OK am still in the planning stage of autopilot installation and am haveing trouble figuring out where to install the compass so it doesn't interact with anything magnetic. The problem is, everywhere I look there is something. Electrical wires for lights, instraments, galley storage (both drawers for silverware, etc. and stowage for provisions = cans) .... The instructions also say to mount it near the center line and in the back half of the boat - that reduces options even more. Am I driving myself crazy for no reason? Or should I keep looking?
Fluxgate compass installation for autopilot
- Thread starter Debra B
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On our Boat
Debra, The marina where we purchased our boat installed our autopilot. They installed it under the back bunk about a foot and a half to starboard of the centerline. When it comes to following the installion instructions, I personally do not think you are being overzealous but you need to do the best you can with the situation you have and then let it go. We keep non mettalic things in this area since it very shallow anyway. The closest metal is about 3 feet away and it is a stainless pot which is not magnetic. Our works fine good luck, Mike D
Debra, The marina where we purchased our boat installed our autopilot. They installed it under the back bunk about a foot and a half to starboard of the centerline. When it comes to following the installion instructions, I personally do not think you are being overzealous but you need to do the best you can with the situation you have and then let it go. We keep non mettalic things in this area since it very shallow anyway. The closest metal is about 3 feet away and it is a stainless pot which is not magnetic. Our works fine good luck, Mike D
Mine is undere the hatch way
Debra, You didn't say what boat you have. I have a '88 Catalina 30 and when I installed my my autopilot last year, I mounted the flux gate tranducer just under the hatch way behind the stairs. It is on the vertical panel of the aft quarter berth. I check out the area with a compass to see if the location was impacted by wiring, metal or the engine.
Debra, You didn't say what boat you have. I have a '88 Catalina 30 and when I installed my my autopilot last year, I mounted the flux gate tranducer just under the hatch way behind the stairs. It is on the vertical panel of the aft quarter berth. I check out the area with a compass to see if the location was impacted by wiring, metal or the engine.
No, You're Not Crazy
Debra Do a Forum Archive Search on "ST4000" The placement is important. Everyone who has posted has a boat with the similar configurations and wiring, and have finally found a place for their flux-gates. You CAN make it work, you just have to be patient. Stu PS 1. What size boat? Why not add it to your sign-in? 2. Silverware, unless you have it energized, won't hurt. It's moving electrons, not the static ones, that affect the fluxgate compass. 3. Nice to have silverware, not just plastic spoons and forks, on board.
Debra Do a Forum Archive Search on "ST4000" The placement is important. Everyone who has posted has a boat with the similar configurations and wiring, and have finally found a place for their flux-gates. You CAN make it work, you just have to be patient. Stu PS 1. What size boat? Why not add it to your sign-in? 2. Silverware, unless you have it energized, won't hurt. It's moving electrons, not the static ones, that affect the fluxgate compass. 3. Nice to have silverware, not just plastic spoons and forks, on board.
Compass Location
The Raymarine recommendations are conservative and Stu is on target, flowing electrons are the culprit (except for magnets in motors, etc). Try for the centerline. A handheld compass will help you find a suitable position. Jon McClain
The Raymarine recommendations are conservative and Stu is on target, flowing electrons are the culprit (except for magnets in motors, etc). Try for the centerline. A handheld compass will help you find a suitable position. Jon McClain
Don't worry about planning too much!
Don't fret the location for the compass: pick a place that's convenient and put it there temporarily, don't trim the wires short or bother routing them nicely. Once everything is hooked up you have to calibrate the compass deviation (done by driving slow circles for the Raymarine pilots, not sure of the procedure for others). If that process says you have too much deviation, you can move the compass (again, temporarily) to a less convenient spot, until you find a place where its happy. On our Catalina 36 I mounted the course computer on the centerline under the companionway, the compass is on the same bulkhead about a foot to port. I fully expected this location to be too close to the engine and the microwave and the exhaust elbow but I figured I'd try the easy location first and see if the deviation was okay...to my amazement, when I turned on the system and drove the required circles to swing the compass, the deviation was well within the limits specified in the install directions! I immediately stopped buying lottery tickets, figuring I had used my good luck quota for the year... After 2000 miles, the autopilot has worked flawlessly so I guess it really is an okay location...Except for the one time we hung a bag of empty steel cans over the compass, but that's another story.
