Document 3JMbEq4Ybpn8d5n3o3v3DoKOx

Machine Tools TABLE 26-E MINIMUM DIMENSIONS FOR TAPERED SAFETY FLANGES FOR WHEELS OPERATING BETWEEN 6500 AND 9500 PERIPHERAL FEET PER MINUTE Wheel Diam (in) Wheel Thick ness (in ) B (in) C Max On) Mm (in ) D (in) E (in ) J. K (in ) (in) L (in) M (in ) N (in ) 16 4 10 VO 1 *0 Vs 6 Vh Vs VlS Vs 18 4 12 2 Vh Vs 7/a 62 Vs Vs Vs 20 4 14 3 2 1 1 7 2'U 1 Vis Vs 24 4 18 4 3 VO 1V4 83 IV2 Vis Vs 30 4 24 5 3'/2 VO IV2 10 4 2 Vs Vs NOTE Flanges made to these dimensions are extremely large and heavy, and it is not practical to use them on ordinary floor stand gnnders For the larger sizes, it is usually advisable to use outboard beanngs flanges Blotting paper not more than 0 025 m thick or rubber or leather compression washers not more than 0 125 m thick may be used for this purpose If flanges with babbitt or lead facings are used, the thickness of the facing should not exceed 0 125 in and the diameter of washers, regardless of the mate rial, should not be less than the diameter of the flange Allowance for the mounting fit of the wheel should be made m the wheel hole rather than in the arbor or wheel mount (Fig 26-14) The wheel should not be forced on the spin dle, because such forcing may loosen or other wise damage the wheel bushing or crack the wheel A wheel that is too loose on the spin dle will run off-center Table 26-F gives minimum spindle diameters Spindle end nuts should hold the wheel firmly but not too tightly Too much pressure may spring or distort the flange or may even break the wheel If rebushing is necessary to make the wheel fit the spindle, the job should be done by the manufacturer, or in the plant by an experi enced man with suitable equipment Immediately after mounting the wheel and before turning on the power, the operator should turn the wheel by hand for a few revo lutions to see that it clears both the work rest and the hood guard Disk mountings Abrasive disks of the inserted nut, inserted washer, and projecting stud types are mounted on steel disk wheels (machine face plates) approximately the same diameter as the wheel The diameter of the disk determines the minimum thickness of the steel disk wheel upon which it is mounted (Table 26-G) Figs 26-15, 26-16, and 26-17 dem onstrate the differences between the three types of mountings The screw holes m the machine face plate are located to match the threaded holes m the inserted nuts in the wheel The holes should be large enough so the screws will not bind The screws for the inserted nut type should have square ends, be threaded clear to the end, and engage all the threads in the inserted nuts Under no circumstances should the screws be so long that the end of the screw touches the bottom of the hole of the inserted nut Plate mounted wheels usually need a steel disk wheel (machine face plate) to reinforce the steel mounting plate provided when man- 766