Liyu style drag knife cap for the Mostly Printed CNC https://www.thingiverse.com/thing:724999 by Allted. Should fit snugly to protect blade from getting chipped or cutting something you don't intend to get cut. I had issues with what to do with the drag knife when it wasn't mounted on the machine, so I printed this cap it has a internal curve that matches the liyu style cutter sold here: https://vicious1-com.myshopify.com/products/drag-knife-vinyl-cutter It also has a 1mm gap designed in around where the blade should be to protect the blade from bumping anything. Should be a fast easy print. Print flat side down.