Linear Actuator Load Figures for Autopilot

[aboutgone]

hello all: looking to install a linear actuator for my autopilot. going to try to drive it with a ST4000 head.....how long would the stroke need to be, and what load rating do I need.. I have a CSY 44, 36000# with cable quadrant steering. Any info would be great.....thx Ed

[Paul L]

On the Raymarine site is a manual for the their Linear Driver Installation Guide. It lists specs for displacement, stroke length, hard over time, power, etc.

http://www.raymarine.com/GetFile.asp...5&categoryId=3

This link might get you to it.

[djmarchand]

Aboutgone:

The ST4000 is a wheel pilot, right? You are wanting to use the control head and driver electrics to drive a linear actuator for a 36,000 lb boat?

No way. You will quickly burn out the controls.

David

[aboutgone]

not with a relay.....(A relay is an electrically operated switch. Many relays use an electromagnet to operate a switching mechanism, but other operating principles are also used. Relays find applications where it is necessary to control a circuit by a low-power signal.)...An electrical signal can be used in many application....I know of a guy that's using a st4000 head to operate a CPT wheel pilot, and it uses a heavy duty Bosch truck windshield motor ...after 30,000 miles it's still going strong....it can be done, how much cruising bucks it will take? well that's boating for ya....and hey Paul...thanks for the link..........Ed

[msoneji]

Aboutgone,

I am with David. I would caution and suggest you do proper investigation before you venture in that direction. Talk to Raymarine, they are quite helpful.

The linear drive unit also has the clutch connections that control the clutch mechanism. If you use a relay, you can get a good amount of current to drive the unit, however how are you going to control it without the clutch control? How will the linear drive know when to stop vs. the wheel pilot signals. Note that the linear drive is quite powerful. You need to make sure you don't destroy anything on your steering quadrant. I saw a post somewhere that the linear unit when not installed properly, actually broke the tiller arm right in half! Imagine what it can do to your steering quadrant...Just my two cents.