This model is inspired by Woodpeckers Mighty Mini Carbide Insert Glue Scraper ($31). You can purchase the insert on AliExpress.com - just search for "Wood Carbide Insert Milling Cutter". This will cost you about $2 (free shiping to some countries).

The handle is designed for 14-15 mm (9/16 - 19/32 inch) inserts. 16 mm (5/8 inch) would fit too.

You will also need a holding screw. I recommend using undersize screw, so different size inserts can be moved up to lean against the upper ledge.

You may need to modify the model depending on what screw size you are going to use, and if you are going to use threaded insert. You can also use drill to enlarge hole post-printing. The hole in the model is 5mm (diameter) x 9.5mm (length), then 4.5mm (diameter) x 16mm (length).

Print Settings

Printer Brand: MK3

Printer: Prusa i3

Rafts: No

Supports:  Yes

Resolution: 0.3

Infill: 20

Filament: Filamentarno ABS Black 
 

Notes: 

0.5x0.3 layer, 6 tops, 6 bottoms, 6 shells. Support is required for cavity on the side. Consider using brim.