Twin City Type ‘E’ Adjustable Pitch Propeller - ES-404 - Manual

Blade Angle Adjustment
Blades are set to the specified blade angle at the fac-
tory. If adjustment in the field is required, use one of
the following two methods:
Preferred Method (more accurate)
1. Lay the hub on a horizontal surface with the concave
(air leaving) surfaces of the blades facing upwards.
2. Loosen the blade retaining bolts until they are finger-
tight. At this point, the blades should rotate in their
sockets when grasped firmly and twisted, but not turn
on their own.
3. Place an angle meter across the two blade angle
position marks on a blade. See Figure 1.
4. Twist the blade to the desired blade angle.
5. Repeat steps 3 and 4 for the remaining blades.
6. Re-tighten the blade retaining bolts to the torque
shown in Table 1. Work in a star pattern, working
your way up to the desired torque in steps. Tightening
one bolt to the full torque before moving on to the
next can crack the hub.
Alternate Method
1. Loosen the blade retaining bolts until they are finger-
tight. At this point, the blades should rotate in their
sockets when grasped firmly and twisted, but not turn
on their own.
2. Angle setting marks on the blade line up with an
indicating arrow on the hub. There are two long marks
on the blade, one for 12° blade angle and another
for 32°. Shorter indicating marks at 5° increments are
in between the two longer marks. See Figure 2 to the
right.
3. Twist each blade to the desired blade angle.
4. Re-tighten the blade retaining bolts to the torque
shown in Table 1. Work in a star pattern, working
your way up to the desired torque in steps. Tightening
one bolt to the full torque before moving on to the
next can crack the hub.
Table 1.
TORQUE (ft. lbs.)
FAN HUB
BUSHING BLADE BUSHING
SIZE DIA.
BOLT BOLT
14 - 24 6" H 17 7.5
30 - 36 9" P 30 13
42 - 48 12" P 75 13
42 - 48 12" Q 75 24
Mounting the Propeller Assembly
on the Shaft
Type ‘E’ propellers are furnished with hubs that have a
tapered bore. A split-tapered bushing is used for mount-
ing the propeller assembly to the shaft. When properly
assembled, the bushing grips the hub and the shaft with
a positive clamping action. See Figure 3 below.
A. The bushing barrel and the bore of the propeller hub
are tapered. This assures concentric mounting and a
true running propeller.
B. The cap screws, when tightened, lock the bushing in
the propeller.
C. The bushing is split so that when the locking cap
screws force the bushing into the tapered bore, the
bushing grips the shaft with a positive clamping fit.
This will withstand vibration and punishing loads
without loosening.
D. The propeller and bushing assembly is keyed to the
shaft and held in place by compression. This gives
added driving strength.
Put the bushing loosely into the propeller. Do not press
or drive. Start the cap screws by hand, turning them
just enough to engage the threads in the tapped holes
on the propeller. Do not use a wrench at this time. The
bushing should be loose enough in the propeller to
move slightly. Be sure the shaft and keyway are clean
and smooth. Check the key size with both the shaft and
bushing keyways. Slide the propeller and bushing
assembly onto the shaft, making allowance for endplay
in the shaft to prevent rubbing. Do not force the propel-
ler and bushing onto the shaft. If it does not go on
easily, check the shaft, bushing, and key sizes.
©2004 Twin City Fan Companies, Ltd.
Figure 1.
Figure 2.
Figure 3.
ES-404
June 2004
Type 'E' Adjustable Pitch Propeller
INSTALLATION, OPERATION & MAINTENANCE MANUAL