Burrs and other foreign objects on datum surfaces induce fixture wear and locating inaccuracies. Here, locating pin basics regarding how to avoid the negative effects of burrs and foreign matter.

Countermeasures against burrs and foreign matter

There are following three methods of avoiding inaccuracies induced by burrs, chips, and foreign matter.

1. Use of datum feature designs easy to clean.
2. Self cleaning design where location action cleans automatically.
3. Employing designs that avoid negative effects by burrs and foreign matter.

In the following, a) will firstly be explained.

a) Use of datum feature designs easy to clean. (see [Fig.1])

Explanation

Use the following viewpoints to design for easy to clean datum features.

• Select small wear resistant locating pins to make for easy to clean designs.
• Avoid hard to see fixture designs. Make the designs so the trouble can easily be seen.
• Locate the datum features high above the fixture top surface so the chips can would drop below for easy removal.