Bell & Howell - Projector - Filmosound 641 - 642 ... - Cine Information

When adjusting Design 642 projectors,
it will be necessary to
remove the two screws (43) and
permit the clutch stop (44) and
bracket (45) to drop to expose the
screws (30).
(a) To lengthen the stroke, move
the shuttle arm plate (33,
Figure 12) toward the pulldown
cam.
(b) To shorten the stroke, move
the shuttle arm plate assembly
away from the pull-down
cam.
(c) After adjusting the stroke,
recheck the shuttle tooth side
clearance as instructed in
paragraph 43a, and readjust
if necessary.
Caution - Do not attempt to eliminate film
slap by setting the stroke outside the
established tolerances. This will produce
double image and/or jump with Elms having
different shrink or stretch.
F. Framing Adjustment
Thread the projector with film having
a proper frame line position. Project the
film and turn the framing knob from one
limit to the other. If at one limit a
frame-line is not visible, loosen the nut on
framing eccentric, located at the top of
the shuttle arm plate assembly (33*, Figure
12) and turn the eccentric until the frame -
line appears. Hold the eccentric while
tightening the nut. Check the adjustment
by again turning the framing knob from
limit to limit while observing the picture.
When the eccentric is properly adjusted,
either frame-line can be projected and
movement of the film should be approximately
equal at the top and bottom of the
framer travel.
44. SPROCKET SHOE ADJUSTMENT
Loosen the two screws which hold the
34
sprocket shoe assembly to the mechanism.
Place two thicknesses of film on the
sprocket and close the shoe. Lightly
press the shoe against the film and shift
the shoe sideways, if required, to ensure
full and even bearing of the shoe against
the film. Tighten the retaining screws.
Note - If the shde does not bear evenly
against the film through the whole contact
area, jamming at splices or pull-through
(with 100 foot reels) may be encountered.
45. LENS MOUNT ADJUSTMENT
Angular relationship between the projection
lens mount and aperture plate is
controlled by the lens mount stop screw
(19, Figure 11). Thread the projector
with roll title or target film having sharp
images in the corners and project a picture
approximately 30 inches high onto a matt
surface.
Note - The projector must be square with
the screen. Focus the picture and compare
the resolution of the two sides of the image
when viewed from a distance of approximately
twice the width of the picture. If
one side appears to be soft, refocus to
sharpen that edge of the picture and note
whether the lens is moved toward or away
from the aperture. For example, if the
image at the right hand edge of the screen
is soft until the lens is moved toward the
aperture, then the lens stop screw is set
too far forward and should be turned
clockwise.
Caution - This adjustment is critical. The
lens stop screw should be turned only a
few degrees between tests for sharpness.
46. ANIMATION CLUTCH ADJUSTMENTS
(Design 642 only)
A. Clearance Between Stop Pawl and
Trigger
Correct clearance between the stop
pawl (39, Figure 12) and trigger (29, Figure
13) is 0.010 to 0.015 inch. Adjust by
loosening the screws (43, Figure 12) and