Safety in grinding and cutting operations with abrasive tools Preparation, mounting
and operation of abrasive tool on machine should be performed in accordance with
applicable instructions that include recommendations and requirements of: a manufacturer
of grinding machine, manufacturer of grinding wheel, operation sheets for grinding
operations.
The preparatory and mounting works should be performed by a qualified, trained person
or some other worker under the surveillance of authorized person.
The following checks should be performed before the wheel is mounted on the machine
spindle.
- External appearance: mechanical damages, cracks, scratches, dents, chipping. Such
an inspection is to be carried out under the good lighting
- Perform a sound test Refer to description in the previous Section: Storage
- Check a designation of Cutting wheel and compare the maximum rotational speed
marked on the wheel with the maximum rotational speed of the machine spindle.
Only grinding wheels which have the maximum permissible speed equal or higher than
the actual speed of Spindle may be mounted on the spindle. The maximum permissible
speed marked on the wheel may not be exceeded under no spindle may be mounted on
the spindle. The maximum permissible speed marked on the wheel may not be exceeded
under NO circumstances.
- Check the actual rotational speed of spindle, especially after any repair of cutting machine
- Check condition of locating surfaces for the cutting wheel and clamping faces of flanges that are to:
- Have dimensions to applicable regulations
- Be flat, clean, without defects and should move smoothly without any jamming
- Be square in relation to the datum surfaces
- Clamping flanges are to be paired and have: the same outer diameters, the same recesses and shapes. They should clamp cutting wheels only on ring-shaped faces with the same pressure on both sides. This prevents the cutting wheel to be clamped on the edge of bore which is susceptible to chipping and cracking
- Adaptor flanges must be balanced
- Adaptor of cutting wheel transfers a drive. Make sure that it is correctly located and fixed on the spindle
- Make sure that the cutting wheel fits freely on the spindle or adaptor.
- Proper clamping of nuts and screws of cutting wheel.
The clamping nut should be tightened only sufficiently to ensure that the flanges drive the wheel and prevent slip. Screws on multiple screw type flanges should be tightened gradually and the tightening should proceed from one screw to one diametrically opposite and them in crisscross sequence. Make sure that screws and nuts screw in and out freely without any jamming or resistance.