Summary When you write or cut on uneven surface, you need pressure and some few millimeter backlash For a 8mm pen diameter You'll need 3 springs for the 8 mm floating distance. It was designed to be CNC 3 axis -able and 3D Printable ;) All the sliding parts are 0.50mm away from each others. I didn't make it yet but I'm pretty confident all is OK ! 99% sure ;) If you want any other file format, feel free to let me know ;) I'm planning to make thé design accessible through FUSION 360 sharing function. You can support me : https://www.patreon.com/myke974 ;) How I Designed This I designed a CNC from scratch and I want it to be multitool able ! This is for holding a Pen or scalpel.