Building an Autopilot Base

[Paperbird]

I fabricated (and probably over-engineered) a platform for our WH autopilot, but I suspect it is very installation-specific. We have a center cockpit Pearson 422 so the autopilot ram is under the aft bunk. My guess is that you'll have to study your own situation and design to fit. But maybe some of the things I did will help, so I'll try to describe ours a bit.

There is a vertical bulkhead adjacent to where the ram mounts, so I built about a 4"x6" platform out of 3/8" marine ply throughbolted to 1/4" aluminum plate. That was then supported on each end by 3"x4" side plates which were attached to the platform base with 1/4" aluminum angle stock. Then the platform and both side plates were attached to the vertical bulkhead by aluminum angle stock through bolted with a substantial backing plate covering the entire area. I then glassed (bi-ax cloth and resin) the bottom of the platform sides (inside and out) to the hull.

Like I said, probably overkill, but I've read about too many installations coming apart under the stress of the ram working back and forth in heavy seas, which is exactly when I figured we would need it most. Several years of use now with several offshore passages and no movement yet detected. I still check it occasionally during routine maintenance of the steering quadrant or other bits under the bunk.

I have some sketches I can scan and can snap a pic or 2 if you think it might give you some ideas on how to fab yours. Let me know.