This is a remix of the CNC Pen by MrConcept. I liked the base design but wanted a version with a pencil. Since i'll be using it in the foldable CNC router i also increased the top radius of the base. It's now suitable for placement in the drill clamp for the pseudo dremel i'm using.

The measurements of the locking ring are:

Outside diameter: 14mm Inside diameter: 8mm (the diameter of the pencil i'm using is aprox. 7.5mm ) Height: 6mm

The Spring:

Diameter: 12mm Height: 22mm Thickness: 0.8mm