 1 or slot 2, if you have used slot 2 your compass might be affected,
 
No, I have used the slot that puts the drive at the lowest possible position - I have seen the warning in the manual. But the field is so strong, there's no way the binnacle compass is working OK. Yes, by lifting it out of the binnacle and raise it about 30 cm. I'm afraid making a deviation graph is now the only option. But there are courses where the deviation is 20 degrees!
My fluxgate (mounted inside in the cabin) will work allright after doing the selflearning tricks or when I connect the GPS. But if I turn the wheelpilot off and on without the GPS, the deviation in the fluxgate will return. No problem, because I don't like to set the pilot to sail to a waypoint, but apparently the memory is not working.
 
Same problem

About a year ago I tried to fit the same unit to a friends Ronautica with exactly the same outcome you have stated. Even on the lowest setting. The deviation was that bad that there was no way you could have adjusted it out of the binacle compass. He contacted Raymarine who told him to check inside the motor housing as there should be a screen which prevents this problem. He checked and found that although their was in fact a screen it was too short and as a result was not able to perform its function correctly. He eventually gave the unit back to the supplier and got a full refund.
 
colvic987 said:
thanks for that quick reply, nice to know how quick the information can flow on this site.
Click to expand...

Unfortunately, the reply you got from Icarus39 was incomplete. There are 2 stages to the calibration process. The first (motoring gently in circles) is a linearisation procedure, which serves only to calculate the maximum deviation. The second part is to manually adjust the heading setting to correspond with the boat's actual heading. Only then will the fluxgate give a reasonably accurate heading output.
 
Unfortunately but predictably, the OP and others have encountered a problem-area that has been with pro mariners ( and aviators ) as long as magnetic compasses have been with us.

The installation of so many more sources of powerful deviating influences - autopilots, instrument clusters, high voltage cables, cockpit VHF speakers and handmikes, and multiple other recently-become-essential items of kit - has made the once simple, rugged and reliable compass a source of error and concern to many.

Maritime professionals have their compasses calibrated and corrected by qualified, certificated 'Compass Adjusters'. It's a profession. The same is done with commercial aircraft. The marine electronics industry knows all about this, but does nothing effective to resolve the issues for their customers.

Resolving such now-complex problems lies rather beyond the DIY capabilities of most 'yotties' - although some will be along soon, no doubt, to tell us all how clever they've been, having half-read a 3-page pamphlet on compass theory a dozen years ago.

The only solution costs money ( but not much ) - hire a pro to fix it.
 
Lady Campanula said:
Unfortunately but predictably, the OP and others have encountered a problem-area that has been with pro mariners ( and aviators ) as long as magnetic compasses have been with us.

The installation of so many more sources of powerful deviating influences - autopilots, instrument clusters, high voltage cables, cockpit VHF speakers and handmikes, and multiple other recently-become-essential items of kit - has made the once simple, rugged and reliable compass a source of error and concern to many.

Maritime professionals have their compasses calibrated and corrected by qualified, certificated 'Compass Adjusters'. It's a profession. The same is done with commercial aircraft. The marine electronics industry knows all about this, but does nothing effective to resolve the issues for their customers.

Resolving such now-complex problems lies rather beyond the DIY capabilities of most 'yotties' - although some will be along soon, no doubt, to tell us all how clever they've been, having half-read a 3-page pamphlet on compass theory a dozen years ago.

The only solution costs money ( but not much ) - hire a pro to fix it.
Click to expand...

Whilst agreeing with what you are saying in general principle. I think the point here is the fact that this particular design has an inherent design fault due to a lack of effective magnetic screening. If this item was to be installed in the stated vessels then the compass would end up with a variable (and unpredictable) variation that would change everytime the autopilot was brought into use and then disengaged. No amount of compass calibration could ever compensate for these variable and unpredictable changes. The only possible solutions would either be to change the compass location dramatically or fix the design fault by improving the screening.
 
radarman said:
Whilst agreeing with what you are saying in general principle. I think the point here is the fact that this particular design has an inherent design fault due to a lack of effective magnetic screening. If this item was to be installed in the stated vessels then the compass would end up with a variable (and unpredictable) variation that would change everytime the autopilot was brought into use and then disengaged. No amount of compass calibration could ever compensate for these variable and unpredictable changes. The only possible solutions would either be to change the compass location dramatically or fix the design fault by improving the screening.
Click to expand...

With all the respect I can muster at this time of the morning, this is not a matter of general principle, but of particular and specific professional application of deep knowledge and long experience. This is what a Compass Adjuster does.

No, there are other solutions than the two so dogmatically asserted above, and a pro will be able to evaluate and recommend appropriately. An amateur, on here? Well, 'ye pays yer money and ye takes yer chances'.

I am certain the OP will be able to find a pro Compass Adjuster near his boat in the Nederlands, and seek pro guidance.
 
Last edited:
SPX5 wheel autopilot effects on binacle compass

Glad I stumbled upon these threads regarding the SPX5 having gone round in circles and digested page after page of Raymarine instructions.I purchased this unit in July and despite a number of conversations with Raymarine(who were pleasant and helpful) there was no admitting a fault regarding the motor unit causing abnormal readings on my Sunto compass.
Having sat on the bow with a handheld compass my readings matched the fuxgate readings give or take a degree or two.
It is naturally reassuring to have a correctly adjusted binacle compass and disappointing to say the least that Raymarine are not willing to rectify this issue considering the cost of the SPX5 wheel unit.
 
colvic987 said:
To anyone who has done this already, does the compass then show a correct setting, as at the moment mine is showing at least 90' difference, before calibration.

Anyone who knows me, please don't call the rnli to a yacht going around in circles, i will just be going thru the calibration mode. thanks..
Click to expand...

The calibration circles just work out the deviation. Once you have successfully done that you have to adjust the heading, by steering a straight course and entering the heading from a transit bearing, hand bearing compass or if your GPS etc. is linked in you can use the COG.
 
santana said:
Glad I stumbled upon these threads regarding the SPX5 having gone round in circles and digested page after page of Raymarine instructions.I purchased this unit in July and despite a number of conversations with Raymarine(who were pleasant and helpful) there was no admitting a fault regarding the motor unit causing abnormal readings on my Sunto compass.
Having sat on the bow with a handheld compass my readings matched the fuxgate readings give or take a degree or two.
It is naturally reassuring to have a correctly adjusted binacle compass and disappointing to say the least that Raymarine are not willing to rectify this issue considering the cost of the SPX5 wheel unit.
Click to expand...

Well, at least you got an answer! Neither Raymarine nor the (Dutch) importer has ever reacted to my mails concerning this matter.
Chris
 
colvic987 said:
page 16 of your manual, have you used slot 1 or slot 2, if you have used slot 2 your compass might be affected,
Click to expand...
Trying to find out if its possible to cut another slot to use for the pedestal bracket - one position badly affects the binacle compass, other position power cable cant be fitted as it clashes with engine command unit - anyone out there tried adding another slot ?
 
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