Re: [CAD_CAM_EDM_DRO] Re: Make your own linear scales

Art Fenerty wrote:

> How about the scales which are a tube filled with precision ball bearings.
> You then use a few coils on the sensor and have the sensor slide along the
> stainless tube. As the coils get closer to each ball bearing they create the
> phasing signals. Sounds like a beast to calibrate, but sounds easy enough to
> make and is impervious to contamination.

The problem is the high degree of interpolation required. They multiply the
ball
pitch by at least a thousand, so there is lots of high-precision analog signal
processing involved.

Jon