1、 1 Scope The dimensions shown in this standard are for double 8-mm type R motion-picture film spools with a nominal capacity of 100 ft (30 m). These spools are used in cameras of the type in which each roll of film is passed through the camera twice for exposure in accordance with SMPTE 231. The spi
2、ndle holes in the spool are shown with splines which are intended to assist in ensuring correct orientation of the spool in the camera. 2 Dimensions 2.1 The dimensions shall be as given in figures 1 through 4 and table 1. 2.2 If rivet heads or other fastening devices extend beyond the outer surfaces
3、 of the flanges, they shall lie at a larger diameter than the minimum K diameter and within the boundaries defined by other portions of the volume of rotation diagram (see figure 1). 2.3 Dimension H2is the space between the flanges inside the core, but outside the D-diameter zone. 2.4 Dimension H3ap
4、plies within a diameter of 0.38 in (9.7 mm) centered on the spindle hole of each flange. 2.5 Dimension J represents the thickness of the spool within the K-diameter area, which is centered on the spindle hole axis of each flange. 2.6 A reference plane of rotation for each flange is defined by a plan
5、e perpendicular to the axis of the spindle and coincident with the surface of a flat, 0.615-in (15.62-mm) diameter support, which is in contact with the flange and centered on the spindle hole axis of the flange. Dimension P is the distance measured outwardly from the reference plane of rotation to
6、the farthest plane of rotation described by any point on the flange outside the K-diameter zone when the spool is rotated on an accurate, tight-fitting spindle. This includes rivets or other fastening devices, variations in flange thickness, flatness, and lateral runout of the flanges. (The referenc
7、e plane from which P is measured is not necessarily coincident with all points within the K-diameter zone, but only with those which are in contact with the reference support which has a diameter smaller than K.) Selection of a value for dimension P is dependent upon the thickness of the material us
8、ed for the flanges. According to the flange material thickness, (1) the K-diameter area may be depressed (with P greater than zero), or (2) the outside surfaces of the flanges may be flat from the spindle hole area to the periphery (with P equal to zero), or (3) in the case of flanges made of very t
9、hin material, the K-diameter area may be raised rather than recessed (effectively, P less than zero). 2.7 The maximum effective thickness of spools (including all the characteristics mentioned in 2.6) outside the K-diameter area has not been stated because it is a function of a spools specific J val
10、ue between the 0.615-in (15.62-mm) diameter reference zones on each flange. The largest overall effective thickness, however, will be J max + 2P max = 0.77 in (19.6 mm). Page 1 of 5 pages SMPTE 173-2004 Revision of SMPTE 173-1999 Copyright 2004 by THE SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEE
11、RS 595 W. Hartsdale Ave., White Plains, NY 10607 (914) 761-1100 Approved November 8, 2004 SMPTE STANDARD for Motion-Picture Equipment (8-mm Type R) Double 8-mm Camera Spools 100-Ft Capacity SMPTE 173-2004 Page 2 of 5 pages Figure 1 Flanges, sectional view and volume of rotation Figure 2 Enlarged vie
12、w of splined holes SMPTE 173-2004 Page 3 of 5 pages Figure 3 Enlarged section for dimension N1Figure 4 Spindle and spool relationships SMPTE 173-2004 Page 4 of 5 pages Table 1 Specifications Dimensions Inches Millimeters C 0.287 + 0.008 0.000 7.29 + 0.20 0.00 D 0.384 min 9.75 min E (See 2.9) 0.750 0
13、.015 19.05 0.38 F 0.035 0.020 0.89 0.51 H10.632 + 0.014 0.000 16.05 + 0.36 0.00 H20.630 min 16.00 min H30.622 min 15.80 min J 0.73 + 0.00 0.02 18.5 + 0.0 0.5 K 0.615 min 15.62 min M 3.62 + 0.00 0.04 91.9 + 0.0 1.0 N10.038 min 0.97 min N20.025 min 0.64 min P (See 2.6) 0.020 max 0.51 max Degrees 20 +
14、0 1 90 120 2.8 The eccentricity of the core with respect to the spindle hole axis should not exceed a total radius variation (total indicator reading) of 0.03 in (0.8 mm). 2.9 A dimension of 1.26 in 0.02 in (32.0 mm 0.5 mm) should be considered for the diameter of the core. All future design should
15、be directed toward this dimension to aid in the design of metering devices. 2.10 When thin material is used for flanges, annexes A.3 and A.4 should be taken into account. 2.11 Dimension F (figure 1) specifies the width of the slot in the core for attaching the end of the film. NOTES 1 When the loade
