[CA] [CA11] Hyraulic linear autopilot choice: Type 2 vs 3

[bstreep]

Chuck,

You previously responded to me that we could install a Type 2. Boat is a Macintosh 47 sailboat, modified keel, 32K displacement per specs, 38K actual. We have a Raymarine 400 autopilot head, and an old hydraulic drive. The Type 3 is just a few hundred $$ more. Does it make sense to step up in size?

Also, we have 29" of room to install, between the centerline, and a bulkhead that runs fore and aft. The Type 3 shows 27.15", plus the part of the mounting foot that extends past the pin (based on the downloaded install sheet). I think I'm ok, but does the end of the ram extend past the mounting foot (the end opposite of the tiller pin)? Or is it completely enclosed within the unit? We have just 5" more than the 29", beyond the bulkhead before we hit the hull. We only need 8" of throw, stop to stop.

Thanks in advance,

Bill Streep
San Antonio, TX

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum Bill,

Q1. Does it make sense to step up in size?
A1. It stands to reason that a hydraulic linear drive of greater capacity than is required will be less strained in operation than one of lower capacity. This would in turn lead to an assumption of greater longevity and reliability. Unlike hydraulic autopilot pumps, which must be chosen in accordance to the capacity of boat's steering ram, hydraulic linear drives are a complete system featuring a pump which is match to the drive's steering ram. It is accordingly acceptable to install a hydraulic linear drive having a greater capacity than is required for the vessel.

Q2. Does the end of the ram of the Type 3 hydraulic linear drive extend past the mounting foot (the end opposite of the tiller pin)? Or is it completely enclosed within the unit?
A2. Negative. The ram is completely enclosed within the drive cylinder.