Cutting Tool Quality Inspection

Monitoring the quality of the cutting edge of milling cutters and chisels is mostly done through manual labor.
Since the quality of milling cutters and chisels continuously increase the difficulty for human inspection increase too and will be more time consuming.
Vision systems can help to inspect and measure the cutting edge of a milling cutter or chisel very accurate and objectively with high speed.
The measured data is important to improve the current quality level and can be used for very fast process control. The measured data can be used for a measure report or quality certificate.
The required images of the cutting edge as well as the measured damage data can be archived and use for quality improvement purposes or prevent claims. JAIMS Ball Nose cutter type

To determine the feasibility of measuring the sharpness of the cutting edge, a feasibility study over a representative set of ball nose cutters is performed.
This report contains brief the results of the feasibility study and shows the result of a subset of the tested cutters.
The cutters are all new and directly derived from the grinder.
The tested cutters are visual inspected but didn't match the quality level and are rejected. In order to inspect the cutting edge of a cutter, a good image of the edge has to be created which in itself is not trivial, because of the spiral shape. The optics depth of field and an appropriate lighting to create a good image of the curved cutter edge is challenging.

Damaged and not sharp cutting edge

To show the possibilities of vision to measure the cutting edge the bad parts or damages (reason to reject the cutter) of 3 cutters are shown in this report.

JAIMS Color img cutting tool JAIMS Color sub img cutting tool

Cutting tool number 1

Color image left and the subimage on the right visualizes the damaged cutting edge.
Total image size is about 4mm in horizontal direction and 3 mm vertically.
For reliable detection followed by an accurate measurement a monochrome camera gives a better result because of a higher resolution. JAIMS sub image 01 JAIMS Graph sub image 01

Due of very high contrast (line profile) a reliable detection of the damaged edge is possible.
After a detection the geometrical dimensions of the damage is measured. The width of the damage in image above is 11 μm and the length 295 μm.

Cutting tool number 2

Left subimage shows a large but thin damage at the cutting edge of a rejected cutter.

The right subimage shows the detected edges and the measured width (in pixels) of the damaged part is graphically represented under both images.
Scaling: =1.4 μm /pixel vertical and 7 μm/pixel horizontal.

JAIMS sub image 02 JAIMS sub image incl edges 02 JAIMS Graph measured points sub image 02


Cutting tool number 3

Even when the damage exceeds the 'linear' part of the ball nose cutter a reliable detection followed by an accurate measurement is performed.
The width of this damage is 6.6 μm over a length of ~1680 μm.

JAIMS sub image 03 JAIMS sub image incl edges 03 JAIMS Graph measured points sub image 03
For more detailed information about Needle Tip Quality Inspection download the pdf: Cutting Tool Quality Inspection.pdf