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Installing the Raymarine SPX-5 Wheel Pilot with P70 Control Head--Part 1

Rating: 9 votes, 5.00 average.
Originally posted on 07-27-2013 (5923 Views)

Joshua Slocumís Spray would sail for hundreds of miles without the captain touching the wheel, but an Ericson 32-3 under power will pirouette like a drunken ballerina if you let go of the helm. Under sail, supervision is also required. So, for shorthanded coastwise work a wheel pilot is the thing to have--inexpensive and easy to install. Or is it?

There are a couple of choices: the somewhat eccentric but robust CPT, and the Raymarine SPX-5 with an advertising budget and a familiar corporate name.

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The coin I flipped came up Raymarine.

The SPX package ships with a new-model control head, the P70. In June, 2013, West Marine quoted $1650, plus $100 California sales tax. I chose Defender, at $1350 with no tax or shipping. The price disparity probably didnít last long.

Wheel pilots hold a compass course, but linked to a modern GPS the SPX-5 can also follow waymarks. How useful this might be is a good question, but I needed a GPS anyhow and chose the Garmin 50s Echomap. The 50s is also new to the market, I learned the hard way.

Ah, electrical work. Itís not my strong point. So, after groping through the fog of Nigel Calder on yacht electrical panels, I opened Theloniousís 28-year ratís nest of mystery wires and floating negative bus bars. The old Combi Instruments looked right off the Star Trek bridge.
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After a few hours I had further identified stone-age Loran, an ancient transducer, multiple obsolete stereo leads and VHS cables and a 12-wire bundle of #18 or #22 wire, many times spliced, that led back to the binnacle. About now you want someone else to take over the whole project. But who? Itís your boat.

Installing a wheel pilot from scratch means location decisions. I wanted the GPS and the P70 control head next to each other on a shelf on the binnacle. But the P70 comes only as a bulkhead mount. That a boat with a wheelpilot probably has a binnacle and that the binnacle puts the helmsman far from any bulkhead apparently did not occur to Raymarine. As I would learn, many things did not occur to Raymarine.

I sketched a custom acrylic box to use a Garmin bracket like that of the GPS. Santa Monica Plastics made it for $140. Both instruments rest on a Star Board and Trex platform backed by a teak cup holder. It works fine. You can also use wood, glue-weld your own plastic, repurpose a 5Ē electrical junction box, have Maine Sail make you one or buy a nav pod for that clunky, expensive look.

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The wires snake inside the rail guard tubing. The rail bases were solid. I drilled through them and the deck. Three holes in the tubes are required: One for the two cables of the Garmin (power/NMEA 0183/ sonar transducer), and on the other tube two more holes Ė for the single cable of the P70 and, lower down, for 12v to the Raymarine motor.

The Garmin 50s can use an in-hull transducer, so no through-hull is needed. West Marine first ordered me the wrong one, but when it arrived corrected its mistake. This unit is glued with Lifeseal to bare fiberglass inside the hull. On my boat it fit nicely next to the original Combi transducer, which now (and forever, probably) is just a sad useless plug in its old through-hull.

The nifty new 30-foot transducer cable, however, has a large connector on it which doesnít snake through holes, and Airmar, the manufacturer for Garmin, recommends strongly that the cable not be cut unless a waterproof junction box is used to rejoin it. I knew immediately that Iíd cut and splice it anyhow, using my questionable skills with butt connectors and kitchen aluminum foil. It worked. Eventually. Hereís all there is to such a cable:
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It would be nice to have a drill press for stainless tubing, but I donít. I put the tube in a wood vise, started with a nail punch, moved up through increasing sizes of drill bits, used lots of cutting oil and drilled slowly so the stainless didnít get hot and harden even harder. Protective paintersí tape over the tubing keeps the rail guard from getting scratched in transit and around the workshop.

I put some on right after I scratched it.

I know, I know Ė weíre not even to the wheel pilot yet. Maybe this isnít a one-weekend project after all?

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  1. Kenneth K's Avatar
    If you do a lot of drilling in tubing, this allows for on-site work.

    Might also be able to fashion a home-made version for a lot less. Or find similar at Harbor Freight?