1、SMPTE RECOMMENDED PRACTICE Dimensions for 8-mm Type S Motion-Picture Projector Reel Spindles RP 50-1 995 Revision of RP 50-1985 1 Scope This practice specifies the dimensions for 8-mm type S motion-picture projector reel spindles. 2 Purpose ANSVSMPTE 160M describes the reels most likely to be used o
2、n 8-mm type S spindles which are the primary items of interchange which must fit onto various projectors. The intent of this practice is to ensure that the primary reel specifications have been adequately considered and will be applied during projector design. 3 Dimensions The dimensions shall be as
3、 given in figure 1 and table 1. The dimensional values stated first (metric) are primary and those stated second (inch) are conver- sions in accordance with IS0 practice. NOTES 1 Use of spindles in 8-mm projection equipment is not necessarily restricted to reels having a vertical plane of rotation.
4、Because horizontally-oriented reels are possible, it is not necessary that the spindle protrude completely through the projection reel. Therefore, a reference di- mension is supplied primarily for use with vertical reels. When horizontal reels are considered, the minimum spin- dle length shall be go
5、verned by the minimum lug protru- sion, dimension B. Page 1 of 2 pages 2 If the manufacturer desires to round, taper, or point the end of the spindle, this may be done at his discretion with any value needed for aesthetic or other design considera- tions. Hence, dimension E is optional. 3 The shape
6、and amount, if any, of the extension of the drive lug beyond dimension B is optional with the manufac- turer, provided that it does not exceed dimensions C and D. 4 A minimum spindle shoulder diameter is provided by dimension G. Good design practice would place any reel- locking device of the spindl
7、e outboard of the width of the projection reel at the spindle hole, possibly forcing the reel against the shoulder. The maximum for dimension G is intentionally less than the minimum diameter of the corre- sponding surface of the reel to allow for runout tolerances of both the spindle and reel and f
8、or a loose fit of the reel on the spindle. 5 A radius is permitted on the drive lug equivalent to half its width in order to allow manufacturers to use a variety of construction methods or materials. The dimension D specified is for a drive lug with no radius (i.e., flat). Any radius (RI) utilized b
9、y the manufacturer may be added to dimension D so the maximum overall span of the spindle plus lug becomes D + RI. 6 The use of three driving lugs spaced approximately 120“ around the spindle is not restricted by this document. How- ever, the width and height tolerances of the lug have not been adeq
10、uately accounted for if such a design is incorpo- rated. If the manufacturer chooses to utilize this approach, he is referred to ANSVSMPTE 160M to ensure adequate fit. Copyright O 1995 by the SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 595 W. Hartsdale Ave., White Plains, NY 10607 (914) 761-1
11、100 Approved January 5,1995 RP 50-1995 SMPTE RPUSO 95 I 8357403 OOOl1824 350 = I I Figure l - Projector reel spindles Table 1 - Specifications A B C D E F G Ri R2 4.0 min 14.0 ref optional 1.40 max 16.00 min 24.50 max 0.7 max 0.20 max f 0.000 - 0.010 0.16 min 0.55 ref + 0.06 - 0.00 optional 0.055 max 0.630 min 0.965 max 0.03 max 0.008 max ) Millimeter dimensions are primary. Annex A (informative) Bibliography ANSI/SMPTE i 60M-1990, Motion-Picture Equipment (8-mm Type S) - Projection Reels - 100- to 31 2-mm Diameter Page 2 of 2 pages
