|
Installation
Instructions
The
Autoprop is supplied fully assembled, tested, and ready to fit to
your yacht. Observing the following instructions and notes will
ensure correct fitting and trouble free service.
Make
a note of the AP number marked on the blades of your propeller.
This is a serial number that will have all specifications of your
propeller, hub, engine etc.
Tools required for installation/removal and maintenance
Selection of Allen keys (metric)
Small flat blade screwdriver
Socket wrench and/or adjustable wrench
Propeller puller
Autoprop specific puller available
Installation
Before installing your new Autoprop ensure that the cutlass bearing
is not worn. A worn bearing will not be suitable for any propeller.
If it is worn, replace it with a good quality bearing
preferably
with a brass shell casing.
1.
After removing the old propeller check that the shaft taper, key
and thread are undamaged. Try the new shaft nut on the shaft thread.
The shaft taper should be clean and dry. Check that the key will
slide through the Autoprop keyway without jamming at any point.
2.
Slide the Autoprop onto the shaft (without the key in place). Mark
the shaft at the forward edge of the Autoprop hub. Remove the Autoprop
and place the key into the shaft keyway. Slide the Autoprop back
onto the shaft and check that the forward edge of the hub comes
to your shaft mark. If it does not then it is likely that the key
is too large, and the Autoprop is not seated to the shaft correctly.
Remove the Autoprop and file the top of the key down until the Autoprop
will slide on to the shaft and reach the mark. This will ensure
that the Autoprop is now correctly seated to the shaft taper.
3.
Screw the new shaft nut up tight on to the shaft. In some cases
the flat on the nut will be positioned so that the locking screw
will tighten directly to the flat. If the locking screw hits on
the barrel of the nut then it will be necessary to dimple the shaft
nut with either a drill or punch. (See Figure 1 for examples).
4.
Smear the threads of the locking screw with thread locking compound
and screw it down on to the shaft nut.
5.
Re-install the anode nose cone on the aft end of the propeller hub.
The
installation is now complete and the Autoprop is ready for use.
Removal
1.
We recommend that you use the Autoprop puller or similar when removing
the propeller. This puller is simple to use and avoids having to
remove the rope cutter if fitted. Most three legged prop pullers
will also work with the Autoprop.
2.
Remove the anode nose cone by removing the three nylon screws.
3.
Unscrew the shaft nut locking screw until it is clear of the shaft
nut.
4.
Unscrew the shaft hut.
5.
You can now use the puller to remove the Autoprop from the shaft.
If using the Autoprop puller attach the plate to the aft end of
the propeller hub using the three threaded holes for the anode.
Screw in the center-jacking bolt until the propeller hub loosens
on the shaft taper. Remove the propeller.
6.
Tape the key to the shaft or remove and keep in a safe place. Generally
the key is supplied with the shaft
not with the propeller.
Maintenance
Your
new Autoprop is fitted with greasing channels in each of the blades.
Therefore blade removal is not necessary in order to re-grease the
propeller bearings.
The Autoprop should be re-greased once every two years or if more
convenient during your annual haul out.
The
Autoprop needs good protection from electrolytic and chemical corrosion.
Ensure that you replace the anode when ever necessary. Early dissolving
of the anode could be an indication of an electrical problem within
the boat.
For additional protection it is advisable to have a shaft anode,
as the Autoprop anode will only protect the propeller.
While
in the water the Autoprop should be cleaned so as to obtain optimum
performance when motoring. Heavy fouling of an Autoprop (or any
propeller) will reduce the propeller's performance. With heavy fouling
there will be a loss of thrust and also a reduction in the maximum
engine RPM attainable. (This will also happen with a standard propeller.)
The Autoprop will still self-pitch correctly.
In areas of high fouling, smoothly coating the Autoprop with a high
quality marine antifouling may help reduce the growth.
Whenever
you haul-out for antifouling or laying-up for example, the Autoprop
should be given a power wash, before it dries out. This will remove
any deposits or growth from the propeller. After this rotate the
blades by hand to ensure that they move freely.
If you are leaving the boat out for a longtime it is recommended
that you re-grease the bearings at this time.
Greasing the Bearings
There
are two 5mm stainless steel pan head screws in each blade. One in
the center of the blade bearing cap, the other in the base of the
blade. Both are fitted with "O" rings. The one in the
center is the grease exit hole. The one in the base of the blade
is for inserting the grease. Both will be removed during the re-grease
operation.
A
special grease fitting is supplied with every propeller. This fitting
will attach to a standard grease gun hose end fitting.
Only
use the recommended grease or one with the same specifications or
better. Two recommended greases are SKF LGWA 2.0/4 or CRC #SL-3110,
New Generation.
Procedure:
1. Using a 3mm Allen key remove the two pan head screws.
2.
Screw the custom grease fitting into the channel on the side of
the blade.
3.
The blade can now be filled with new grease. Pump the gun until
new grease pushed up out through the exit hole in the center of
the blade. Rotate the blade to ensure all of the old grease has
been removed.
4.
Clean any excess grease from the retaining cap and replace the pan
head screw and "O" ring.
5.
Remove the grease fitting from the side of the blade and replace
the pan head screw and "O" ring.
6.
Ensure that all three blades have been done and that all pan head
screws have been re-installed.
Bearing replacement
Being
a mechanical product there will come a time when the bearings will
need to be replaced. This is a straightforward procedure. It is
not necessary to have the propeller sent back to Autoprop to have
the bearings replaced. Any good facility will be able to do this.
Full instructions are supplied with the bearing replacement kit.
To order this kit, simply contact your Autoprop distributor with
the AP serial number. They will know the correct kit to supply.
Additional Information:
Automatic
Variable Pitch
The Autoprps blades are custom designed for the particular power,
shaft RPM and speed of your yacht. The components of hydrodynamic
force (boat speed), and centrifugal force (SRPM) balance, to set
the blades at the correct pitch angle. As the yacht speed or the
engine revolutions change, the blades will automatically re-adjust
to keep the optimum pitch angle to the waterflow. This gives a high
thrust and efficiency over a wide range of conditions.
Feathering
your Autoprop under sail
All you need to do is to stop the engine while motoring in ahead,
this will feather the blades. Now leave your engine engaged in ahead.
This applies to mechanical transmissions.
If your transmission is hydraulic you will need to have either a
shaft brake or shaft lock.
Maneuvering
Characteristics
Due to the self-pitching action of the Autoprop, maneuvering is
different to a conventional propeller. Firstly, in most every case,
there is noticeably less prop-walk experienced. This is due to the
finer pitch setting at low speeds giving a reduced "paddle
wheel" effect. Secondly, in reverse the blade shape is exactly
the same as in forward. Thirdly, due to the finer pitch, at low
speeds there is less "bite" felt when engaging ahead or
astern from a standstill. This means that more engine Rpms than
normal should be used when moving off from a standstill, or at very
low speeds. Once some speed has been attained, the engine Rpms can
be reduced.
This
unique feature of the Autoprop enables the full power of the engine
to be used in situations such as towing, or in emergencies. With
conventional or feathering propellers, the pitch is too coarse at
very low speeds, the engine cannot achieve its full Rpms, and therefore
full thrust is not achieved.
Damaging
your Autoprop
The Autoprop is some 40% stronger than conventional propellers,
as it is made from a special high-grade bronze alloy called Superston.
The high resistance to impact damage means that you are less likely
to damage the Autoprop blades. In the unlikely event that a blade
becomes damaged, you only need to replace that blade, and not the
complete propeller.
Fitting
a rope cutter
You may fit a rope cutter with an Autoprop in the same way as any
other propeller.
|