Spindle Pen Holder
I use a series of horizontal lines on my CNC spoil board to aid in placement of parts before clamping. In the past, I drew these lines by hand by connecting dots on the spoil board that were lightly dimpled by the machine. It took a long time and sometime the pen got stuck in a groove which resulted in wayward lines. The pen holders commercially available all had some drawbacks like special holders or pens. By making a pen holder that used a Sharpie marker that was easy to adjust and insert into the machine’s spindle collet, I simply programmed the machine to draw the lines. It’s accurate, fast and easy to do each time the spoil board is re-surfaced. The pen is adjusted so the point is coaxial with the bolt that is inserted into the collet. Z zero is set to the top of the spoil board and the lines are drawn with a “cut” depth of 0.002″ or so. Obviously, the router or spindle is not rotating. The fact that the block slides on the bolt lets the pen tip move a bit when the pen encounters a bump. This thing works like a charm!
Lines drawn on a freshly surfaced spoil board make short work of lining up objects parallel with the gantry.