Don't fret the location for the compass: pick a place that's convenient and put it there temporarily, don't trim the wires short or bother routing them nicely. Once everything is hooked up you have to calibrate the compass deviation (done by driving slow circles for the Raymarine pilots, not sure of the procedure for others). If that process says you have too much deviation, you can move the compass (again, temporarily) to a less convenient spot, until you find a place where its happy. On our Catalina 36 I mounted the course computer on the centerline under the companionway, the compass is on the same bulkhead about a foot to port. I fully expected this location to be too close to the engine and the microwave and the exhaust elbow but I figured I'd try the easy location first and see if the deviation was okay...to my amazement, when I turned on the system and drove the required circles to swing the compass, the deviation was well within the limits specified in the install directions! I immediately stopped buying lottery tickets, figuring I had used my good luck quota for the year... After 2000 miles, the autopilot has worked flawlessly so I guess it really is an okay location...Except for the one time we hung a bag of empty steel cans over the compass, but that's another story.
Where fulgate compass
What boat do you have,my fulgate is in the rear bert under the cockpit,in one of the storage compartments under the cushion a little offset the centerline. nick
What boat do you have,my fulgate is in the rear bert under the cockpit,in one of the storage compartments under the cushion a little offset the centerline. nick
Yes and Yes
Am I driving myself crazy for no reason? Ans: Yes Or should I keep looking? Ans: Yes Changing electrical magnetic fields will have a disasterous affect on the fluxgate compass. When the field increases or decreases the fluxgate will sense the changes. With regard to other ferrous metal objects - the ones that don't have a changing field - they will also have an affect but slightly different. In effect, these other objects will force the fluxgate to sort of "look through a fog" to see the earth's magnetic field, that is, make it more difficult and in the worst case, impossible. Major fixed ferrous things to watch out for would be speakers with fixed magnets, an iron keel, and the engine. Certainly there are other items. Itn't it interesting that people seem to have more problems with the technologically newer ST4000 than they had with the 15 year-old 4000? The old 4000 was a cockpit-mounted unit which was basically away from most of the metalic stuff that messed up the neighborhood. To put ferrous stuff around it one had to really work at it. On the other hand, the newer ST unit people are installing below deck where the earth's magnetic field is more contaminated and that's why they're having more problems - this is just my opinion. Moveable ferous items like a storm anchor, the metal 5-gallon gas tank for the outboard, etc. the tin cans you mentioned, will also have a changing effect. With my autopilot I use it just to keep the boat going in the direction I want but I keep track of what's hapening. I don't use it's magnetic bearing as gospel. Sometimes it's magnetic bearing can be way off but it still steers the course I toggle in. Other times the autopilot just doesn't seem that sensitive and it's probably because of all the ferrous junk I have in it's neighborhood. As an adjunct I have a good Wheems & Plath Venus which is what I'll rely on if things get really tough. P.S. Look out for that heavy steel boat that goes by close abeam! If the fluxgate picks it up it'll steer the boat right for it!
Am I driving myself crazy for no reason? Ans: Yes Or should I keep looking? Ans: Yes Changing electrical magnetic fields will have a disasterous affect on the fluxgate compass. When the field increases or decreases the fluxgate will sense the changes. With regard to other ferrous metal objects - the ones that don't have a changing field - they will also have an affect but slightly different. In effect, these other objects will force the fluxgate to sort of "look through a fog" to see the earth's magnetic field, that is, make it more difficult and in the worst case, impossible. Major fixed ferrous things to watch out for would be speakers with fixed magnets, an iron keel, and the engine. Certainly there are other items. Itn't it interesting that people seem to have more problems with the technologically newer ST4000 than they had with the 15 year-old 4000? The old 4000 was a cockpit-mounted unit which was basically away from most of the metalic stuff that messed up the neighborhood. To put ferrous stuff around it one had to really work at it. On the other hand, the newer ST unit people are installing below deck where the earth's magnetic field is more contaminated and that's why they're having more problems - this is just my opinion. Moveable ferous items like a storm anchor, the metal 5-gallon gas tank for the outboard, etc. the tin cans you mentioned, will also have a changing effect. With my autopilot I use it just to keep the boat going in the direction I want but I keep track of what's hapening. I don't use it's magnetic bearing as gospel. Sometimes it's magnetic bearing can be way off but it still steers the course I toggle in. Other times the autopilot just doesn't seem that sensitive and it's probably because of all the ferrous junk I have in it's neighborhood. As an adjunct I have a good Wheems & Plath Venus which is what I'll rely on if things get really tough. P.S. Look out for that heavy steel boat that goes by close abeam! If the fluxgate picks it up it'll steer the boat right for it!
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