Below deck autopilot install

LogoFreak · September 30, 2021, 09:12:56 PM

More staring today, but I got a game plan so time wasn't wasted. Where the manual bilge pump is attached there's been a leak for many many years and all the core in that area has dry rotted.

What I'm going to do is remove the manual bilge pump and remove all the rotten plywood till I get to glass, I'll do that in the vertical and the floor area as well. Once I'm down to solid core I think I'll just rebuild in pure glass and integrate the mount for the ram into that, I don't think I'll have strength issues that way.

I also marked exactly where the center is, then where 30° and 35° is. Took a few pictures but not sure it's very visible, marked with a sharpie.

KeelsonGraham · October 23, 2021, 06:41:00 AM

Quote from: Noah on September 28, 2021, 07:37:49 PM
Logo- I think you have already seen my install and I know a MKI is different, but you might consider the "tower" mount to the hull as an alternative option.

Hey Noah, how did you bond your tower to the hull? I see four bolts and I read that you glassed a 1.5" oak panel onto the hull. Did you simply put the nuts into some kind of rebated hole on the hull side of the oak panel? If so, how did you make certain that they can't/won't ever turn?

Noah · October 23, 2021, 10:19:17 AM

My original install 6 years ago was done poorly by an "experienced" guy I hired. I was not yet retired at the time, and I did not supervise job adequately. The original tower was made out of plywood and West System resin. While the shape of the tower itself was designed semi-OK, it was only bonded to the hull with fibers and resin and not bonded nor encapsulated in fiberglass. After five years, while sailing on autopilot offshore the whole thing suffered a catastrophic collapse. The autopilot "quit" and manual steering was severely limited. Once safely anchored, I removed bulkheads and water tank and discovered the tower had detached from the hull, with the ram still attached to the radial drive/quadrant. The whole thing was dragging around in the bilge. Turns out the plywood on the tower had spilt between layers of ply at its base, with one layer still glued to the hull. The ram was OK albeit spewed some hydraulic fluid as it was being dragged flipped around in the bilge—but thankfully no other boat damage.

Mount #2
A: Prepping the Hull
First step was to strengthen the hull around designated mounting position: I did this by fiberglassing 7x 7 x 1-1/2 in. thick White Oak block to the hull encapsulated in 7 layers of 1708 biaxial fiberglass cloth and West System resin. The wood block was shaped/tapered to the correct angle to match the hull (using angle grinder, and chisel and sandpaper) prior to glassing. The entire landing pad area was appropriately expanded past the wood block using glass to about 14 x14 in. to help spread the loads across a larger area of the hull. I may have gone "overboard" on this, but my ram develops 750 lbs of thrust and I didn't want any more system failures in the future.

B: The New Mounting Tower
I designed this and had it welded/machined by an excellent local fabricator. Primary brief was; "it had to be bulletproof and easily removable and reinstall-able to allow access to cockpit drain hoses, bilge pump hoses and aft hull thru-hull if/when required."
The tower/mount is all stainless steel and built in two pieces. Piece #1 is a 3/8 in. thick flat plate that is permanently attached to the hull—using eight (#14) 1-1/2 in. flathead machine screws bedded with West System epoxy. The plate is also bedded in thickened epoxy.
The screws are countersunk into plate to make a smooth surface upon which to mount the tower. The plate also has 7 threaded holes (5/16 in.) to bolt the tower to the plate.

The Tower: the tower is also 3/8 in. stainless steel. It bolts onto the plate with (7) 5/16 hex-head bolts using blue loctite. The ram pivot base (1/4 stainless steel-which is part of the ram) bolts onto the tower using (4) 5/16 in. bolts and nylock nuts.

All is working well—so far. I can also attest to its ease of removability, as i just did that to replace my cockpit drains and a bilge hose. All went smoothly.

Noah · October 23, 2021, 10:20:01 AM

Final install:

KeelsonGraham · October 23, 2021, 01:27:28 PM

Thank you Noah. That's an extremely useful description.

waughoo · October 23, 2021, 10:06:09 PM

Sure do love seeing that installation Noah. It is absolutely beautiful!

LogoFreak · October 24, 2021, 09:24:41 AM

Nice Jon Noah! Interesting that there's a lot more of your rudder shaft exposed below the quadrant, I would have mounted my tiller below as well if I could.

LogoFreak · March 18, 2022, 07:28:12 PM

Question to those who have an evolution autopilot installed on their C34's.

Where did you mount the EV1 sensor? and is it behaving, as in how much interference is there in your particular chosen location?

waughoo · March 18, 2022, 07:43:46 PM

I put mine below the galley sink slightly above the opening door at the hot water tank. It is mounted on the 45° diagonal part of the galley liner (inside the cabinet in case that is unclear). My goal was to try and get it as close to the center of the moment of effort in all three axis. I haven't used it much at all so I can't say much to your second question. I used a magnectic interference app that showed that spot to be just fine.

Gregory M · March 19, 2022, 04:46:06 AM

aft cabin, no issues

LogoFreak · March 20, 2022, 11:06:03 PM

Thanks guys! Much appreciated. Alex you're the second person that I've heard mounting it there, will give that a shot.

waughoo · March 21, 2022, 09:14:50 AM

Let me know if you want to see any photos. It is hard to get a good one based on where it is, but I can do my best if you think it will help.

haydenwse · March 21, 2022, 07:35:40 PM

Quote from: LogoFreak on March 18, 2022, 07:28:12 PM
Question to those who have an evolution autopilot installed on their C34's.

Where did you mount the EV1 sensor? and is it behaving, as in how much interference is there in your particular chosen location?

If you have not mounted your EV1 yet, you might download the Gemeco iNstall app from the Play store or Appstore. It turns your smart phone into a very sensitive magnetometer. I found it very useful and have been completely happy with my location.
https://play.google.com/store/apps/details?id=net.sailracer.gemecoinstall

LogoFreak · March 21, 2022, 08:43:57 PM

Quote from: waughoo on March 21, 2022, 09:14:50 AM
Let me know if you want to see any photos. It is hard to get a good one based on where it is, but I can do my best if you think it will help.

Did you have to remove the sink in order to mount the EV-1? I guessing you epoxied a piece of ply to screw the mount to?

waughoo · March 21, 2022, 09:27:51 PM

Sink stayed in place. I mounted a pice of ply in there to screw into. It was a tricky place to work, but I love that I can't see it. I also used the iNstall app as suggested above. It helped to confirm I was okay to mount it there. I got it as close as I could in line with the boats direction of travel and then adjusted it out on the water when there wasnt tide or wind to effect direction of travel. The final adjustments to heading I will make in the software.