Types of string trimmers
A string trimmer cuts through grass and weeds with a thin nylon line, which
is rotated at high speed by either an electric motor or a gasoline or propane
engine. Also called grass trimmers, line trimmers or weed whackers, these
tools make trimming and edging a lawn much faster and easier than using hand
tools like grass shears. The best string trimmers can handle tough weeds
and tall grass along fences and keep a long driveway trimmed. String trimmers
can also reach under shrubbery and cut grass in hard-to-reach places.
There are three main types of string trimmers, each with advantages and
- Electric string trimmers: Corded trimmers are lightweight, and
the best models can power through tough weeds as effectively as gas-powered
trimmers. However, their range is limited to the length of an extension
cord (usually 100 feet, with a few exceptions). If your trimming work
is light and can be completed within half an hour, a cordless electric
trimmer is an option. Both types are quiet and produce no fumes.
- Gas trimmers: For
big lawns or for cutting tough weeds and tall grass, gas-powered string
trimmers are a more powerful option. You aren't limited by a cord, but
you do need to buy and store gasoline. Two-stroke models, the most popular
kind, run on a mixture of gas and oil. Four-stroke models, which run on
gas only, are more powerful, more efficient and produce lower emissions.
However, they also tend to weigh more, are harder to start and vibrate
more than two-stroke models. Four-stroke models also have more moving parts,
which means they require additional maintenance. Both types of gas trimmers
are loud enough that you will need some kind of hearing protection while
string trimmers: Propane trimmers can be as powerful as gas trimmers,
but they use 16.4-ounce propane canisters for fuel. The upside is that
propane is far less polluting than gas, and twisting the canister into
place is much simpler than mixing oil and gas. The downside is that the
canisters, which cost between $3 and $5 each, only give you about two hours
of run time and can't be refilled.
Differences in shaft types
String trimmers come in three basic designs: straight-, curved- and split-shaft
models. A straight shaft gives you a longer reach and may be better for taller
users. It's also better at reaching under shrubbery. Trimmers with a curved
shaft, however, tend to be lighter and easier to handle. Split-shaft trimmers
are the most versatile, since you can remove the string-trimmer head and
attach a variety of other accessory tools, such as a leaf blower or edger.
However, the editors of ConsumerReports.org say that these add-on
tools often don't work very well.
Experts offer the following advice for buying a string trimmer:
- Choose the
right power type for your needs. Reviewers generally say that cordless
trimmers (and some electric models) are less powerful than gas or propane
trimmers. However, they're quite adequate for light-duty trimming. Many
cordless models will only run about 20 minutes on a fully charged battery,
but extra batteries can extend their run time. If you need to whack tall
grass or weeds, you're probably better off choosing a gas or propane model.
- Good balance
is just as important as weight. The string trimmer's weight should
be evenly distributed or slightly heavier toward the top. A bottom-heavy
trimmer will be harder to handle.
- Some trimmers can take attachments. Many string
trimmers can double as edgers or accept attachments such as metal blades
for cutting heavy brush. Look for a rotating head that flips to a vertical
position if you want to edge your lawn.
- Check the feed mechanism. Most string
trimmers are loaded with a spool of line that unwinds automatically.
This is fine when it works, but jamming is a common problem. Bump-feed
systems advance the trimming line when you tap the trimmer's head on the
ground, but some users find this hard to use. Owners also say refilling
a string trimmer line can be tricky on some models. An alternative is a
fixed-head trimmer, which uses line in small precut lengths instead of
unwinding it gradually from a spool. Owners say this feature eliminates
jams and tangles, and it only takes seconds to insert a new piece.
- Extra features are useful
on gas trimmers. Spring-assisted ignitions make it easier start a gas-powered
trimmer. A translucent gas tank is also handy because it lets you know
when the machine needs refueling. Finally, consider buying a shoulder
strap or harness for comfort and back safety if your string trimmer doesn't
come with one.
- Left-handed users need rear exhaust. Look for a trimmer with a deflector
that can send the exhaust to the rear instead of to the side, where
it will hit left-handed users.