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Power Tools for
Comedian Tim Allen’s most
enduring character is Tim Taylor,
of the ‘90s television show Home
Improvement. Tim was the overzealous host of a how-to program on
using — and abusing! — tools and
hardware. In just about every eposide,
Tim attempted to “improve” some
tool by adding extra horsepower. And,
of course, it always backfired.
Tim was a man who obviously
loved tools and what they could do.
For many, part of the fun of building
robots is playing with the tools used to
construct them in the first place! The
right tool makes robot building easier,
faster, and safer. For larger projects —
or those that require you work with
denser materials such as metal —
power tools cut the job down to size.
You use the power of the tool to
enhance your construction capabilities.
In this column, we will review
some major makers and sellers of
power tools useful in building robots.
Of course, there are many kinds of
power tools and none are specifically
engineered for “robot construction,”
but what follows are the most
common and most useful.
The Power Behind
Your Power Tools
Power tools are equipped with a
motor — usually electric or air — to
make them work. They get the job
done faster and are best suited for
working with harder materials like
polycarbonate plastic or aluminum
metal. Electric tools are further divided
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into two general forms: AC or battery.
AC powered tools plug into a wall
outlet. That means you have to work
where an electrical socket is nearby.
You can extend the range of the tool
somewhat by using an extension cord.
Battery operated tools use
rechargeable batteries, so you don’t
need a wall outlet or extension cord.
You plug the tool (or the battery)
into a recharger, and once recharged,
you can use the tool until the
battery wears down. The obvious
disadvantage to battery operated
power tools is battery life. If you use
the tool for extended periods, you’ll
need extra batteries so you can switch
them out. You can use one set of
batteries while the other set is on the
recharger. Air tools require a tether to
a compressor or air tank. Most air
tools require a compressor (or air
source) that can deliver about 80-100
pounds per square inch (PSI) of
pressure. This means you probably
won’t be able to use the small 12
volt mini-compressors used for filling
automobile tires while stuck out on
the road. And, depending on the
needs of the tool, the compressor will
have to deliver a certain volume of air
— a rating known as SCFM or CFM —
for standard cubic feet per minute.
Tools like the drill or impact wrench
consume between 3-5 SCFM.
Which is better — electric (AC or
battery) or air? They both have their
pros and cons. Electric tools are more
mobile because you only need an
electrical outlet and possibly an
extension cord. If the tool is battery
powered, you can use it — up to the
capacity of the battery — anywhere,
even out in the field. Conversely, air
tools often have more torque for
their size, and if maintained properly,
last longer than the average electric
power tool. However, air tools need
a constant source of compressed air,
which means a bulky compressor or
large air tank.
The absolute most common
power tool is the electric drill.
They are also the most familiar to
everyone, regardless of previous
robot construction experience. The
drill uses a drill bit to make holes in
something. They’re also useful — at a
slower speed — as power screwdrivers.
Take the drill bit out and replace it
with a screwdriver bit. Set the drill
motor to a slower speed (or just apply
a little bit of pressure on the trigger)
and you can install or remove screws
in record time. You’ll need a reversible
drill for this; most already are these
days, but check before you buy. A
model that is reversible and lets you
adjust the speed is ideal. For more
robust constructions is the drill press.
It’s a drill motor mounted on a sturdy
column. These are used when you
need more control and precision over
the holes you bore into the material.
On the low end of the scale is the
portable drill conversion kit, which lets
you mount your handheld drill motor
to a stand. If you have the space and
budget, I highly recommend a bench
drill press. These plug into the wall
socket and their speed is adjustable
either electronically (turn a knob on