China 3 aixs cnc machine high precision cnc machining metal parts manufacturers use different sizes of grinding wheel for machining. The grinding wheel must have a blotter on both sides. Although seemingly unimportant, blotters are a critical safety item and are necessary since they serve as cushions to conform to the minor surface irregularities on the side of the wheel when the wheel is tightened. This reduces the chance of cracking the wheel when it is tightened.
Most pedestal grinders use two thick, precision, washer-like discs called wheel flanges to distribute the clamping force during tightening. Flanges should be the correct size, totally seated against the blotter material, and used on each side of the wheel.
When removing and installing the wheels, it is important to know that most left-side machine spindles have left-handed threads, and right-side machine spindles have right-hand threads so that mounting nuts do not come loose during use. Since a wrench must be used to tighten and remove the nut from the machine spindle, it may be necessary to apply friction with a piece of wood to keep the old wheel from rotating while removing it and for tightening the new wheel. Be careful when tightening the new wheel to apply only enough torque to securely seat the wheel. Consult the machine manual for a torque specification. Be sure to replace and adjust all guards, tool rests, and spark breakers.
Always disconnect power from the machine before removing or installing grinding wheels. When starting a grinder, stand to the side in case the wheel comes apart under the sudden stress of startup, and let the wheel run for one full minute before using to be sure the wheel is safe and does not break.
Tool Rest and Adjustment
Since pedestal grinders are offhand machines, their designers have included a small platform at the face of the wheel to rest the workpiece against during grinding.
This device is called the tool rest. Tool rests help to support the work during grinding and may be set at any desired angle to aid in grinding uniform angled surfaces on the work. After installing the wheel or wheels, adjust the tool rest within 1/16″ of the wheel face.
The space between the tool rest and the wheel should never exceed 1/16″ to prevent parts from china metal custom 4 axis cnc machining high precision micro spare parts manufacturers from being pulled in between the rest and the wheel. As the wheel wears, the space will increase and the rest will need to be adjusted. Always stop the grinder before adjusting the tool rest.
Spark Breaker and Adjustment
Because of the friction created during grinding by precision machining parts suppliers, the very small metal chips have a very high heat concentration. They are usually orange in color due to their temperature and are therefore referred to as “sparks.” Grinding sparks will be extremely hot in the first second or so after their creation and then fizzle out to the natural color of the metal. As the sparks are created, they tend
to wrap around the periphery of the rotating wheel and are often ejected down from the top of the wheel into the area where the operator is holding the workpiece. A device called a spark breaker (sometimes called a spark arrestor) is used to catch and control most of the sparks and to keep them from contacting the operator’s hand.
The spark breaker should be adjusted within 1/16″ of the wheel just like the tool rest. Having the spark breaker properly adjusted can prevent sparks from hitting the user’s hands, and also help contain the wheel in the machine in the event it breaks. This article is from http://www.5axismachiningchina.com