Leveling Mr. AutoPilot
Back to Mr. Autopilot
Naturally, Rick has been giving Mr. Autopilot a lot of thought. He goes into the lazarette to sit, look, and think. It comes to him that the ram, while level on one access, may not be level on the correct axis.
This thought begins to grow, he realizes the ram is within 5 degrees in relationship to the angle of the tiller arm located on the rudder post but not with the mounting point under the cockpit footwell. In an ideal situation, these would both be within the same degree of angle.
He tests this theory by unbolting the ram and resting it on a stack of paperback books. Using a level he sees right away there is a several degree error.
Rick emails his thoughts along with a drawing to Jonathan, our tech support guy at Octopus, the hydraulic pump mfg. Jonathan answers right away and agrees this is a good idea. He suggests a slight modification and encourages Rick to follow through with this idea as best we can.
The idea requires 7-inch stainless steel carriage bolts. We have trouble finding them since they are not available here in Mazatlan and the only local alternative is to fabricate them. One quote is about $12 USD per bolt. On a whim we ask Dave, s/v TAMARA, (who is back in the states) if he knows of a source for stainless steel bolts in his area (Portland, Oregon).
Sure enough he does and is willing to pick them up and bring them back with him when they return to Mazatlan in a few weeks. (Not a few minutes or hours as in the states but a few weeks. Do you get the idea of why simple projects often take so long to complete?)
Note: The carriage bolts have a round head. The smooth head is easier on the feet when standing in the cockpit.
This modification requires either longer hydraulic hoses or finding another place to mount the pump, doing so and then rewiring that system. We opt for new hoses. Removing the hoses is a project all in self. The pump and ram are detached and removed from the lazarette along with the hoses The system is drained of hydraulic fluid.
After all that is done, the hoses are taken to a hydraulic shop where they fabricate new hoses (twice as long) with stainless steel connectors. We ask for bronze fittings, but they only have stainless steel. Oh well.
Rick fabricates a wooden block to use as a shim. It is 3-inches thick (the thickest piece of hardwood we could find) and replaces the original shim that was almost 1-inche. In addition, our original measurements indicated another shim would be necessary. It was created out of plywood and encapsulated with epoxy resin to protect it from any possible future delamination. The 7-inch carriage bolts drop through the cockpit foot well and through holes drilled at a slight angle (due to error in the original installation) in the wood shims.
The bronze ram mount is bolted to the wood block shims.
The major requirement is to get the ram mount under the cockpit to be level within 5 degrees, plus or minus. While searching to find a way to convert fractions of an inch to degrees, we found a fellow cruiser with the perfect tool to do the job. Rick is able to get an exact angle by using a “rotating level”. Luckily available from and provided by, Christoph on s/v SHAMU.
The bubble on the right hand side (see photo) turns and is marked in degrees so that it is possible to dial in what you have/need. After some further adjustments, including removing the plywood shim and adjusting the number of shim washers on the tiller arm, we have the degrees down to from 0 to 3 degrees. Well within the 5 degree plus/minus limitation. (Have to have one of those tools “just in case” for the future.)
The whole installation was reassembled and hydraulic fluid added to the system through the cap in the reserve tank. When the system seems to be full, it is necessary to purge the all of the air out of the system.
I stand for hours (it seems) turning the wheel back and forth. Rick is in the lazarette watching for air to bubble up in the reserve tank. Every so often he adds more fluid, one tablespoon at a time. Eventually, all of the air is out of the system.
The autopilot project is almost completed by the end of December, 2010. I say almost completed since the shim and bolts still have to be sealed in place with 5200. That will be done once we are sure it works properly and don’t need to remove anything again. That should be in La Cruz near Puerto Vallarta. Hopefully, with the ram level, the autopilot will function properly.