What is the appearance of the grain on the surface of the workpiece?

- Oct 31, 2019-

During the processing of the grinding machine, there are often lines on the surface of the machined workpiece, which affects the accuracy and affects the appearance. According to experience, there are roughly three cases:


Irregular grain scratches on the surface: This is mainly caused by problems with the grinding fluid and the filtration system, causing particles and abrasive debris falling from the grinding wheel to circulate in the grinding fluid and scratch the surface of the workpiece. At this point the grinding fluid should be replaced or the filter unit added.


There are spirals on the surface for the following reasons:


1. When dressing the grinding wheel, the grinding wheel at the exiting place is convex, and the workpiece is polished to the surface by the bump when the grinding area is out, forming a spiral pattern. The solution is to repair the grinding wheel at the exit or use a file to grind the round side of the grinding wheel.


2. Small cracks appear in the alloy part of the blade that lifts the workpiece, resulting in a surface that is not light and has a pulling phenomenon. Need to sharpen the blade or replace it.


3, the hardness of the bonding agent of the grinding wheel is uneven, resulting in uneven grinding of the grinding wheel. If the sand is still not changed, the grinding wheel needs to be replaced.


4. The feed speed or discharge speed is inconsistent with the normal adjustment of the guide wheel (it is easy to appear in the case of automatic feeding device). Need to adjust the feeding and guide wheel speed feeding.


5. When the guide wheel adjusts the tilt angle and hits R, there is a deviation from the relative position of the axis of the grinding wheel, which needs to be re-aligned.


Oscillation on the surface: mainly due to vibration of the machine itself or oscillation during the grinding of the workpiece.


1. The grinding wheel itself is unstable. It may be that the grinding wheel flange is not clamped correctly, or the dynamic balance is not adjusted. This requires a new installation of the grinding wheel and transfer balance.


2. The bearing in the main shaft is worn or the bearing is improperly adjusted to drive the grinding wheel to vibrate. The bearing clearance should be readjusted or the bearing replaced.


3. The vibration of other equipment is transmitted to the grinding machine and causes resonance. It needs to be away from other vibration sources or digging the anti-vibration groove.


4. Since the bolster supports the blade to increase the center height, the blade is not firmly generated when the workpiece passes. You need to tighten the screws that secure the blade.


5. The grinding wheel spindle is driven by a triangular belt. The length of the V-belt is different or worn, causing machine vibration. Need to check for replacement.


6. The center of the workpiece is too high. The grinding wheel presses the workpiece against the blade by the grinding force. The component force of the guide wheel is reduced, causing uneven force on the workpiece and generating vibration. The center height of the blade should be lowered at this time.


Lemo has over 40 CNC machining centers, include 3 axis,4 axis , 5 axis.

We are expert on Custom metal parts, CNC machined parts, precision machining, aluminum machining, CNC machining ,CNC milling, CNC turning processing, precision grinding and so on. 


 pls conttact us as below :

Amy Chen

Dongguan Lemo Precision Metal Products Co.,Ltd

Direct Phone: 86-137 1326 2409

Skype: amylemo

Email: amy.chen@lemo-machining.com

URL1:www.lemo-machining.com 


Previous:What are the basic requirements for cnc machining commonly used rolling bearings? Next:what kiind of precision level can reach for CNC turning ?