The Motorsailer Project

Project Log: Saturday, June 2, 2012

With some momentum on the steering system from recent efforts, it seemed like this was the time to continue work and wrap up the main portions of the installation. Specifically, I needed to mount the steering cylinder--or, more accurately, determine what I needed to do to mount it and compete the basic structural steps required.

The after steering room was tight, thanks to the canoe stern, and long ago I'd determined that the required steering cylinder was too long to mount in a purely athwartships or longitudinal manner. To get around this, at an earlier stage of the project I determined I could mount the cylinder at 45°to the boat's centerline, and located a new bronze rudder arm that, with its diamond-shaped shaft hole, fit this need perfectly. I covered these steps, along with basic steering geometry layout, in earlier progress reports.

Even so, the travel required for the steering piston was longer than any available dimension within the steering room and within the limitations imposed by the angle of the rudder arm. So I knew from early on that I'd have to cut an opening in the after cockpit bulkhead to allow appropriate passage of the steering cylinder and piston. This posed no particular concern, since I intended to build new, closed-in cockpit lockers to fill in the spaces left behind by my earlier removal of the original teak-slatted seating surfaces. Whatever opening was required for the steering cylinder would be hidden within the new locker.

Basic measurements and fittings during earlier sessions had given me the idea that I could get away with a simple round hole through the bulkhead, through which the piston end could pass as the rudder turned, so that formed my starting point for the installation. Working off existing layout lines I'd created during the preliminary pre-specification stages of the steering project (more on this presently), I extended some marks to the after bulkhead that represented the general area where I'd need the cut.

The orientation of this photo is forward
and to starboard

Using just the arbor for my hole saw, I drilled through the bulkhead from the aft side to make sure the hole landed in a usable spot on the other side. Then, I drilled a 2" hole through the bulkhead and prepared to do the initial layout of the cylinder. The main goal of all this, eventually, was to determine the requirements, location, and construction of any supports required for the cylinder bracket.

Basic cylinder layout required that the cylinder/piston assembly be mounted so that the cylinder would be aligned through the center points of the steering arm connection pin at the rudder's hard over position in both directions. This was the dark line I'd used to do my initial layout, and earlier I'd created this mark by using measurements provided by the steering manufacturer. To provide full travel of the piston, the instructions called for me to extend the steering piston from the cylinder to a 21" measurement from the center of the bearing support, with the rudder (and rudder arm) centered. Remember throughout the following photos and description that the rudder arm is offset 45° to port when the rudder is centered.

With the cylinder extended as required, I attempted to fit it into position. Immediately there was a problem: with the extended piston, the mounting bracket essentially ended up in the middle of the bulkhead, crushing my dream of a small hole for the passage of the piston. As I struggled with visualizing how this would work, I worried for a time that the required height of the bracket might also mean that I'd have to cut through some of the cockpit sole, which led to further worries of interference with the fuel tank below. After some additional measurements and a few desperate moments, I determined that neither of these issues would come into play, fortunately.

The long and the short of all this was that I had to greatly enlarge my opening through the bulkhead to accommodate the mounting bracket/bearing. So after additional measurements and layout, I marked the four corners of the new opening with 1" holes, and cut the balance with a saw. Later, I even extended the inboard side of the opening by about an inch to better accommodate a large base plate.

With the opening cut, I could finally fit the cylinder in its proposed location. Fortunately, the height of the bottom of the opening, even accounting for a 3/4" base plate, would be appropriate for the cylinder in relation to the height of the steering arm.

The initial layout pointed to the need to extend the opening to port (towards centerline), which I did; then, to prepare ahead for a fiberglass base plate, I ground away the gelcoat from outside the opening, and the paint from inside, and also smoothed the cut edges.

Pay no attention to the orientation of the fittings on the cylinder in these photos, as this does not represent the final orientation of the hose connections and bypass valve; the cylinder rotated freely on the piston, so there was nothing to hold it in one position or another, but I'd orient the fittings in an appropriate way during final installation.

Another note: it's my own doing that the bypass valve/hose kit is installed in the direction it is. Dedicated readers may recall some time ago the issues I had with my own attempt at installing this kit, and Teleflex was nice enough not only to provide me with a replacement cylinder at no cost, but also to pre-install the bypass kit for me. At that time, they had asked me which direction I wished it to face, and I chose the forward direction as it'd seemed the best option based on what I knew. I'd not necessarily anticipated that the cylinder would be so close to the bulkhead, and depending on how I had to align the cylinder fittings the valve itself actually could run into the bulkhead (normal operating position is with the valve closed, or with the handle turned 90° from where its shown in these photos). This would work itself out without major issue, but I was basically stuck with the position it was in.

From a piece of 3/4" G10 epoxy laminate, I prepared a base plate for the steering cylinder's mounting bracket. I chose this material for its excellent strength, since it would form the basis for the entire steering system. Cutting the 8" x 5" piece required for the cylinder mounting left me with an offcut that seemed perfect for the autopilot pump mounting, so I reserved it for that purpose.

After making some layout lines, I test-fit the base plate in the opening and with the cylinder in place. Again, ignore the position of the cylinder hose fittings in most of these photos.

Happy with the basic positioning, I drilled for a single screw to hold the base plate in position for my convenience, and eventually to secure it while I epoxied it in place, since the cantilever of the base plate into the steering room made it unstable.

Relieved of the need to hold the plate constantly, I put the cylinder back in place and, holding the bracket in its appropriate position, moved the rudder (and therefore the cylinder piston) through its full range of motion to check for any issues and, most importantly, to determine that the bracket was in the correct location to allow full travel. Note the changing position of the piston between the photo sets, and how the cylinder and piston are in line with the layout line on the rudder platform when fully extended to each side (which was the desired result).

Hard to Starboard

Hard to Port

That all seemed to work out well, with no binding or interference, and the travel was full and appropriate. Sometime later, I'd add a permanent rudder stop to eliminate the possibility of overtravel when turned hard to starboard.

After cleaning up and solvent-washing, I secured the bracket baseplate with epoxy adhesive and left it for the time being; later I'd add fiberglass tabbing to secure the whole thing. Off to the port side, in a location I'd determined would be convenient, I epoxied in the base plate for the hydraulic autopilot pump after preparing the surface beneath. This base plate was probably not necessary, but with the perfect size offcut on hand, it made sense to install it for additional strength, as well as to raise the pump off the platform a bit.

To wrap up the day's work, I sanded and revarnished the two large bulkheads in the main cabin, as I'd not been happy with the finish of the first coat of satin in these areas.