[C320-list] Raymarine Autopilot

[Greg Arnold]

My boat is the Mk I.

My installation won't work on the initial 320 stern design, which had no
molded-in seats on the swim platform.  With that original design, you
would have to mount the linear drive under the swim step.  However, the
height of the swim step is much too low to work with the design of the
320  rudder post.

Later, Catalina went to molded-in seats on each side of the swim
platform.  I believe this occurred on boats constructed in early 1996,
somewhere in the 366 to 382 range of serial numbers.  The starboard seat
is the perfect height for the autopilot installation, and it also gets
the drive out-of-the-way over the fuel tank.

The problem is that the Raymarine Type 1 drive is too short to reach all
the way from the tiller arm back to the underside of the seats. I solved
this problem by using the RM Type 2 Long linear drive. Another solution
would be to get a piece of (say) 6" x 24" G10 that was maybe 1/4"
thick.  Bolt one end under the swim platform with the other end
extending far enough forward to reach the Type 1 drive.

2005 C320 #1054



On 6/3/2023 4:59 AM, surprise thompson87.com wrote:
> Interesting. When I made the change that was my initial preference but my installer told me the geometry didn’t work for that configuration. Perhaps a difference between the Mark 1 and 2 swim platforms?  Are you Mark 2?
>
>> On Jun 2, 2023, at 8:56 PM, Greg Arnold via C320-list <c320-list at lists.catalina320.com> wrote:
>>
>> I installed a below-deck drive, and have the old ST4000+ control head.
>> The display is a bit faded, but otherwise seems to work fine.  Let me
>> know if you want it.
>>
>> For my below-deck pilot, I went with the Raymarine Type 2 Long linear
>> drive.  Looking at the Defender website, I see the price premium over
>> the Type 1 is now close to $400 -- I could be misremembering, but I
>> thought the premium used to be a lot less.
>>
>> Anyway, the extra length of the Type 2L drive let me bolt it underneath
>> the seat on the starboard swim platform, with the drive extending
>> forward above the fuel tank to the tiller arm on the starboard side of
>> the rudder shaft.
>>
>> Advantages of this arrangement:
>>
>>    The drive is attached to a very study fiberglass part of the boat
>>    Don't need to fabricate any plates
>>    Don't need to cut off the end of the tiller arm (at least for a
>>    rudder that swings 35 degrees to each side, don't know about the
>>    ones that swing to 55 degrees)
>>    Longer tiller arm means you can retain the 55 degree rudder swing if
>>    you have one of the boats with that feature
>>    Can get full range of rudder movement while connecting the drive
>>    toward the end of the tiller arm (9" out on the arm, beyond that
>>    would need to remove some of the vertical ridge on the inboard edge
>>    of the board above the fuel tank)
>>
>> Greg Arnold
>> 2005 C-320 #1054
>> Santa Barbara Harbor, CA
>>
>>
>>
>>