This is an attachment i came up to in order to press drill pcb in a very small package. you press the dremel and it makes the hole in the pcb. once you let it go, it will automatically rise up and prevent the drillbit to break. plus, the hole is perfectly straight
the object is fully 3d printable without support. the only thing it needs are 6 springs ( 5.5mm diameter x 15mm length).
I tested it in dremel 3000. i suppose it will work iin dremel 4000.
for pcb drilling, i suggest using the lowest rpm rating the dremel has, otherwise you can take the chance of breaking the drill bit.