|Tool noise and vibration. Facts of
life in the world of power tools -- the annoying facts. But along with the
annoyance, I think there's also a safety factor. Loud noises and vibration lead
to operator fatigue, and fatigue to accidents.
So what can you do about it? I talked to the guys at ShopNotes to
get some ideas. First, you might be able to buy quieter tools. For example,
because it runs at a higher speed, a universal (brush-type) motor is louder
than an induction motor. Although most hand-held power tools use a universal
motor, you'll often have a choice when buying stationary tools.
Drive systems can make a difference, too. Generally, a gear driven tool runs
louder than one that's belt driven. The reason is simple. There's a certain
amount of "transmission" noise caused by gears meshing together. But
if you transfer power from the motor to the blade through a belt, it eliminates
Second, check out the tool stand. Sometimes, even the stand a tool is mounted
on can add to the noise level in your shop. Because a stand can loosen up with
use and start to rattle, it's a good idea to tighten down the bolts that hold
it together. (It's probably a good idea to check the bolts now and then whether
you're worried about noise or not.)
But noise can still be a problem if the stand flexes when the tool is running.
To keep metal parts from rubbing against each other, you need to insulate the
stand. One way to do this is to disassemble the stand and apply a bead of
construction adhesive between any parts that touch. Or just add weight or
ballast to the stand. (Concrete blocks or sand both work well.)
To insulate a stand from the floor use wood and rubber feet. Glue a piece of
rubber to the top and bottom of a small wood block. Then screw the blocks to
the feet of the stand.
But perhaps the best way to dampen noise is to replace open metal stands with
enclosed shop-built wood stands. To absorb as much noise and vibration as
possible, try to incorporate heavy, dense materials like particle board or
medium density fiberboard into the stand.
Drive belts and pulleys can also contribute to how much noise a tool makes.
With use, a "lump" can form on a belt where it's fused together. As
this lump passes across the pulleys, it can sound like a washing machine that's
out of balance. You can replace old belts with new V-belts, or try an
interlocking link belt that's designed to reduce noise and vibration.
No matter which kind of belt you use, a belt that's too tight runs louder. So
on tools with a fixed position motor (not hinged), back off on the tension just
enough so the belt doesn't slip.
Pulleys can be a source of excess noise, too. Many tools have pulleys that are
cast from a soft metal. Since these pulleys aren't always perfectly balanced,
they tend to wobble and make noise. You can replace those pulleys with ones
that are turned from solid pieces of steel.
And regardless of what kind of pulleys you're using they won't run quietly
unless they line up. To check this, use a straight edge. When held against the
pulleys, it should touch the outside edge of both pulleys.
Go to Tip #27