Lightweight Surface Plate Cover

[Paul Jones]

Marv,

Thanks for pointing out the tipping issues. There are exact ways to calculate the ideal position of the three support locations on the bottom of the surface plate. Most surface plate manufactures use a Fed spec to locate the support positions or companies such as Starrett recommend using the rule of thumb: "A surface plate should be supported at 3 points, ideally located 20% of the length in from the ends of the plate. Two supports should be located 20% of the width in from the long sides, and the remaining support should be centered".

Other surface plate manufactures such as Standridge Granite mark the bottom of their surface plates to shown where it was supported during the surface lapping and inspection process and expect the owners to support the plate in the same locations.

Paul