Author: elitech_machine

April – 2025

Optimizing Grinding Performance: The Importance of Truing and Dressing

In production grinding applications, achieving optimal performance hinges on using the right truing and dressing tools and applying them effectively. Even when the grinding wheel isn’t perfectly suited for the application, a skilled operator with high-quality dressing tools and techniques can significantly enhance its performance. This ability is especially valuable in shops where maintaining a dedicated wheel for every operation isn’t practical.

Understanding Dressing in Grinding

Dressing is the crucial process of sharpening the abrasive elements of a grinding wheel. Over time, abrasive grains become dull, and the bond holding them in place wears down. Dressing helps by breaking down the bond and removing worn-out grains, thereby exposing fresh, sharp abrasive particles that improve cutting efficiency.

Without proper dressing, it’s impossible to achieve the best consistency and adherence to specs from even the highest quality abrasive wheel. In fact, when you invest in top-quality grinding wheels, it becomes even more important to dress them properly in order to capture the quality and performance benefits.

Beyond sharpening, dressing plays another vital role: it clears out tiny material deposits from the wheel’s pores. If left unchecked, this buildup can lead to wheel loading, which causes unwanted vibration and may result in burn marks on the workpiece. Proper dressing ensures a cleaner, more efficient grinding process and extends the wheel’s lifespan.

The Role of Truing

Truing is another essential aspect of grinding wheel maintenance. Unlike dressing, which focuses on exposing fresh abrasive grains, truing is used to restore the wheel’s shape and concentricity. This process ensures that the wheel runs true to its intended form, eliminating any deviations that could negatively affect precision and surface finish.

Truing is a companion wheel-preparation process performed at the same time as dressing on conventional wheels. With superabrasive wheels, the two processes are accomplished separately, with truing performed first. In superabrasive wheel applications, truing is done with a tool or roll, while dressing often employs a vitrified dressing stick in a secondary operation.

Best Practices for Dressing and Truing

Do’s and Don’ts of Diamond Dressing Tools

Do

1. Back off from the previous feed before inserting a new dresser. Many diamonds are damaged during initial touch-off.
2. Set diamond point at a 10- to 15-degree angle, pointing toward the direction of wheel rotation.
3. Tighten tool solidly in holder without unnecessary tool overhang.
4. Use coolant whenever possible. Flood tool point of contact at all times during dressing.
5. Start dress at the highest point of the wheel, usually the center.
6. Take light cuts. Maximum depth for roughing: 0.001 to 0.002 inch. For finishing: 0.0005 to 0.001 inch.
7. Use the correct traverse rate. The slower the traverse rate, the lower the finish.
8. Dress wheel at regular intervals to prevent loading the surface.
9. Turn tool in holder 1/8 turn in one direction at regular intervals to maintain a sharp point.
10. When diamond wears dull and visibly flat, have it reset or replaced.
11. Get the right carat size diamond for your wheel diameter. Bigger wheels require larger diamonds.

Don’t

1. Don’t hit the wheel with the diamond when placing it in the holder.
2. Don’t set single point tool shank towards the center of the wheel; always offset shank at 10 to 15 degrees.
3. Don’t quench a hot tool; it can crack the diamond. Allow diamonds adequate time to cool between dresses when dressing dry.
4. Don’t assume a wheel is perfectly flat. Look for its highest point for initial contact.
5. Don’t take more than 0.001 inch on wheel radius per dress pass if possible. Excessive infeed can cause premature diamond wear and often fractures the stone.
6. Don’t take too little off the wheel per dress pass. Wheels on older or weaker machines may not clean up.
7. Don’t leave the tool in one position too long. You’ll wear a flat that will glaze the wheel, overheat and damage the stone. Rotate the tool at least once per day.
8. Don’t continue using a worn or damaged tool. Have it reset or replaced.
9. Don’t rough dress at excessive infeed and traverse rates, then slow for finish dressing. This damages the diamond(s). Use the same rates when rough and finish dressing if possible.

Conclusion

The importance of proper truing and dressing cannot be too strongly emphasized. A grinding wheel needs to be trued and dressed before it touches a piece of material. Following these procedures will help ensure that your grinding wheel produces superior results.

Proper truing and dressing techniques are essential for optimizing grinding performance, improving surface finish, and ensuring process efficiency. By equipping operators with the right tools and knowledge, shops can maximize productivity, reduce costs, and maintain high-quality results in their grinding operations. At Elitech Machine Tools, we emphasize the importance of precision in every aspect of grinding, helping businesses achieve superior performance and reliability in their machining processes.

26 March 2025

When performing internal grinding, taper issues are among the most frequently encountered problems. Taper occurs when the bore diameter becomes progressively larger or smaller towards one or both ends, sometimes forming an hourglass or barrel-shaped profile.

