Thin knob for M3 nut

My Discoeasy has a bed level defect... but the bed is not adjustable in standard.
At the beginning, I could only print small parts... so I designed a small part !

This knob has been designed to be used with the self-locking
nut provided with the Dagoma Discoeasy 200 to fix the bed.
For each bed's support, you must use :
- a 25 mm countersunk head screw,
- a small spring (I don't know the reference because I re-used old springs but something like 5mm x 10mm)
- 2 standards M3 nuts

Put