THOUGHTS

Aug 11, 2011
857
O'day 30 313 Georgetown MD
I would like to install the compass and the brains of my new Raymarine Auto Pilot inside the Lazarette on my 30' O'day. I know I'm reaching in there a lot for buckets, cleaning equipment, and all sorts of stuff and I don't want to bump or knock the units. So I've come up with a possible solution. I'm thinking of building a protective box out of pvc board, which will be mounted on the bulkhead that divides the galley and the lazarette. Its would look something like this:

IMG_3229.JPG


It would have no metal interference, it would be installed 3 ft away from and radios or other magnetic fields. Anyone have some thoughts on this?
 
Oct 22, 2014
20,989
CAL 35 Cruiser #21 moored EVERETT WA
The design and basic idea appear sound.

More of a general question. Why the lazarette? Once you install the units you really have no need to touch them or interact with them. Lazarette space is in constant usage and water is splashed or damp things get tossed into the space. This makes space in it valuable for freequent access.

The APU and sensor can be placed in an out of the way location. It should be a dry space not often used.
 
Aug 17, 2010
311
Oday 35 Barrington
In the other thread I posted pictures of my installation on a bulkhead in the far aft of my quarterberth. While the quarterberth is used (mostly for storage), these components are never in the way and are neither bumped nor splashed.
 
Aug 11, 2011
857
O'day 30 313 Georgetown MD
All good stuff. My concerns for the quarter berth area is that I have the ram mike cable for my VHF in that area, there is the TV antenna cable and the secondary VHF antenna cable close by, the Solar power cables are in the same vicinity. A lot going on. I'm afraid of the possibility of too much interference due to any magnetic fields.

I created the "box" anyway, out of scraps I had laying around in my work shop.
IMG_3230.JPG


If I put it in the quarter berth the only thing I'd have to do is to turn the compass 180 degrees.
And when I think about it the power cables will be shorter and the wheel motor cable will have less distance to run. Yep, maybe that is a better idea, thanks.
 
Oct 22, 2014
20,989
CAL 35 Cruiser #21 moored EVERETT WA
The sensor is designed to rotate so you can position the compass inline with the centerline of the boat. Then you identify the position of the sensor in reference to the center of the boat during the commissioning step. The computer, once it knows which way is forward and how far from the center of the boat the sensor is placed, does the heavy lifting for you.
 
Jan 22, 2008
50
Oday 30 Stamford CT
The autopilot instructions state that the autopilot fluxgate compass should be mounted "as far away as possible from large iron masses such as the engine". Mounting the fluxgate compass in the lazarette is not meeting that requirement. I mounted mine on the bulkhead that separates the two compartments under the port side seat cushions.
 
Aug 17, 2010
311
Oday 35 Barrington
I did a delivery in November of 2019. When I went aboard the vessel (a Caliber 40), I placed my PC that runs navigation software at the Nav station, as I was instructed by the vessel owner. This PC uses a GPS "puck" that connects to a USB port and it has a magnetic back for mounting. I placed the puck on top of a metal box (battery monitor, solar controller, or generator switch - I don't remember, and we never used it) that was mounted on the Nav station's aft bulkhead.

Once we got underway the owner and I were baffled when the autopilot wouldn't hold a course. This was an issue because we were counting on the autopilot to hold course on the 20+ hour sail as we passed the New Jersey coast. The owner moved all of his stuff (tools, spares, batteries) out of the forward berth where a fluxgate compass was mounted. He even removed the MAC that he had just mounted on the main saloon bulkhead, yet the autopilot would not hold a course.

On the fifth day of our trip we were at the tip of Sandy Hook, NJ when a Raycor fuel filter clogged, and I went down into the lazerette to change it. Up above my head, on the bulkhead that separates the lazerette from the main cabin, I noticed ANOTHER fluxgate compass was mounted. It seems that this was the fluxgate compass that the autopilot used, and it was 4 inches, and one fiberglass bulkhead away from where I had placed the GPS puck (neither of us had any idea what the second fluxgate compass was for). I moved the puck to another location, and the autopilot was fixed...:cuss:

Don't put your fluxgate in the lazerette.;)
 
Oct 22, 2014
20,989
CAL 35 Cruiser #21 moored EVERETT WA
Here is the EV100 Manual with data for installing the Sensor

Location requirements—EV–1andEV–2
The installation location must take into account the following requirements:
•The unit can be installed above or below decks.
•The unit must be mounted on a horizontal and level surface. The unit may be mounted upright or upside-down, but the unit must be level within 5º of pitch and 5º of roll (compared with the vessel’s neutral position when at rest and normally loaded).
A95E77AC-C3F9-4B47-85DC-07EE97F4A3F9_4_5005_c.jpeg

1. Roll​
2. Pitch​
  • The unit can be mounted on a vertical surface such as a bulkhead or mast etc, using the supplied bracket.
  • The unit location must be at least 1 m (3 ft.) away from any source of magnetic interference, such as compasses and electrical cables.
  • Choose a location where the unit will be safe from physical damage and excessive vibration.
  • Choose a location where the unit will not be subjected to a load or force.
  • Mount away from any source of heat or potential flammable hazards, such as fuel vapor.
  • The unit should be mounted in a location where the diagnostics LED is viewable.
  • The unit must be mounted with the LED ‘arrow’ on the top of the unit pointing towards the vessel’s bow and must be in parallel alignment with the longitudinal axis (centerline) of the vessel.
FC6148AC-004E-4814-9989-7CDF92F8CC8A_4_5005_c.jpeg
1. Vessel’s longitudinal axis.​


Physical damage would mean to me bumped by ferndors being thrown into a locker or lazarette. Or where water could splash on the unit.

Just some thoughts.