14
Figure 4: Sprocket bore and keyway dimensions
Attaching drive and steering sprockets
Note:
Each sprocket must be keyed and then screwed to the shaft with a grub screw secured with
thread-locking compound.
Checking sprocket alignment and chain tension
Aligning drive and steering sprockets
Both sprockets must be accurately aligned to run in the same plane when viewed from the
side. Check for correct alignment by holding a straight edge between the edge of the
sprockets (see
Figure 5
).
CAUTION
Drive sprocket
To stop the drive sprocket rotating on the drive shaft, the shaft has a
1
/
8
inch square projection (a woodruff key) that fits into a notch (or keyway)
at the centre of the sprocket. If you use a non-Raymarine drive sprocket,
its bore and keyway dimensions must fall within the ranges specified in
Figure 4
for it to lock correctly to the drive shaft.
9.46 mm – 9.61 mm
(0.3725 in – 0.3785 in)
3.22 mm – 3.24 mm
(0.127 in – 0.1275 in)
15.89 mm – 15.9 mm
(0.6256 in – 0.6275 in)
19 mm
(0.75 in)
12.7 mm
(0.5 in)
grub screw
D5084-1
bore
keyway
81174_4.book Page 14 Tuesday, October 29, 2013 11:42 AM
