Addnorth HT-PLA Pro Matt
Works great, Prusament JetBlack PLA 0,3mm Draft
One suggestion: need to add a hole below the nut, so the screw has a place to go out of the nut...
Magnets 12x4 6pcs + 12x10 6pcs, or 12x4 12pcs.
Prrfect fit on an ER20 collet.
Printed it in eSun PLA-CF to make it as rigid as possible.