Hints on Mastering the Art of Efficient Projection
Preparing for the Show
Be sure that you are thoroughly familiar with the instructions, threading and operation of the projector. Make sure the circuit to which the equipment is to be connected is adequately fused and that the plugs and sockets are in good condition. Make sure that the correct voltage is applied to the machine in accordance with the instructions (see Connection to Mains Supply). Always stand the projector on a firm support. Keep your cables well away from gangways or other places where there is a danger of members of your audience tripping over them.
Lubricate the projector according to the directions (see Projector Lubrication). Make quite sure that all film contact surfaces are clean and free from deposits of film emulsion. A deposit of hard film emulsion can ruin many reels of film. Never use a metal instrument for removing film emulsion from the contact surfaces – a bone or hard wood scraper will clean without scratching the polished surfaces. Make sure all rollers revolve freely.
Check for bent spools. Allow the projector to run for several minutes before inserting the film to ensure smooth running at constant speed. Whilst the machine is running, test for elevation and required picture size. Check also for cleanliness of the edges of the picture masking. Make sure that the light beam will clear the heads of your audience. A supply of spares is always a wise precaution and should include a projector lamp, pilot lamp and a set of belts. Accessories such as additional lenses, film splicer and re-winder are always useful.
The Show is on
It is unprofessional to show the leader numbers on the screen – the hand is quite an effective mask for this. After focusing, use the lens lock. Remain near the projector throughout the performance in order to make any necessary adjustments. Watch the film and the screen for development of scratch. If a scratch is developing, stop the machine at once, unthread the film from the lower sprocket and trace back until the source of damage is found.
Common causes of scratch are:-
- Dirty picture gate
- Dirty rollers or sticking rollers (causing intermittant scratch)
- Too large or too small a loop (causing film to drag on another part of machine).
Common causes of perforation damage are:-
- Incorrect threading (perforations not registered with sprocket teeth)
- Idler rollers out of alignment
- Fierce take-up
- Damaged sprocket teeth
- Bent spools
(piece omitted about care of Library Films)
Preparation of Projector
The projector reaches you with folded spool arms. Commence by turning the arms fully clockwise into position, making sure that the spring belts are correctly seated in their pulleys and are not crossed. Make sure the take-up belt is seated in the guide pulleys.
The feed spool arm has two belts; that nearest to the arm is the reversing belt (RV), which drives the feed-spool as a take-up when the projector is running in reverse. The outer belt (RW) drives the feed-spool when the projector is being used for rewinding.
The Take-up arm has two pulleys: that nearest to the spool is used for normal running, when the Rewind-Run Lever at rear of Top Arm will be in ‘RUN’ position (i.e. forwards towards spool).
For Rewinding, the Rewind-Run Lever should be moved, with the machine stopped, to REW position. This movement is assisted by slight movement of the Hand Set Knob. The Take-up belt MUST be moved over to the outer Take-up Pulley, and the Motor must be run in forward direction. A convenient method of changing the belt from one pulley to the other is to ‘fold’ the take-up spool arm slightly, this slackens the tension on the belt, which may then be transferred easily.
Preparing to Operate the Projector
Familiarize yourself with the elements of the machine’s construction which you must thoroughly understand if you are to operate it with trouble-free efficiency. A complete study of these instructions is recommended before operating the projector.
Connection to Mains Supply
Operating from 200/250 volts Alternating Current
To operate on 200/250 volts alternating current an 850 watt 200/250 volt to 110 volt transformer is required.
Make sure that the transformer tapping screw is set to correspond with the voltage of the mains supply in use. The transformer is fitted with a voltage selevtor panel carrying two tapping screws. The panel is marked 10-0-200-220-240 volts. One tapping screw must always be in the 0 or 10 volt tapping. When in the 0 tapping the voltage selected is as indicated by the second tapping screw. When in the 10 volt tapping the voltages as selected by the second tapping are increased by 10 volts, i.e. 210-230-250 volts. The life of the lamp can be conserved by utilising a voltage tapping or resistance above that of the mains supply, e.g. mains supply voltage 220, tapping 230. This results in under-running the projector lamp.
