Autopilot installation

[jeff brown]

I'm installing a garmin unit on my 1978 34 marine trader DC.
The technician at Garmin told me the reactor box needs to be near the center line of the boat close to the water line. Also not near any metallic items.
I'm not sure where that would be . The generator and engine are at the center and the bulkhead is in front of that. Has anyone got some ideas?
Thanks!

 

[AKDoug]

I put mine under the bed in the bow. I made the mistake of throwing a scuba cylinder up there once, it made the autopilot very unhappy. There is a lot of storage there, so I just have to remember to not store metallic items nearby. Once in a while I screw up, the autopilot underperforms, and then I remove whatever I placed too near.

 

[Seevee]

reactor box? Is that what Garmin calls their compass? Interesting.

But, yes, you want it reasonably centerline away from metallic objects and lower is better.
Sometimes ya gotta temporarily mount it and check it's performance and perhaps make a few moves before you get it good You'll never get it perfect, nor do you need to. There should be adjustments in your AP controls or compass controls thru the chart plotter to compensate.

I thought I had a perfect spot, down by the washer/dryer... just under the steps going into the staterooms. Nothing metal close that I could see (5 ft or better), center and low. Didn't work. Ended up with it mounted on the "dash" area, way forward at the lower part of the front windows. Not the prettiest but worked. Then tweeted it with the adjustments..... and occasionally tweet again for minor stuff. Doesn't need to be perfect, but needs to be pretty consistent. So, if it's a half degree off when you start a 60 mile trip and still a 1/2 off when you end, you'll be right on. (if you can hold a half degree)

 

[AKDoug]

Also no large wires can pass near near it, my windlass power runs too close to mine and will lock it up when I raise anchor. I just put the MFD in standby when I raise anchor and then bring it back up afterwards. It only locks the compass card up raising, not lowering...

 

[Seevee]

Also no large wires can pass near near it, my windlass power runs too close to mine and will lock it up when I raise anchor. I just put the MFD in standby when I raise anchor and then bring it back up afterwards. It only locks the compass card up raising, not lowering...

AK,

You say "locks" .... like freezes it? Does it "unlock" when you stop the windlass, or do you have to manually unlock it?

 

[jeff brown]

Autopilot

I didn't mention my bow thruster unit and battery is in the bow area under the v berth.
Guess I need a larger boat!

 

[AKDoug]

It locks the magnetic compass from the electrical field at high amp draw, I have to shut off the MFD and restart it to free up the compass. Putting it in standby prevents it from locking up, no idea why it makes the difference between powered up and standby, but it does.

 

[Larry M]

For what it’s worth, I asked several electronic guys before we installed our flux gate compass for the autopilot. A couple suggested to keep it as low and as close to center of the boat that’s practical and to check with a hand held compass for any deviation before permanently mounting. Their rational was lower and centered was for smoother operation. In the rear of Hobo there’s to much metal. They did stress practical.

 

[EngNate]

The reactor contains the fluxgate compass and rate of turn sensor and for best performance should be close to the boat's center of pitch and roll. However, its much more important that it be away from magnetic influences. That means minimum 3 feet from any ferrous material or cables carrying high DC current, 5 feet from things like motors & transformers, and 7 feet from an engine. I have seen pilots perform quite satisfactorily with the compass in various locations all over the boat. The biggest compromise in performance will be from locations high in the boat or far fwd or aft. Give the magnetic rules top priority and make the location as close as practical to the pitch & roll center. I did relocate a GHP10 reactor for a customer who was getting very poor performance. It was a very small boat, 22ft or less, and the only acceptable location was at the helm level, nearly all the way outboard and it worked fine there.

 

[menzies]

My new Simrad one was installed at the bottom of the stairwell to the cabins, under the hatch, and right on top of the holding tank!

Works great. Might stink a bit when it comes to selling it on eBay after any upgrade!