Here are six effective solutions to troubleshoot and resolve taper issues:

Solution #1: Change Your Oscillation Stroke

If the bore is smaller on one end, the ends may not be exposed to the grinding wheel enough. Conversely, if the bore is larger at the ends, the center may be receiving excessive grinding. Adjusting the oscillation stroke length can resolve this imbalance.

• Increase Stroke Length: Extend the stroke further into one or both ends to ensure uniform exposure.
• Reduce Stroke Length: Minimize the stroke to reduce grinding at the ends and allow more time in the center.

Refer to the following figure for ID grinding oscillation adjustment tips.

Solution #2: Dress a Reverse Taper into the Wheel

Deflection can occur when the grinding wheel applies pressure, causing the wheel to slightly bend. This misalignment can produce taper in the bore.

• Reverse Dressing: Dress a compensating reverse taper into the wheel to counteract deflection.
• Wheel Inspection: Regularly inspect the wheel’s shape to ensure accuracy.

Solution #3: Increase Spark-Outs

Spark-outs allow time for the wheel to oscillate without feeding, relaxing accumulated forces.

• Extend Spark-Out Time: Add an extra 1-2 seconds to reduce taper by eliminating deflection.
• Monitor Results: Adjust the spark-out duration based on bore quality.

Solution #4: Retract and Regrind

For a faster alternative to extended spark-outs:

• Retract the Wheel: Temporarily pull back to release deflection forces.
• Regrind: Perform a brief regrind cycle for taper correction.

Solution #5: Sharpen the Wheel for Aggressiveness

A dull wheel causes excessive deflection. Sharpening the wheel reduces this effect.

• Aggressive Dressing: Use sharper dressing parameters to maintain wheel sharpness.
• Regular Maintenance: Ensure consistent wheel condition for optimal performance.

Solution #6: Make a Taper Adjustment on Your Machine

Some machines offer taper adjustment through work head or spindle swivel settings.

• CNC Adjustments: Use control settings for quick and precise taper adjustments.
• Manual Adjustments: On older machines, perform mechanical adjustments cautiously to avoid misalignment.

Final Thoughts

While machine adjustments can sometimes solve taper issues, addressing root causes using these best practices is preferable. Elitech Machine Tools recommends starting with oscillation adjustments and spark-outs before considering mechanical interventions. By following these solutions, you can minimize taper problems and achieve optimal grinding results.

17 March 2025

Advancements in CNC turning centers and cutting tools have significantly improved the feasibility of hard turning. However when it comes to precision, cost-effectiveness and process stability, grinding often emerges as the superior choice. At Elitech, we firmly believe that grinding provides better results in many applications.

Elitech is well-known for its Cylindrical OD and ID CNC Grinders, offering cutting-edge solutions for precision grinding. While our expertise extends to both hard turning and grinding, we frequently recommend grinding over hard turning for several key reasons:

1. Superior Surface Finish Tolerance and Roundness

Grinding is unmatched in achieving the highest surface finish standards, holding size tolerance as tight as below 0.010 mm and delivering roundness within 2 microns. Hard turning, while effective, struggles to maintain such consistency across large production runs.

2. Cost-Effective for Hard Materials

Grinding provides a more economical and stable process for materials like ceramic, carbide, which require diamond (PCD or CVD) inserts in turning operations. These inserts wear out quickly, leading to frequent replacements and size variations. In contrast, grinding wheel experience gradual wear and can be dressed to maintain cutting efficiency without stopping production.

3. No Risk of “Lead” on Shaft

A common issue in hard turning is the lead pattern, a spiral texture left by the cutting tool. This surface defect can cause premature seal failures in critical components. Grinding eliminates this issue completely, ensuring a perfectly smooth surface.

4. Grinding Meets Industry Standards

Many industries-including automotive, aerospace, bearing manufacturing – mandate ground finishes for critical components. In such cases, grinding is the only viable option to meet stringent quality requirements.

5. Handles Interrupted Cuts Without Tool Damage

Workpieces with features like keyways or splines create interrupted cuts, which can damage cutting inserts in turning. Grinding wheels, however, are not affected by such interruptions, making them a more reliable choice for complex geometries.

6. Grinding Wheels Offer Better Tool Life & Cost efficiency

A single grinding wheel can last for minimum 10,000 parts before needing replacement, making it significantly more cost-effective than frequently replaced turning inserts.

For example, consider a grinding wheel with a diameter 400 mm and width of 40 mm. The wheel will run until its diameter reaches 300 mm. If 0.010 mm per-piece dressing is applied, the wheel can be changed after 10,000 pieces.

