CNC Sharpie Holder (spring loaded)

Soooo I need to change the wasteboard bed on my CNC and changing the layout to something a bit better for me so I need to plot the work area. There are lots of options but I wanted to use a sharpie and wanted to be straight up and down for where the spingle would do it's thing.

While I could have made something simple and rigid I had extra time so of course I made it more complicated. I made a 2 piece body that goes into the spindle so you can have a direct line. The body also helps lock in a 12mm spring to give the pen 10mm of play so its not entirely rigid. You may or may not want to use a half sized sharpie instead of a full length one (read the note at the end)

So to assemble you need a M6 x 30mm screw, a M5 x 15mm screw (this could actually be shorter) and a spring that fits over the M6, the one I had was 9mm diameter and roughly 12mm of compression. One of the pictures shows how to assemble but:

1. tap the holder hole with the M5 screw and the bottom of the body with the