Cruisers Forum

Join CruisersForum Today

Thread Tools Rate Thread Display Modes
Old 12-12-2015, 02:04   #1
Registered User

Join Date: May 2011
Location: Mandurah, Western Australia
Boat: Roberts 57 Staysail Schooner
Posts: 61
Autopilot hydraulic pump - Should I oversize?

Hi all,

I am selecting the components for my autopilot and am most likely going to go with a Raymarine Evolution system. The boat in question is a 57ft full keeler displacing 30,000kg and is steered using 2 Hy-Drive 313 linked in series.

According to the Raymarine site, I only require a little type 1 pump for this setup. They clearly say that displacement does not factor in and only the ram cylinder size matters.

It just seems strange to me that such a big boat can be steered with the same pump as you would find on a 30ft light displacement production boat with a fin keel.

Should I go a size to a type 2 to be safe or am I overthinking this?

pwillems is offline   Reply With Quote
Old 12-12-2015, 08:54   #2
Registered User
stillbuilding's Avatar

Join Date: Jan 2008
Location: Hong Kong
Boat: Custom Freya 20m
Posts: 884
Re: Autopilot hydraulic pump - Should I oversize?

Is probably more about what you have not mentioned - rudder size, degree of balance about the rudder shaft, and of course ram size.

I have a 60' modified long keel with fully unbalanced rudder hung off the aft keel and I need a substantially bigger pump.

Sent from my iPhone using Cruisers Sailing Forums lily hhrn
stillbuilding is offline   Reply With Quote
Old 12-12-2015, 09:05   #3

Join Date: Feb 2013
Location: Boat is on the Rio Dulce
Boat: Seafarer36c
Posts: 3,584
Re: Autopilot hydraulic pump - Should I oversize?

Seems like Raymarine has done the calculations for hyd flow and pressure and say you should be good with the small pump. I've worked on equipment that has 3 cylinders and the pump is no bigger than an apple. My question would be about the response time with the small pump and the big cylinder. Does it need to be slower or faster for a big boat like yours?
Guy is offline   Reply With Quote

autopilot, size

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Oversize Bruce Anchor Jmord Anchoring & Mooring 28 04-09-2015 15:55
Perkins 107/108 oversize rings. Bilge Engines and Propulsion Systems 6 12-01-2012 05:49
For Sale: Hydraulic Pump Autopilot rpu80 S/V_Surya Classifieds Archive 0 19-11-2010 06:40

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 14:37.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.