• Grinding Wheel Grade: A60-L5-V10 (commonly used for hardened materials like EN-8, EN-24, EN-31).
• Wheel Cost (Estimate in Year 2025): ₹ 4,000.00
• Cost Per 10,000 Components: ₹ 4,000.00
• Per-Piece Grinding Wheel Cost: ₹ 0.40

Now, compare this with CNC hard part turning:

• CNC Tool Cost (Estimate in Year 2025): ₹ 600.00 per insert
• Tool Change Frequency: After every 50 pieces (angle shift)
• Tool Corners Available: 3 per tool (total 150 pieces per tool)
• Per-Piece Insert Cost: ₹ 4.00

This means that grinding is 10 times more cost-effective than hard turning when considering tooling expenses alone.

7. Minimal Downtime, Maximum Productivity

In CNC lathe, inserts must be frequently changed due to wear, causing production downtime. Grinding wheels, on the other hand, last much longer, reducing machine stoppages and increasing throughput.

Consult the Experts at Elitech

Choosing between hard turning and grinding is not always straightforward. It requires in-depth knowledge of both processes to determine the most efficient and cost-effective approach. At Elitech, our team of experts and technology partners can help you make the right decision based on your specific application.

While we continue to expand awareness of high-performance grinding solutions, our ultimate goal is to maximize your productivity and efficiency. If you are looking for precision, consistency and saving, grinding is the way forward!

For expert consultation and cutting-edge grinding solution, contact Elitech today.

 

16 March 2025

Grinding is a crucial process in manufacturing, particularly when it involves high-value parts that have already undergone significant machining. A Cylindrical Grinder, for example, works on components that have likely been pre-machined on a lathe/CNC turning. If an error occurs during grinding, it could mean scrapping an expensive part, leading to wasted time, materials and machining efforts.

However, the challenge of finding skilled grinding operators is increasing. While skilled machinists are already scarce, experienced grinding specialists are even harder to find. Simultaneously, shrinking lead times and competitive pressures are forcing manufacturers to bring grinding operations in-house rather than relaying on external suppliers. This shift creates a need for efficient, reliable, grinding processes that do not rely on highly skilled operators.

The Role of Automation in Grinding Efficiency

To address the shortage of skilled labor while maintaining high precision and productivity, automation is becoming a key solution. Elitech Machine Tools, a Gujarat, India based manufacturer of production grinding machines, supports companies in implementing automation-driven grinding solutions.

One of the most effective automation techniques in grinding is in-process gauging. While traditionally used as an inspection tool, in-process gauging serves as a productive enhancer in grinding machines. Here’s how:

• Real-Time Monitoring: The gauging system measures the workpiece during the grinding process and sends real-time data to the machine control system.
• Automatic Adjustments: The machine can self-correct based on measurement trends, adjusting for changes in the grinding wheel diameter.
• Extended Wheel Life: Automated adjustment reduce the frequency of wheel dressing, minimize wear and tear, and improving efficiency.
• Consistency And Accuracy: The system maintains tight tolerances with minimal human intervention, reducing error and improving overall product quality.

The Future of Grinding with Limited Skilled Labor

As industries move towards automation, manufacturers that invest in smart grinding technologies can overcome the skilled labor shortage while boosting productivity. Elitech Machine Tools continues to help companies adapt by offering advanced grinding solutions that integrate automation, ensuring reliable and high-precision grinding without the need for expert operators.

By leveraging technology like in-process gauging, manufacturers can safeguard their machining investments, minimize rejections, and optimize grinding efficiency-ultimately making production more cost-effective and competitive.

15 March 2025

Grinding Wheels are essential in metalworking but must be handled, stored and used with care to prevent damage and accidents. Here are key precautions to follow:

1. Proper Storage & Handling

• Store in a dry, temperature-controlled area, away from impacts.
• Inspect new and used wheels for cracks or damage before use.
• Carry wheels carefully-never drop or roll them. Use a hand truck or forklift for heavy wheels.

2. Safe Mounting

• Perform a ‘ring test’ to check for cracks before mounting.
• Ensure the wheel’s center hole fits snugly without forcing it.
• Use clean, flat flanges and tighten the spindle nut just enough to hold the wheel securely.
• Match directional wheels to the correct rotation.

3. Machine & Grinding Safety

• Make sure all guards and covers are in place before starting the machine.
• Let the wheel run at full speed for at least one minute before grinding.
• Never exceed the maximum RPM of the wheel.
• Grind gently-avoid excessive pressure that could cause overheating or brakeage.

4. The Ring Test

• Suspend or place the wheel vertically on a hand surface.
• Tap with a wooden handle 1-2 inches from the edge at a 45 degree angle.
• A clear ring indicates a good wheel; a dull sound may mean cracks.
• Always test before mounting, especially after storage.

Final Tip: Following these precautions ensures safe operation, prolongs wheel life and prevent accidents. Always prioritize safety when using grinding wheels.