It is difficult to get a perfect smooth surface through machining process.
What scraping process does is scraping the surface with a blunt tool by hand, making it a little kind of bumpy, so to reduce friction resistance between sliding surfaces.
This requires long experiences and the number of skilled experts is declining.
we apply the technique to optical machine, in order to make it more precise while preventing degradation over time.
The purpose of scraping
To get a surface with highly precise flatness, squarerness, straightness.
it also creates oil pockets allowing the sliding motion more smooth.
- Grinding: bed, wheel head, circular base
- Presetter: spindle installation area, column
'Scraping skill' is a technique that scrapes metal surface with a blunt tool to improve the flatness and create oil pockets.
For highly precise machines that are critical to manufacturing ultraprecision products, It's most important component-sliding surface must be processed with this technique in order to get flatness of 1/1000mm.
Even with today's up-to-date technology, it is difficult to be done by machining but with human hand.