International projectionist (Jan-Dec 1935)

12 INTERNATIONAL PROJECTIONIST yet the motor armature still heats badly, look for troubles in the motor itself. Bearings may be too tight or may need oil, or the oil rings may not be working. Dirt may be wedged in the housing, between the poles, or in the air gap. Does the commutator or ring look burnt in places? See if the brushes rise and fall slightly when the armature is rotated slowly. The commutator or ring may be "out-of-round." Are any wearing down faster than others? Are the mica insulation divisions between the commutator bars projecting slightly above the metal? If the mica has been "undercut" below the level of the bars to avoid this trouble, the slots may have been filled up with dirt, dust or oil. Is the metal of the rings softer in some parts than in others? Are rings or commutator "gummy" or dirty? Short-Circuited Winding Coil Bad sparking and flashing, combined with only part of the armature getting hot, suggest a short-circuited coil in the winding. The same symptoms, but with all parts of the armature equally hot, suggest unequal air-gaps between poles and armature; or between stator and rotor in an a. c. machine. In both types of mot r the current will rise; and in an a. c. induction motor (g nerally used in mills and factories) this current will be unequal in the different phase winding. The usual cause of the trouble is, of course, worn bearings; but another cause may be that the poles were originally adjusted to final air-gap accuracy by means of thin shims placed at the back of the poles, and that in reassembling these have been omitted or have slipped out when the poles were bolted up in place. Bad contacts or broken wires between coils and commutator show up by violent flashing at the broken points (often becoming a ring of flame around the commutator) though there may be little heating in the windings in general. Speed and Load Considerations If the speed of a d. c. motor is too high on no load, and the machine also refuses to start under load and blows its fuse, a weak field is indicated. If recently disassembled, there may be a reversed field connection, a partial shortcircuit in one or more field coils, or trouble in the starter. In an a. c. induction motor, look for a short-circuit or break in one of the phase windings of the rotor or stator. In an induction motor, however, the no load speed will not be too high (wound rotor type motor). Before checking the phase windings, see if one fuse is blown. A blown fuse may allow an already-started polyphase motor to continue to run on the other phases, but at a high current. Note that if one field in a d. c. motor be short-circuited, the resultant electrical unbalance will cause sparking on the set of brushes under its influence. Sparking troubles due to grounds are not included, mainly because the only way to detect them far enough ahead is by proper measuring instruments in the hands of a skilled repairman. .Also, when a "ground" has got to the stage where it is obvious to ordinary inspection, it is generally too late to do much about it. Sharp Division of Craft Opinion on I. P. Print Footage Publication r I ' HAT there exists a sharp division of -* opinion among projectionists as to the desirability of publishing footage numbers in these columns is disclosed by the deluge of opinions received in answer to our query of last month. Many and varied are the reasons advanced in support of both sides of the question. The most important objection voiced by those on the negative side of the discussion is that footage figures as released by the distributors are invariably incorrect, several readers citing variances as great as ten minutes. Then there is the question of censorship cuts which in some states render worse than useless any published figures. Typical opinions follow: I am opposed to I. P. printing film footages. Such figures as are now published in exhibitor trade journals are as much as ten minutes off in many cases. I am thinking, too, of all the I. P. space these footages would require, to no good purpose. Let's all follow the suggestion made by Max Bentzman in your April issue which, if followed by the craft, would be much better and would save the space in I. P. for the more important material you are now presenting. C. T. Johnson Lockport, N. Y. I am a projectionist in a third-run house and have to do a lot of guessing about footages. I recommend publication of feature footages, at least, in I. P. Roy Beal Fort Wayne, Indiana Register me as emphatically opposed to publication of footage figures in I. P. Correct figures would be impossible to obtain and would only cause more confusion. S. Cooley Manchester, N. H. Mr. Bentzman suggested that, prior to shipment, all projectionists mark the footage numbers, as they found them, on the reel bands of all subjects, II May 1935 features and shorts. Objection to this suggestion has been voiced on the ground that if the reels are returned to exchanges before reaching the subsequent-run theatre, there is small chance that the markings, even if they are not obliterated, will be correct. Other representative opinions follow: I think that publication of running time in I. P. is a great idea. The running times now published in other papers (which seldom reach the projection room, anyhow) are always incorrect and lead us all astray. I have to estimate the running time on all subjects coming in, and as we use a double-feature program, the difficulties are apparent. The ideal system, of course, would be for the exchanges to clock footages after each run, and then to mark the footage plainly on the band before the next shipment. But will they? I think not. This Local will gladly cooperate with you and the field in any plan adopted. Dean W. Morehouse Secretary, Local 338 Watertown, N. Y. . .. . We should like to cast our vote as a unit in favor of I. P. printing the footage lengths of current features and short subj ects. Ernest E. Cassin Secretary, Local 622 Port Huron, Mich. Probably the most desirable way of solving this problem is to work it out not on a national but on a state-wide basis. The clue to such a plan is contained in the following interesting communication which not only presents a very worth while idea but also reveals the existence of that which most readers consider impossible to attain — cooperation with other state units: Knowing that exchanges have done nothing to date in marking running times on features and short subject reel bands, the undersigned and Mr. Francis Hill, projectionist of the Florida Theatre here, have had made to our order a rubber stamp which we use on all releases — features, shorts, news, etc. The stamp reads as follows : Running Time Minutes Pheil Theatre, St. Petersburg, Fla. FERNANDEZ & BARHYDT, Projectionists I.A.T.S.E. 552 We have succeeded in interesting several other Florida Locals in the plan, and it is working out fine, with almost every shpw that comes in now having distinct footage markings on the bands. I don't know whether we projectionists are running ahead of ourselves in this matter, as I still believe that this is" a job for the exchanges. In view of exchange delinquency, however, we Florida projectionists have followed the aforementioned routine, and it has helped tremendously. As for the censorship angle mentioned in' I. P., once the Florida State Board has passed a given picture there is nothing to worry about from this angle. The running time as marked on the bands works (Continued on next page, Col. 1)