This mechanical/electronical additional unit "scans" the surface of the workpieces. Together with special software functions from nccad4 onward you can use it for 3 different applications:
To keep the depth when engraving and cutting (depth control)
To scan a three-dimensional surface (digitalizing)
To measure thickness (automatic measuring)
The entire additional unit is fixed to the y-table of the CNC-machine. At the side, an adjustable sensor arm goes to the place of work. Fixed to it is a movable sensor lever with a sensor. It "scans" the surface of the workpiece, moving the sensor lever up (Z-position too deep) or down (Z-position too high) according to Z-position, and releasing via light barrier an impulse and switching on a display lamp.Together with a software function this message can be read in three different ways:
Depth-control: The position of the sensor lever- and with it the depth of the tool (f.e. engraving router) is kept constant, the software regulating directly the Z-position and correcting the positions "too high" or "too deep". The sensor lever is basically kept in the same position, none of the display lamps may be on for long. At the same time a thin workpiece can be pressed down by the lever construction and the sensitivity is increased.
Scanning (digitalizing): A three-dimensional body is approached line per line from above until the sensor lever sends the message "too deep". The actual X-,Y-,Z-position is stored in a "surface file", which can be utilized for milling a copy of the workpiece. For this application you have to instal a special sensor that can be moved in all directions.
Measuring thickness:The Z-table goes down until the surface of the object is touched and the message "too deep" is given. The actual Z-position tells the thickness (height) of the object. If you arrange several objects on the Y-table in lines and columns you can do serial measuring with a test program. The measuring data are written automatically in a file and can be evaluated in a spread sheet program.
Engraving with the depth controller:
The conical engraving router is guided by the sensor, a change of the depth makes the Z-table move into the opposite direction, so that the thickness of the engraving is kept constant.
Scanning with the depth controller:
The three-dimensional body is approached point by point from above until the message "too deep" is given. This operation is repeated line by line and the scanned positions are written into a surface file to be used for working and milling copies.
Measuring the thickness by the depth controller:
The objects to be measured are approached until they are touched, the corresponding Z-positions are saved. Editing the data afterwards can be made with with usual software, like spread sheet program.