I got a 1/4inch and a 3/8inch collet with my Katsu.
I agree about 1/8inch collets; can’t find anyone offering one.
It would be good to get one to increase the range of cutters.
I do have a small pin vice which has a 1/4inch shaft and a collet which can hold 1/16inch diam drills.
That might work, although it would stick out a bit too far (3 inches)
No, I haven’t yet used the Katsu. Although am getting closer, but I need to finish off the final bolt-holes in my universal spindle holder to stop it from sliding up and down.
I will report back when I have some experience of the Katsu.
I have been trying out EstlCAM and can now get it to output a gcode file which I put on the SD card and feed it to the RAMPS 1.4/Arduino boards through the full-graphic LCD screen add-on.
I stuck a sharp pencil stub in the collet of the Katsu and watched as it traced (safely in the air) the vector drawing of an instrument panel for my LCD screen above the actual (laser-cut) panel (see photo attached).
I have been experimenting with manually editing the gcode file to get a better understanding of how it all works.