Richardson's handbook of projection (1927)

HANDBOOK OF PROJECTION FOR Sprockets in Line How may you determine whether or no all the sprockets are exactly in line with each other and with the aperture ? 630, 631 Adjustment of Intermittent Movement NOTE — In the text you are advised that the intermittent sprocket should have a^ trifle of circumferential play. This is not really 'true. With modern projectors there should be none at all, but we feel it is dangerous for any but the experienced projectionist to undertake so fine an adjustment, therefore we have not altered the text from that which applied to projectors years ago, in which an adjustment eliminating such play entirely, usually meant a "freezing" up of the movement. Adjustment When Cold What should be considered if intermittent adjustment is made while the projector is cold?.... 631 Should fine adjustment be made if movement is worn ? 632 Spare Movement Is it advisable and true economy to carry a spare projector intermittent movement in stock in the theatre ? .••••.•••. 632 Should the projectionist attempt to replace a cam or star? 632 Never Try It Should the projectionist attempt to install a new star with an old cam, or vice versa ? 632 Describe the process of installing a new intermittent sprocket 633 End Play Should the intermittent sprocket have end play? 634 May worn sprocket pin holes cause end play? 634 Worn Intermittent Sprocket Teeth Should an intermittent sprocket be used after its teeth are appreciably worn ? 635 In what way and how often should sprocket teeth be ' examined ? '. 635 Name some of the trouble and damage caused by worn intermittent sprocket teeth 635 Do intermittent sprocket teeth perform very heavy duty? 635 viii