You will need -
-Empty 1KG filament spool (spool holder section has a 1.7" diameter so the hole must be larger than that.) I used a Prusa 1kg roll, the one that comes with the printer as I figured a lot of people will have one.
- (2) Washers .75"OD .25"ID .08 thickness
-(2) Washers .55-.6"OD .25"ID thickness is not as important here, not too thick though.
-(1) 1/4-20 bolt between 1" and 1.3" long
-(2) M3 screws(bolts) with corresponding nuts
.28-.3" drill bit
.150" drill bit
The larger washers get sunk into the "interior" and "exterior" pieces that go into the side of the spool. This makes sure its metal on metal, rather than plastic on plastic. the two smaller washers go against the 1/4-20 bolt cap and the handle end. See photos for clarification. Everything else goes together exactly how it looks, nice and easy.
I don't recommend using this if you hook something large. I printed it in PETG and seems very sturdy, I have a 500lb magnet on the end, it will not handle something anywhere near that heavy.
(Edit: Added non-catch version of the interior handle piece. file is "magnet fishing spool interior"all lower case.)
3D Solutech PETG
Print with support angle at 50 and set to build plate only. I printed the large section with the handle angled up flat on the top surface.