Pulling weeds by hand eats up whole evenings, and chemical sprays are something many gardeners would rather skip. That frustration is what started this project: Hello World HD designed and printed an attachment that turns a string trimmer into a chemical-free weed destroyer, and gave it the very fitting name obliterator.
The part swaps in place of a standard spool cap and sits on the trimmer head as a bright orange disc ringed with angled teeth. It was modeled in Blender, printed in PLA on an Ender 3, and joined with super glue. The build consists of a body, two locking tabs, and an underside carrying large teeth plus a central stability spike. Materials came to roughly $1.10 of filament and $0.22 of glue.
Several choices stand out. The body is split into two halves to eliminate the need for large supports, and the locking tabs are printed horizontally to prevent them snapping between layers. The design also evolved from a surface covered in small spikes to fewer, well supported teeth, which reads as a genuinely iterative process. Files are available on Thingiverse, and the attachment fits Black & Decker trimmers in wired and cordless form, with listed models including BESTA510, CST2000 and GH600 on machines marked 13 in.
There is one clear trade off: the tool is aimed at smaller weeds, which the disc chews up entirely while displacing them, while large, thick weeds likely are not fully destroyed unless they are dug into the ground. The maker's detailed explanation closes with a demonstration of the attachment clearing weeds in a garden.
Project by Hello World HD. Watch it on their YouTube channel: