... at home i checked the tecspecs of my old 'Summasketch III Professional'-tablet:
- active area = 12 x 18" or 305 x 457 mm
- resolution = 2540 lines per inch or 100 lines per millimeter (=10 micron)
- accuracy = 0,010 In or 0,254 mm ???
The tablet has a stylus and a 4-button-mouse, which would do better.
(I found an Aiptec-HyperPen-tablet too, but the active area is only 10 x 12,5 mm and the stylus is battery-driven, so the Summasketch is much better adapteble and for larger scales)
The resolution is good enough for servo-driving, so i hope to adapt the mouse to the toolhead and use the tablet as absolute reading.
The main problem would be the software to read the tablet-output in the reprap-software ...
If the overall accuracy should be a problem, there could be a mechanical upscaling of XY-movement to the digitizer-mouse 2- or 4-fold, so that the measured area for the reprap-toolhead would be smaller, but with a higher accuracy ...
Viktor