Geoff’s Musings
Cutting Heads for Brushcutters
Most straight shaft machines can handle a steel cutting blade if needed but beware steel blades are totally unforgiving. Whatever they hit, they cut or smash – or even worse smash the gearbox and drive shaft in your machine.
An alternative available for most machines is the swinging plastic blades. These cut faster than nylon line but still bend back if they hit a rock or similar. A big advantage is that they do not tangle in wire fences like nylon line, or cut the wire as steel blades would.
Generally, curved shaft machines are suitable only with nylon line heads.
A common mistake we see is the nylon line far too long. Remember, nylon line only cuts because of its speed (i.e. revs). A line too long causes significant load on your machine dragging the revs down where it becomes ineffective.
The trick is to keep the revs high enabling the line to be an effective cutter.
I’ve heard of people using wire instead of nylon – this is extremely dangerous as the wire will snap and becomes a missile travelling much further than a piece of nylon line.
Another tip is to ensure you have the correct thickness of line for your machine. As mentioned, the nylon line only cuts because of its speed. Hence a line too thick will overload the engine, just like a line too long and cause a significant drop in revs. Hence less cutting power. Most machines have a cut off blade on the guard to ensure the cutting line is of the correct length.
STAR or SQUARE LINE
These lines have an advantage in “hard to trim” type grasses. They do cut faster but as with most things, there is a negative – they wear out faster!