Movie Makers (Jan-Dec 1952)

12 MAKING THAT SPLICE A. C. KADOW THE task of making good splices is often a discouraging one for the movie maker. For they tend to break when insufficient or old cement is used. Conversely, when too much cement is used, splices curl with age and bounce the projector gate as they pass through the machine, causing the screen image to move in and out of focus. Further, frames become smudged with excess cement and transparent lines are caused by uncontrolled scraping. These are just a few of the many problems encountered. Having experienced most of these difficulties, I decided to see what could be done with existing equipment to make a better splice. The splicer at hand was the popular Griswold Junior which normally creates a splice .10 of an inch wide. My first move was to remove the anvil ( or scraping surface) and grind it down to .05 inch thickness. This would make possible a splice exactly the width of the sprocket holes. This grinding job will be one for a machine shop and should not cost too much. It will be necessary afterward to use .025 inch shims on each side of tbe anvil to relocate it in the center of the anvil mounting slots. While doing this, remove the scraper guide rod. The next job was to remove the pressure springs A and B ( see Fig. 1 ) . Examination will show that the film-contact surfaces are slightly rounded. File these surfaces until a fiat surface is obtained across the full thickness of the spring. A very fine file should be used, and the surfaces then smoothed on an oil stone, or you may use crocus cloth. Now we are ready to mount the springs. We will use only the top spring on the left side, and both springs on the right side. Mount the left spring so it will just rest on the anvil, about .003 to .004 of an inch, or just enough to hold the film in place on the anvil. Be sure it is mounted perfectly square so that your emulsion scraping will be square with the film. Now mount the two right hand springs. The top spring must come down snugly beside the left hand spring and both of the right hand springs should rest completely on the anvil when the pressure plate is down. (I 3000 OHM -10 WATT RESISTOR TOII5V HOUSE CURRENT V ~7 — THIS SPRING RESTS ON ANVIL .003" OR .004" \f at PRESSURE SPRINGS -ANVIL h.05 c c SCRAPER CORNERS MUST BE SQUARE TO WORK -I CLOSE TO LEFT PRESSURE II i "^SPRING >: How an ingenious amateur revamped an already able splicer — even to installing a heating unit FIG. 1: Essentials of the author's adaptations to the Griswold splicer are diagrammed above: thinner anvil, new scraper, and an electric heating unit. The thickness of these two springs just about equals the width of the splice and thus will apply pressure over the entire surface when properly adjusted. The adjustment of these pressure springs is very important and should be carefully done. The next step is to readjust the shearing blades so that they will cut off the film properly. Be sure that they fit squarely against the anvil so as to make a clean cut. Next we must make a new scraper. But do not discard the Griswold scraper since the stiff brush on it is very good for brushing away the loose emulsion. Our new scraper has a handle made of a % inch wood dowel, or better still a plastic rod. Cut a slot in one end and insert a piece of hacksaw blade (see Fig. 1). Grind the edges and end perfectly square, dress the end and edges with an oil stone, and you have a scraper which is easy to handle and recondition whenever it becomes worn. The next addition to our splicer is an electric anvil heater. The heater element is a 3000 ohm, 10 watt resistor, which can be obtained at a radio store. This resistor when connected across the 115 volt house lighting circuit will keep the anvil temperature at about 120 to 130 degrees Fahrenheit, which is sufficiently high to evaporate the moisture from the film base and will also speed up the setting of the film cement. Figs. 1 and 2 will show the assembly of this heater unit. The resistor is mounted in the bracket and fastened with a long, threaded rod through the center of the [Continued on page 24] FIG. 2: At left the anvil heating unit, with cover removed, is seen in place on bottom of the splicer. FIG. 3: A flick of cement on the tips of upper film is recommended by author.