In order to make certain of the exact voltage of the mains supply it is advisable to consult the local electrical authority, or if this is not practicable to measure the mains voltage with a voltmeter. It is not sufficient to examine the house meter or a lamp in use and take the presumed voltage from these.
Plug the 200/250 volt side using the mains lead provided, into the wall socket, first making sure that the earthing lead is properly connected to the earth pin in the plug. Plug the 6 ft. lead into the 100 volt socket on the transformer and connect the other end into the projector.
Operating from 110 volt Alternating Current
Connect projector direct to the mains using 25 ft. projector lead.
Operating on 200/250 volts Direct Current
A Model 613 Line Resistance is required, one side of which is connected direct to the mains and earthed as for A.C. operation, the output being connected to the Projector by means of the 6 ft. lead provided. In all cases, the resistance unit tapping must be adjusted to correspond with the voltage of the mains in use.
The Standard Line resistance unit supplied is suitable only for 750 watt projection lamps; it may also be used with A.C. supply.
When the projector is supplied by 200/250 D.C. or A.C. through the normal resistance the 110 volt pilot lamp must be replaced by a 200/250 volt lamp of suitable wattage. The brilliance of a pilot lamp of 200/250 volts used as stated above, will be greatly reduced when the motor is switched on.
Operating on 110 volts Direct Current
The Projector is connected direct to the mains as for A.C. Operation above.
On the base under the motor housing is a switch marked ‘AC’ and ‘DC’. Set the switch for the type of current according to your mains supply. No damage will result if the motor is set for AC when the current is DC, but the speed of the motor will be too great to be controlled by the Speed control. If set for DC when the current is AC, sufficient speed cannot be attained even though the speed control is fully released. Two switches will be found on the rear of the base. The line switch controls the motor, the ‘lamp’ switch controls the projector lamp. The projection lamp will not operate unless the motor is running. The projection lamp should be turned off while rewinding to preserve the life of the lamp.
The pilot lamp is automatically switched on when it is pulled out and automatically turned off when it is pushed back into the housing. This lamp operates independently of the motor or lamp switch. To replace the pilot light bulb, unscrew the guard by turning it counter-clockwise.
Threading and Operation
Be sure that the mains and ‘lamp’ switches are in the off position. Connect the projector to the mains in accordance with the instructions (see Preparing to Operate the Projector). Turn on the line switch and ‘lamp’ switch. With the projector operating and the lamp turned on, loosen the lens locking screw LL, Figure 1, by turning to the left, and slide the lens L forward or backward until the outlines of the frame are sharply defined.
Further to sharpen the focus, revolve the lens first in one direction and then in the other. Lock lens in position by turning the tilt adjustment knob. If the projected image is larger than the screen, move the projector closer. If the image is too small, move the projector farther from the screen. If room size limits the ‘throw’ select the correct lens, as indicated in the table.
If the light on the screen flickers, turn speed control knob 7 counter-clockwise to increase the speed. The proper projection speed for silent films is 16 frames per second or just above the point of noticeable flicker.
Threading the Film
Place the loaded spool on the spindle of the top spool arm. The films should be wound on the spool with the emulsion, or dull, side out (Exception: duplicates from original reversal film, prints of 16 mm. negatives and Kodachrome films are wound and projected with the emulsion side in.) The films should come off the bottom of the spool as shown and the objects on the films should be up-side down as they pass through the projector mechanism. Lead the film above the roller and below the sprocket. Slide the film as far as it will go. Holding the film snugly around the sprocket with the right thumb and index finger, press on the tab to open the guard. Pull gently on the film until the perforations seat on the sprocket teeth. Then release the tab locking the film on the sprocket. Lift the lever upward to open the film gate. Place the film in the channel and form the first loop, following the loop outline on the side of the gear case, being certain that it is fully seated in this channel. Form the second loop, according to the outline on the gear case, and slip the film over the second sprocket. Again press the film as far toward the projector as it will go and, while maintaining correct loop size, lock the film on the sprocket. Close the gate by pressing down the lever as far as it will go. With clutch disengaged turn the hand setting knob several clockwise revolutions. This will engage the film with the claw teeth. Should the lower loop slide upward, continue to turn the hand setting knob until the claw teeth are withdrawn when the film may be pulled down to re-set the loop to the outline on the gear case. It is not possible to move the film downward through the gate unless the claw teeth are withdrawn. Again, test the threading with the hand setting knob. the film should pass over the top of the take-up spool and is held by placing the end of the film in the slot in the hub. The slack in the film should be removed before starting the projector by revolving the take-up spool clockwise.
