Raymarine rudder reference sensor on a MK1

ewengstrom · February 10, 2022, 07:50:45 AM

I've looked thru the two recent posts about installing the Raymarine M81105 rudder position sensor on both the Mk1.5 and the Mk2 but haven't found anything specifically for the Mk1 (with the aft water tank)...so here goes.
Those two posts have me pretty excited with the hope of improving the performance of our EV1 autopilot. But our 1988 seems to present its own issues with fitting the unit to the quadrant. Does anyone have any pics of their install specifically on the MK1 with the aft water tank?
I need to pull things apart and really look at it but based on the pics I took during the initial refit two years ago...I don't have a lot of room to work with. There is a factory support there to support the propane locker. (rotten place for that thing....but that's a project for another time). This support blocks access to the entire top of the quadrant....which is where it appears most attach the arm from the sensor.
Any pics from someone who's figured this out already will be greatly appreciated.

waughoo · February 10, 2022, 08:54:10 AM

Yikes!! That is indeed a very unfortunate location for that support. You might need to build a mount location and then make a relief cut in the propane support leg to allow for clearance of the rudder reference arm and linkage.

ewengstrom · February 11, 2022, 02:55:51 AM

My thoughts exactly Alex. I'll be pulling the aft cabin apart tomorrow in preparation of this install.
Part of the reason I posted this thread is to help others in this situation since I didn't see it out there already. If I get lucky and someone posts how they did it I won't have to reinvent the wheel. Either way I plan to follow up and report how this works out.

waughoo · February 11, 2022, 09:32:28 AM

I am wondering if perhaps installing longer bolts on the rudder limit post on the aft end of the radial wheel and attaching your sender to the aft lower side of the radial wheel will allow for a less annoying install. If you have seen the way I did mine, it would basically be the same but off the back and below the radial wheel instead of over. The water tank might present a bit of a challenge, but maybe?

ewengstrom · March 21, 2022, 04:20:52 AM

Post install follow up!!!! Installation of the rudder sensor was actually easier than I first thought, I did end up pulling the aft water tank as it was just much easier than working around it.
I did have to remove and rip down the starboard propane locker support to approximately the same depth as the 4x4 quadrant stop it attaches to. This gave me enough clearance for the arm to work correctly between the sensor and the quadrant. It's depth is now 3-1/4" rather than the 5" (+,-) it once was. I was able to fabricate a mount for the quadrant exactly like Alex used on his 1.5 (many thanks Alex, SUPER design). It's a 5/16" piece of fiberglass I had from the fabrication on my windlass mount I made a few years ago. It's really overkill for this application....but it was "free" and just sitting there....
To mount the sensor itself I used a piece of aluminum angle material screwed directly into the new propane locker support.
Mounting the sensor at the front of the quadrant over the water tank keeps it well protected and away from items just tossed into the aft storage compartment. (It'll happen....eventually)
I'm still finishing up a few other winter projects so I haven't had the opportunity to test the unit yet, but given the reports from others I have high hopes for some much improved performance of our Raymarine EV100!!!

waughoo · March 21, 2022, 09:13:26 AM

Shazam!!! Nice looking install. Having that wood available to screw your aluminum bracket to certainly makes the install a lot less labor intesive. I am now onto glassing in a battery tray for a start battery under the aft cabin. I thought I was done with glassi g for a while :-/

Ron Hill · March 21, 2022, 01:38:54 PM

Eric : On the MK 1 with a standard transom, I found it easy to place a vertical white stripe on the emergency tiller cap when the rudder is amidships. Then all I do is look down at that strip and I know the rudder position!! Found it unnecessary to ever need a rudder sensor instrument.

A thought

Stu Jackson · March 21, 2022, 01:46:27 PM

Quote from: Ron Hill on March 21, 2022, 01:38:54 PM
Eric : On the MK 1 with a standard transom, I found it easy to place a vertical white stripe on the emergency tiller cap when the rudder is amidships. Then all I do is look down at that strip and I know the rudder position!! Found it unnecessary to ever need a rudder sensor instrument.

Ron, as I understand it,, this discussion has to do with a rudder position sensor for the electronics, which can't simply look down between its legs.

I didn't even bother with a stripe on the cap it's got a honkin' big hole in the front that I can see clearly even with my degenerating eyesight.

Actually, I find that rudder cap one of the handiest bits of detail in my cockpit; it's a superb rudder position reference, far better than anything anyone's hung on their wheel. That and the slopes on the cockpit sole outboard of the helmsman standing position.

Ron Hill · March 21, 2022, 02:04:46 PM

Stu : I agree, but put the strip on the tiller cap so it is easier to see by others than myself (at the helm) also I made 3 wraps of 1/8" nylon line on either side of the wheel's amidships spoke so you and also feel the rudder position!!

A thought

ewengstrom · March 22, 2022, 03:32:26 AM

Stu is correct, the issue wasn't me peeking down between my toes to see where my rudder is pointed, this install is meant to provide said info to the autopilot and help it control the wandering it seems to enjoy by not having this info. This condition doesn't seem to happen all the time but this brand new Raymarine unit wanders much more than my old Navico WP30 did (at 20+ years old) on my last boat. The very fact that Raymarine offers it seems to indicate that it is needed to assist the autopilot.....and it really wasn't all that expensive so I'm giving it a shot.
BTW, I did wrap my wheel this winter with black nylon seine twine and put a turks head knot at the topmost position of the wheel so I know when the rudder is centered. I don't even have to look at the wheel to know when it's centered.
I do like that rudder cap on the MK-1 though, but mostly when I'm backing the boat into a slip, I'll peek down to be sure it's centered and then lock it so the rudder won't just take off and make my docking procedure look like less of a controlled crash than it already is.
I do plan to report back on the addition of this rudder position sensor and whether there is a noticeable improvement in performance this year over last. Hopefully this will help others decide one way or another whether to spend the time and money and what to expect when installing it on a MK-1 if they do.