Centerless grinding machines are often the best choice when parts need to be machined within the shortest timeframe possible. As you can imagine, the operator of these machines has to be very alert, especially when setting the workpiece before starting the operation. This is because the workpiece isn’t secured by a spindle or fixture, but rather two abrasive wheels. Here are some tips from Maximum Advantage-Carolinas on how to effectively use these precision grinding machines.
Accurate Alignment & Positioning of the Regulating Wheel
When you’re aligning the regulating wheel, you should make sure that the diamond truing nib follows the same line of contact with both the wheel and the workpiece. As you do this, you should consider the required angle of the regulating wheel, the center of the workpiece as it relates to the regulating and superabrasive wheels, the swivel angle of the regulating wheel, and the RPM of the regulating wheel (this should be the highest to ensure a smooth surface).
Accurate Alignment & Positioning of the Superabrasive Wheel
This is a very delicate procedure since it ensures that the entire surface of the superabrasive wheel is in use.
Locating the Center of the Workpiece
For efficient machining, the center of the workpiece should be above that of the two grinding wheels (the superabraisve wheel and the regulating wheel). However, the placement shouldn’t be too high since that may cause chatter on the workpiece. Also, it shouldn’t be too low since it may lead to an out-of-round condition on the workpiece.
Setting the Work Rest at the Right Angle
This is important since it reduces the pressure on the grinding wheel, which may cause chatter. The angle of the work rest blade will depend on the width of the superabrasive wheel. For example, for an eight-inch wheel, the best work rest blade angle is 25 degrees. Contrary to what you may think, the angle is smaller for wider wheels and the angle is larger for narrow wheels.
Application of Coolant
You should always make sure that you first choose the correct coolant for the workpiece material you’re machining. The coolant should be applied at the point of contact of the wheel and the workpiece to ensure that there’s no build up of temperatures. High temperature can alter the metallurgical characteristics of the workpiece. This can affect its strength.
To learn more about centerless grinding machines and our other precision grinding machines, call Maximum Advantage-Carolinas.