Before Projecting you should be able to answer “Yes” to the following questions.
- Have you read the preceding instructions?
- Have you cleaned the aperture and optical components?
- Are both loops of the correct size?
- Is the film properly engaged on all sprockets?
- Is the film gate closed?
- Is the film properly started on the take-up spool, with all slack removed?
- Have you tested the threading by turning the hand set knob?
- Have you learned from the ensuing sections of this manual, how to use the clutch, frame, rewind-run lever and reverse-forward switch?
- Is the clutch engaged?
- Is the reverse switch set at ‘Forward’?
- Is the rewind lever at ‘run’ position?
- Is the A.C./D.C. switch correctly set for the mains in use?
Turn on the mains switch, engage the clutch and turn on the lamp. As the first title or picture appears on the screen, carefully revolve the lens, first in one direction and then the other until the title or the picture appears in sharp focus. Lock lens with the screw.
If the picture frame line shows on the screen, turn the framer knob 22 to make the frame line disappear. If the framing moves the picture off the screen, readjust the tilt control.
Still Picture Projection
To project a still picture, the clutch control lever 34 should be pushed back thus disengaging the projector mechanism. If no picture appears on the screen, the closed section of the shutter is obscuring the light. A small movement of the hand setting knob will bring the open section of the shutter into correct position, thus permitting the projection of still pictures. It will be necessary to adjust the lens to focus a still picture. Refocus when motion is resumed.
Always disengage the clutch before changing the film movement direction. The reversing switch 32 is on the rear of the motor housing. By pushing this up to the ‘reverse’ position the film may be reversed at any time during projection.
To rewind the film, lead the end of the film on the lower spool arm to the empty spool on the top arm and fasten to the spool.
On the upper spool arm is the rewind lever. Disengage the clutch and swing the lever from the ‘RUN’ position to ‘REW’ position. Do not force the lever if it does not swing easily, but turn the hand setting knob slightly to disengage the gear.
Move lower take-up belt on to idler pulley which is the pulley farthest away from the take-up arm.
Switch on the motor until it gains speed, then release the clutch, and the film will be rewound rapidly. Immediately after rewinding, and before removing the loaded spool, change the lever to ‘run’ position.
The table of Projected Picture Sizes Obtained with Various Projection Lenses has been captured as a scanned image.
Care and Maintenance of Model 613
Cleaning Optical Parts
Before every show, and at any other time that appears necessary, the projection lens and both condensers should be cleaned. Use lens cleaning tissue. The projection lens is removed merely by pulling it forward by the outer lens barrel. The front and rear elements are then accessible for cleaning.
If only a slight amount of dust has accumulated on these lenses merely use lens cleaning tissue to remove the dust. The greatest care must be taken when cleaning bloomed lenses to avoid scratching or rubbing the surfaces. Dust may be removed with a soft camel-hair brush applied very lightly and carefully or alternatively lens cleaning tissue may be used with equal care. The same treatment should be given the Magnilite condenser, and the main condenser which are removed from the projector by pulling on the holder handles.
Cleaning Film Handling Parts
Preparatory to cleaning the aperture open the film gate, remove the lens, and the removable gate shoe. To remove the gate shoe, grasp the metal and withdraw. Use no tools.
Clean and polish with a soft cloth. If dirt or emulsion has gathered and hardened on the shoe, remove by rubbing with a soft dampened cloth to avoid scratching the polished surface. Use no tools. To clean the aperture insert the brush supplied with the projector through the opening, being careful to stop forward motion of the brush at first sign of contact with the condenser lens. Slowly withdraw brush, turning it in a clockwise and counter-clockwise direction to remove dust and dirt. Clean the film channel by opening the gate and inserting the brush into the channel in a vertical position. With the gate partially closed, move the brush up and down to remove all dirt and emulsion. The machine must not be running. When replacing the gate shoe, be sure that the guides are placed in the grooves formed by the metal plate attached to the back of the lens casing. An audible click will be heard when the metal frame is correctly positioned.
