Motion Picture News (Sept-Oct 1916)

ACCESSORY NEWS SECTION Vol. 14. No. 16 ]SIl©(gllirDfgDfty Projectio Edited by Ira G. Sherman, Past President, Local No. 384, 1. A. T. S. E. Who will answer all questions you may send in, no matter how simple or difficult PROBABLE SOLUTION OF A BAFFLING CARBON TROUBLE Loren Simmons, Princess Theatre, Ottumwa, la.: / am a faithful reader of the News, especially the questions and answers, and certainly get a world of help from them, so in view of the fact that I am having some trouble which baffles me I am seeking your aid. I have a discoloration at my arc very often, my light stays very bright and steady for a few minutes, then it blurs {gets red) and I have to bring the carbons together sharply to again get my light bright. Have tried every kind of carbon, and am at present using % cored speer on top and inch hard in bottom. All seem to give the same results. Am using a Cooper-Hewitt Rectifier outfit. Type A-L. 30 amperes, 60 cycles, 110 volts. Am hooked up on Nos. 3 and 5 posts, 113 volts. Have tested this for grounds or shorts, in fact, have gone over the entire system of wiring but can find nothing that is not right. Have never had this trouble while working in different theatres with a G. E. rectifier. It may seem that I do not watch my light and let the carbons burn too far apart, causing this blur, but I assure you such is not the case. The only time I am away from the machine which is running is when I am threading the other. Answer : I am not familiar with this type of rectifier, therefore am not in a position to answer your question as well as I would like to, nevertheless I will do my best now, and in the meantime will endeavor to familiarize myself with this device and let you know what I discover. It may be that you are not getting the proper combustion with your carbons. If you have tested out as thoroughly as you say and found no trouble with any of the connections it might be advisable to try a soft carbon in the bottom jaw of your lamp for it is quite possible that the hard carbon is what is causing the sputtering. Have you examined the inside of the jaws in the lamp to see that they are perfectly clean and making good contact with the carbon, or it may be that your lamp leads have become so badly corroded that they are in danger of burning off at any minute. This condition might allow you to operate your lamp for some time, but as soon as the resistance became too great the wire would break contact or allow so little current to pass over the break that you would be unable to maintain a steady arc, the bringing together of the carbons, sharply, would again cause the wire to become fused and things would be all right for a few minutes when the entire performance would start all over again. I wish you would let me know if this latter is the solution of your trouble, for as far as I can see there is nothing the matter with your rectifier, and no matter what make of carbons you use the same trouble would be experienced unless your wires were making perfect contact and your lamp, especially the carbon jaws were kept absolutely clean. A MYSTERIOUS "CLICK" IN A POWERS 6-B B. Hugh Mullins, Jacksonville, Texas. — I have been a reader of your department for some time, and wish to compli7nent you on the help you are to operators and their problems. I am operating two Powers machines in the Park theatre here, and on the 6-B machine I have quite a "click." I have cramined the intermittent closely and find that the noise is not there. In fact, I cannot locate just where it is, but it seems to be between the intermittent sprocket and the lower loop. The noise does not seem to harm the machine, but I would like to have the machine run as smooth as possible. Frankly. I am " up a tree " and if you can help me I would appreciate it very much. Wishing you continued success and thanking you in advance for any help you w.ay be to me. Answer : In your first and last paragraphs I was not sure whether it was sarcasm or that you really meant it. I am not egotistical, but if I have been of some assistance to the operator I feel that my efforts have not been in vain, and I thank you for your kind words of appreciation. As to the " click " you mention, it seems to me that the screws that hold the intermittent bushings in place may have become loose, allowing the shaft to become misplaced, which might throw the star too tightly against the cam, which would cause the clicking sound. Have you felt of the cover for the intermittent movement to see that there is no vibration there that might cause the click? Frankly, you have me, too, unless it is possible that the small rollers on the lower film scraper are too close together, preventing the film from following its regular path. If it is, take a light machinist's hammer, and placing a block of wood against each roller in turn, tap gently until there is sufficient room for the film to rest between the rollers. If this does not eliminate the " clicking " write me again, setting forth the nature of the click, and tell me whether there is any unsteadiness of the picture upon the screen, and I may be able to advise you more clearly. SATISFACTORY MOTIOGRAPH PROJECTION Z7 B. HENDRICK, Franklinville, N. Y., writes: Can I get a J—^* satisfactory picture with a Motiograph projector, on a good screen, without a motor generator set; 75 foot throw, picture II feet wide, using 6o cycle A. C. no volt current f Answer : There is no reason in the world why you should not. The improvements that have been made in the late model Motiographs have succeeded in bringing that make machine to the fore, and with a good operator, which is necessary with any make machine, you will find that the Motiograph will give satisfactory service. Of course, you can get good results without a motor-generator set, but better results could be obtained with one, or for that matter, with a rectifier. The saving to you in current bills would soon pay the initial cost of the outfit, for you must remember that double the amperage is required for alternating current than that for direct. But if you are planning to install a reflecting type screen, as I take it you are, you will be able to get very good illumination on the screen with 60 amperes of current, using ^ inch cored carbons top and bottom. May all success attend you in your undertaking, and do not hesitate to call upon me at any time you think I can be of assistance to you. METHOD OF OBTAINING BETTER LIGHT C. Plambeck, Dorchester, Iowa, writes a letter asking for advice as to how to secure a better light. He is operating an engine driven generator, supplying light for commercial purposes as well as for operating his projection machine. Also, wants to know if it will make any difference which vinre goes through the rheostat. Answer. — From a careful reading of your letter I have come to the conclusion that your generator is heavily overloaded, and the only remedy I can suggest would be to install any one of the various types of generators advertised in these columns, which are made by manufacturers, who have designed them for motion picture work exclusively, and which will allow you to increase your amperage to the rated capacity of the machine. As to the rheostat connection, it is generally connected to the positive wire as the current is supposed to flow along that wire and return to the generator by way of the negative wire. I could never see where it made any great difference, but the above is now the accepted way of doing it.