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E- Replacing The_Claw
When replacing a worn or defective claw, it is
important to rnount the claw correctly before
sceuring the mounting $crews. lncorrect claw
rnountirqg may result in excessive film gate neise
or unsteady picrure.
t. Ccffegrclgrv Pitch
The lnternatbnal dimensiort ol the f6rnm film
Frg. #3O
2- Adiustlng The Claw Pitch
a. Moving th€ fulcrum control assy: The fr.ll-
crum control assy lFig. #all
harizantally
adjusts thc contact point betwe€n the cam
foflouer and the cam which i* turn effects
the claw pitch. Moving the fulcrurn control
assy. to the left decrcases the pitch and
moving it to the right increases the pitch.
oso:o-os
a. The lnternational dimensions of the l6mm
film are shown in Fig, #39. Claw pitch is set
at 7.64 - 7.67mm. A pitch less than 7.64mm
will cause the claw to engage the film between
perforations possibly causing film damage or
unsteady pictures.
b. A pitch more than 7.67mm will cause excessive
gate noise. Typical film perforation should
have a pitch of 7.605 - 7.635mm, but older
films may have a smaller pitch due to shrink-
agF.
c. The claw as shown in {Fig. #40} has a 5
degree angle at the top tooth, and should the
claw pitch become larger than the pitch of the
perforations, this would help prevent any film
damage.
COTSTEOL A,SY
CAM FOLLOTYER
b. The fulcrum control assy. should only be
rnoved slighrly. Tco much adiustment will
cause the claw to hit the sides of the film
perforations causing film jitter.
c. Carrect claw angle is shown in Fig- #42-A-
Under some cirsumitanc*s a bent claw lever
as shown in Fig- #42-B and 42-C may have to
be ccrrected by straightening out lhe claw.
'
Fis' #42
Gf
c!
0
q
Gg
o
+l
q
n|
e
a
o
E
o
o
EI
lt
q
c
+l
F
q
(See Fig. *41)
t . T
S*
Fi8'#48
Fs. #4r
CLAW LEVER
TETTISIOFI SFRING
- l $ '
=df :+ =d
3. Claw Lever Tension
The claw lever tension force should be from 1.2
to 1.25kg when the spring is stretched to the
maximum travel of the elaiy lever arm. lf the
tension is too weak, the cam follawer may float
off rhe cam surface causing excessive gate noise
and an unsteady picture. On the other hand,
if the spring is too strong the cam follower may
wezr ottlt prematurely Ei ealrtft a sligfit hesitation
of the claw lever when the projector is initially
ttarted. To obtain the correEt tension it may be
necessary to replace the spring. A slight adjust-
meni can be made by stretching the spring if
necessary-
- a n -
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