Weed Whacker/Trimmer Bump Knob

The bump knobs on string trimmers are considered a wearable part and the design is pretty much standardized. Hardware stores usually sell them in two packs. But why spend the time driving to get one or waiting days for it to show up at your mailbox when you can print one in about an hour or less? Also, you can print a dozen of them in whatever material you want for the same price as a new one!

The picture is of my Ryobi trimmer, but the knobs are almost always the same no matter what string trimmer you have.