The main oil cup should receive one drop of oil after each 8 hours of operation. The other oil cups should receive one drop of oil after every 32 hours of operation. The sprockets should be saturated with oil every six months. To saturate these felts, have the projector disconnected from the line and lay it on its side. Insert the tip of the oil can into the holes and press the button of the oil can about three times.
“The feed and take-up spool arm spindle bearings require no attention, as they are a special, self-lubricating type.”
Projector Lamp Replacement
To replace the projector lamp, unscrew the cap at the bottom of the lamphouse and allow the lamp to slide out into the hands. It may be necessary for you to tip the projector slightly. If a projector lamp is being replaced during the show, be careful as the lamp slides down to grasp it by the relatively cool centring ring. This operation should be performed quickly since a moment or two after the lamp is disengaged from the socket, the centring ring, acting as a cooling flange, becomes quite warm. If the lamp does not readily drop out, insert the blunt end of a pencil through the top of the lamphouse and rock the lamp until it is dislodged.
Insert the new lamp with the vertical tongue on the centring ring toward the front of the projector and revolve it slightly one way or the other until the tongue settles into the centring slot in the bottom of the lamphouse. Replace the screw cap, making sure that it screws in squarely and tightly to lock the lamp in the proper position.
Before attempting to change a lamp, disconnect the mains lead from the wall socket.
Since the lamps are designed to burn base down, the machine must not be turned upside down, or laid on its side while the lamp is burning.
The reflector is permanently adjusted at the factory and no further adjustments should be attempted. Occasionally it is desirable to polish this reflector in the same manner as the projection lens or the Magnilite condensor. The reflector is removed by turning the holder counter-clockwise. Polish carefully and replace.
Pilot Lamp Replacement
Unscrew the metal cover turnng it counter-clockwise. Unscrew the lamp and replace it with another and put the cover on again.
Motor Brush Replacement
Examine the motor brushes occasionally and replace them when the body wears down to about a quarter of an inch. To replace, remove the two screws MB, which will release the springs to which the brushes are attached. If the brushes are not worn too short to continue using them, clean the ends and replace, being sure that the concave contact surface of each brush is so inserted through the square hole that is will fit the curve of the commutator.
There are three belts fitted to your projector and their functions are as follows:-
- Take-up which is the longest of the three
- Re-wind which is shorter than the take-up belt but of approximately the same diameter
- Reverse which is the shortest belt of the three and of reduced diameter
The replacement of belts should be undertaken as follows:-
Take-up. Thread the belt with a twisting action through the front of the slot in the take-up bracket until the end of the belt comes out of the back of the slot. Fold the take-up arm to shorten the belt path and pass the end of the belt which comes from the front of the slot over the top of the pulley and under the guard. Hook the ends together and close the loops together with a small pair of pliers.
Rewind. Thread the belt with a twisting action through the front of the slot nearest the re-wind/run lever until the end comes out of the rear slot. Fold the upper arm to shorten the belt path. Pass the end of the belt which comes from the rear slot over the top of the re-wind pulley, under the guard, and join as for take-up.
Reverse. Thread the belt with a twisting motion through the short square slot at the front of the projector until the end comes out of the rear slot. Pass the belt over the top of the reverse pulley and under the guard. Join as for take-up.
Do’s and Dont’s
- Oil your projector in accordance with instructions
- Set your AC/DC switch for correct current
- Leave your machine set in the ‘forward’ direction
- Leave your re-wind/run lever in the ‘run’ position
- Make sure your belts are on the correct Pulleys
- Leave your speed control knob unscrewed two or three turns when the show is finished
- Make sure that the lamp lock screw is tight
- Keep all your lenses clean
- Keep all film contact surfaces clean
- Check for bent spools
- Check your voltage
- Move the machine while the lamp is hot
- Clean your projector whilst it is running
- Re-wind or repair a hired film
- Reverse the direction without disengaging the clutch
- Operate run/re-wind lever without disengaging the clutch
- Replace lamps unless mains are diconnected.