16、d camera is viewed from the side, with the lens to the left, and the bottom of the housing downward (regardless of whether or not the spool-loading mechanism is visible from that side), both the supply and the take-up spools rotate in a clockwise direction. 2 Flanges should be opaque and their surfa
17、ces should have low-reflectance characteristics. 3 Spool capacity is based on a film thickness of approximately 0.006 in (0.15 mm). SMPTE 173-2004 Page 5 of 5 pages Annex A (informative) Additional data A.1 It is expected that every spool manufacturer will hold H1within the narrowest limits that his
18、 design and manufacturing process permits. A.2 Camera spindles should allow for a radius of not more than 0.015 in (0.38 mm) at each corner of each tongue. A.3 Figures 3 and 4 represent special examples of how the needs of certain dimensions critical to proper performance in some cameras can be met
19、by appropriate shaping or embossing of the spool stock if spools are made of a thin-gage material (much less than 0.040 in 1.02 mm). For a number of years, the effective thickness of the four-spindled webs which engage most camera drivers, dimension N1, was the stock thickness, nominally 0.040 in (1
20、.02 mm). Recently, spools have been made from thinner materials which required embossing to maintain dimension J in order to enable the splines to engage the camera drivers, some of which have a clearance approaching 0.025 in (0.64 mm). Dimension N1normally is measured to a flat support having a dia
21、meter of 0.615 in (15.62 mm). Many cameras have spool support washers with diameters considerably less than 0.615 in (15.62 mm). In order to ensure proper operation with such cameras, the dimension from the inside of the four-spindled flange to the plane of a flat support 0.395 in (10.03 mm) in diam
22、eter centered on the spindle hole axis of the flange, dimension N2(figure 4), shall be at least 0.025 in (0.64 mm). The enlarged section for dimension N1(figure 3) illustrates one method of shaping the splines in the four-splined flange so they will engage the camera driving spindle when the flange
23、thickness is less than 0.025 in (0.64 mm). A.4 Camera spindles engaging the four-splined flange of the spool should not have a gap greater than 0.010 in (0.25 mm) between the bottom of the spindle driving spline and the top of the spindle shoulder or washer that supports the spool. It is recommended
24、 that, in newly designed cameras, the diameter of the supporting spindle shoulder or washer be not less than 0.500 in (12.70 mm) and no greater than 0.615 in (15.62 mm). A.5 To facilitate the distinction between a roll of film which has been exposed along only the first side (one-half width) and a r
25、oll of film which has not been exposed at all or has been exposed along both the first and second sides (both one-half widths), it is recommended that the flanges of spools be marked prominently as follows: Raw stock spools Camera accessory spools Numeral Numeral and/or phrase Flange with four- 1 2
26、No phrase (or numeral) splined spindle hole necessary if phrase shown below is included on other flange. Flange with three- Phrase or equivalent as follows: splined spindle hole Film on this spool is half exposed. Attention is called to the fact that if a camera accessory spool wound with the first
27、exposure run of film is removed from the camera, identification of the film exposure status is more obvious if the spool has been marked with a phrase instead of (or in addition to) numerals. Some camera accessory spools have identical four-splined holes in each flange. (Supply spindles of such came
28、ras have one small lug or none.) Both flanges of such accessory spools should be marked with the phrase suggested above. To ensure proper orientation for the second exposure in this case, in addition to the phrase, it is helpful to have the numeral 1 on one flange and the numeral 2 on the other. A.6
29、 Neither this standard nor SMPTE 231 restricts the perforation type of double-perforated 8-mm film that can be supplied with the spools. Generally, these spools are used only with conventional 8-mm motion-picture films; i.e., those cut and perforated 16-mm 2R-1500. Double super 8 motion-picture film
30、s (16-mm 2R-1664 or 1667) are usually supplied on 16-mm camera spools having square spindle holes aligned as specified in ANSI/SMPTE 174. Annex B (informative) Bibliography ANSI/SMPTE 174-1994 (R2003), Motion-Picture Equipment (16-mm) Camera Spools 50- to 400-Ft Capacity SMPTE 231-2004, Motion-Picture Film (8-mm Type R) Camera Aperture Image and Usage
