Faulty Sizing

Inconsistent sizing—where workpieces are generally oversize or slightly undersize by a few tenths of a thousandth—is a common challenge. As centreless grinding specialists, we recommend the following procedural adjustments to ensure your centreless grinding machine maintains high-precision tolerances.

Slide Management for Through-Feed Grinding

For the majority of through-feed operations, the stability of the slide is paramount. To prevent microscopic shifts that compromise accuracy:

• Clamping Protocol: Grinding should be performed with the upper slide clamped and the lower slide unclamped.

• Backlash Alignment: The adjusting screw should be set exactly in the middle of the backlash to ensure there is no strain on the screw.

• Environmental Stability: If the infeed screw is under strain, external vibrations—such as a passing industrial truck, a nearby trip hammer, or even a light blow to the machine—can cause a slide movement of a tenth of a thousandth. Likewise, the act of clamping or unclamping a slide can trigger a slight, unwanted movement.

Precision Adjustments

When you need to adjust the slide by only a few tenths of thousandths, do not rely on manual feel alone. Always use a 0.0001″ dial indicator mounted directly against the slide to verify the movement. This level of precision is essential when working with high-performance centreless grinding tools to meet strict UK engineering standards.

Regulating Wheel & Spindle Maintenance

Faulty sizing is frequently traced back to the stability of the regulating wheel.

• Spindle Bearings: Check for loose regulating wheel spindle bearings. These must be adjusted immediately to prevent sizing drift.

• Bearing Recovery: If sizing issues persist after checking all other variables, it may be necessary to scrape the bearings.

• Wheel Condition: Ensure your centreless grinding wheels and regulating wheels are properly dressed using high-quality diamond dressing tools to maintain a consistent contact area.

Optimising Your Setup

Maintaining sizing accuracy requires a holistic approach to machine health. Regularly checking your workrest blades for wear and ensuring your coolant is free from debris with fresh coolant filter paper rolls will help prevent heat-related size fluctuations. For teams looking to master these fine adjustments, we offer specialised centreless grinding training in the UK to help reduce scrap and improve component consistency.