Home Movies (1943)

HOME MOVIES FOR NOVEMBER but, like many advanced movie makers, I dreamed of sound in terms of lip-synchronization. And then I set out to make my dream a reality. Briefly, my "dream" consisted of coupling my Eastman 16mm. model EE projector with a dual speed combination turntable and recorder so that recordings could be cut in exact synchronization with the film, and played back on the same apparatus synchronized with the screened picture. Fortunately I began my project while there was still some equipment to be had on the market. I was lucky to find in one radio shop an old 1 6-inch gear-driven turntable. It was sturdy and the mechanism simple. It provided for both 33 1/3 and 78 R.P.M. turntable speeds. And it included a lead screw for the cutting head which operated by means of a worm and pinion gear from the center turntable shaft. It also was fitted with a tachometer which indicated exactly the turntable speed. My problem was to connect this turntable with my projector in such a way that the projector motor would turn both units simultaneously and in synchronization. By counting the number of complete revolutions turned by the main projector shaft for 16 frames, the R.P.M. of the projector was determined. It was decided to couple the turntable to the projector by means of a flexible cable and this involved designing a gear arrangement by which the shaft could be coupled directly to the projector shaft. After determining the gear ratio, a very simple worm drive attachment was built which could be clamped directly in front of the projector shaft by removing the name plate. This is shown at (h) in Fig. 6. By coupling the drive directly to the projector shaft, no strain is placed upon any delicate parts of the projector, as power is derived by belt directly from the motor as may be seen in Fig. 6. By means of a short flexible cable, (Figs. 7 and 8) the projector and turntable virtually become a single unit. The reduction gear ratio is 10 to 1 on the projector take-off coupling. It is unnecessary to drill any holes in the projector to connect this coupling. It is clamped into position by a cross bar (d) as shown in Figs. 6 and 8. A driving. pin (e) is attached to the worm drive shaft. Pushing against this pin is a dowel in the pulley on the projector drive shaft. The pinion shaft (g), Figs. 7 and 8, is square at the base and fits the female connection of the cable (i). The foundation for the gear assembly is lY/'xiY/'x1//' polished boiler plate (h). The pillow blocks (j) and pinion gear (k) is brass, the worm (1) is case hardened steel. These gears were purchased from the Boston Gear Works, Chicago, for less than $3.00. The pinion shaft is made from quarter-inch steel. The flexible cable which is 16 inches in length, is attached to the gear assembly by female collar (m) and to the turntable by means of the male screw (n) . Swinging our attention now to the other unit — the recorderturntable — building up • Fig. 5 — Showing unique idea of mounting recorder and playback arms on phone plugs to facilitate quick removal and interchangeability on turntable. ^2L — »-d 71 8 0cm 7 ffay Sac Chrys-fa/ fict-op pe&e&Mrec etp&Docr/w • Continued on Page 375 • Fig. 4 — Showing details of various alterations necessary to Eastman model EE projector in coupling with turntable and installing auxiliary motor. • Fig. 7 — The unassembled reduction gear coupling which makes possible the, synchronous drive between projector and turntable. • Fig. 8— Another view of reduction gear assembly and flexible cable. The details are explained in the text by author Gray. 357