12
• Environment:
• This drive is not waterproof, so you should mount it in a dry location, clear of any bilge
water.
Mounting bolts
Attach the mounting foot with two stainless steel M12 (
1
/
2
inch) bolts and lock nuts/lock
washers.
Note:
Before finally tightening the bolts you must check sprocket alignment (see page 14) and chain
tension (see page 15).
Note:
Always mount the drive as securely as possible to make sure it performs reliably and the chain
remains correctly aligned.
Connecting to the steering system
The rotary drive is connected to the steering system by a chain drive between a sprocket on
the drive and a sprocket on the boat’s steering shaft.
Note:
Most steering gear manufacturers supply special autopilot drive attachments, and many include
this as standard. Contact your steering gear manufacturer for more information.
When you have checked with the steering gear manufacturer about how and where you can
attach the autopilot chain to the boat’s steering system, you need to:
• determine the sprocket and chain sizes
• attach and align the sprockets and chain
• tension the chain correctly
Determining the sprocket and chain sizes
Chain size
Recommended chain size: standard
3
/
8
inch pitch.
Sprocket sizes
To determine the sprocket sizes required at the steering shaft and rotary drive:
• count the number of times the steering shaft turns when you move the rudder from har-
dover to hardover
• use
Figure 3
to determine the sprocket sizes required at the steering gear shaft (steering
sprocket) and at the rotary drive (drive sprocket) by:
• reading up from the number of steering shaft turns (on the horizontal axis) until you
reach the line for Type 1 or Type 2 drive (as appropriate)
• reading across (to the vertical axis) to identify the appropriate steering and drive
sprocket sizes from the table on the left
• for example, if the steering shaft turns twice when the rudder moves from hardover to
hardover you will need (as indicated by the dotted lines on
Figure 3
):
81174_4.book Page 12 Tuesday, October 29, 2013 11:42 AM
