I grew up in the West, and there I learned early in life that
wormdrives were the superior circular saw. When I was a
teenager, those were the only saws I ever saw on framing sites
in Colorado and New Mexico. Carpenters in that part of the
country talked about sidewinders in a deriding tone and called
them bowling balls, owing to their purported tendency to roll
off roofs.
Things seem to be different today. In the last few years, on
every job I've worked -- in Maryland, New York, and Vermont --
at least one other carpenter has had an inline saw. Many of
them have been DeWalt 378s (see Figure 1), and recently I ran
into the Bosch 1677 (Figure 2), the latest contender. I've
grown hopeful that a revolution is in the air.
Figure 1.DeWalt's inline offering, model 378, uses
hypoid gearing instead of a traditional worm gear. Detractors
claim that hypoid gears aren't as durable, but advocates point
out that they run quieter and the sealed gearbox means less
maintenance.
Figure 2.Bosch has the industry's newest inline
offerings and is attempting to convert sidewinder users with
its top-handle model 1678 (above left). Bosch claims that the
design gives users the benefits of a wormdrive in a platform
closer to what they're accustomed to. Model 1677M (above right)
has a more traditional setup and shares a housing and rear
handle with the West Coast favorite, Skil's model
77.
But my inline-centric viewpoint changed in 1980, when I moved
to the East Coast and began working mostly for remodelers and
as a finish carpenter. Whenever I unpacked my saw, the other
carpenters raised their eyebrows, or laughed out loud, making
remarks like, "Why don't you just grab a chainsaw while you're
at it?" Rarely did I see another wormdrive on site; when I did,
it was on a timber-frame or commercial site.
History 77
The division between East and West is a classic tale. You may
have heard it before, but here's a recap: The Skil 77 -- the
same model wormdrive that today captures nearly 90% of the
wormdrive market -- was invented in 1937 by Edward Sterba of
the Skilsaw Company. It evolved from a sugar-cane saw that
Edmund Michel invented in Louisiana in 1921. That tool used a
motor from a malted-milk mixer mounted on a machete handle and
a wormdrive gearbox to spin a tiny 2-inch blade. Although the
tool wasn't much good for harvesting sugar cane, it captured
the attention of Joseph Sullivan, a Chicago businessman who
happened to be traveling through New Orleans. Sullivan tracked
down Michel and proposed a partnership to develop the saw for
the construction market.
Sullivan and Michel set up shop in Chicago under the name
Michel Electric Hand Saw Company (later dubbed the Skilsaw
Company) and received a patent for the first wormdrive circular
saw in 1924 (Figure 3). They built six, at a cost of about
$1,000 total. They took three to Atlantic City, N.J., where the
boardwalk was under construction, and three to Los Angeles,
where a housing boom was beginning to take off. Despite myriad
problems with these primitive tools, carpenters in both regions
expressed enthusiasm for the wormdrives, setting the stage for
distribution on both coasts. But several events led to a far
greater distribution in the West. For starters, home building
along the Pacific Coast spread the saw over a large area, while
construction on the East Coast was mostly concentrated on
commercial sites in big cities. During the depression,
construction crawled, but the Army Corps of Engineers adopted
the saw, taking it to Work Project Administration (WPA) sites
throughout the western states, and later to hydroelectric and
irrigation projects, from which the Skilsaw eventually spilled
over onto construction sites. But perhaps the biggest reason
the Skilsaw didn't take off in the East was the competition
from Porter-Cable.

Figure 3.The original wormdrive made by Skil
evolved from a malted-milk mixer with a 2-inch blade and a
machete handle. It helped build Atlantic City's boardwalk but
never caught on in the East. A housing boom and depression-era
WPA projects out west led to greater acceptance there. The saw
still captures almost 90% of the wormdrive market.
The Porter-Cable Machine Company was a well-established
toolmaker by the time it entered the circular saw market in
1929. World War I had given the firm a boost when the demand
for short-bed machine lathes and milling cutters soared. After
the war Porter-Cable acquired the Syracuse Sander Company and
began making floor, belt, and spindle sanders, as well as other
woodworking equipment. The first Porter-Cable circular saw
(Figure 4) was invented by Arthur Emmons. Since Skilsaw owned
the patent on the wormdrive, Emmons developed a model dubbed
the Kwiksaw, with the blade on the right and the motor sitting
"sideways" -- perpendicular to the blade. The saw was indeed
quick. It ran full bore straight off the armature -- no gears,
just one hell of a big winding. Thus the "direct-drive"
circular saw was born, and thereafter was marketed heavily in
the well-entrenched Porter-Cable markets in the East.

Figure 4.The original sidewinder, made by
Porter-Cable, spun right off the motor without a transmission
because Skil already had a patent on a geared design. The saw
was accepted because of PC's established eastern market and
reputation for building quality woodworking
equipment.
Hypoid vs. Wormdrive
In the 1970s Makita pioneered the use of the hypoid gear train
in an inline saw, and it has since been adopted in DeWalt's
inline saws. A hypoid gear is a finer-toothed gear system
enclosed in a sealed case. By contrast, a wormdrive gear is a
meatier, spiral gear bathed in oil that must be replenished
periodically. Hypoid advocates claim that their beveled spiral
gears mesh more closely than the gross coils on a worm gear,
resulting in smoother power transmission and cooler, quieter
operation. Critics argue that the hypoid has less shock
resistance (a common example of shock is the force a saw takes
when it runs into a knot at full speed) and will wear out more
quickly than a worm gear.
While hypoid-drive saws run noticeably quieter than
wormdrives, none of the other differences is worth getting too
excited about. For starters, both designs run three to four
times longer than most sidewinder saws, according to
manufacturer reports. That might sway a few sidewinder users,
but it's features like weight and balance that have the most
discernible influence.
What You're Used To
"It's all in what you're used to," explains Randall Coe of the
SB Power Tool Company. "If you started out with a 9- or
10-pound saw, you're never going to be comfortable with one
that weighs 15 pounds." Inline saws weigh from 13 pounds
(DeWalt) to almost 17 pounds (Milwaukee). Wormdrive users love
the weight, arguing that a heavier saw is easier to control
("It doesn't bounce around"), almost exactly the same argument
sidewinders use to tout their saw ("It's easier to
maneuver").
In an effort to corral some of the sidewinder market, Skil
explored the use of magnesium housings to shave weight off the
77, and the same housing has been adopted for the newest inline
saws, Bosch's 1677M and 1678. Bosch wants to take the weight
reduction program even further and is exploring a new line of
heavy-duty, lightweight tools to be introduced in the near
future. But Randall Coe argues that the weight is in the motor
and the gear train, and there's no real-world way to lighten
those without sacrificing longevity. "If you want the
durability of a wormdrive, you have to contend with the
weight," he says.
Chances are good that if a wormdrive saw could be made as
light as a sidewinder, it still wouldn't win over the pack. The
balance, the hand positions, the whole dynamic of using an
inline saw is different. This translates into work methods.
Most sidewinder users are horrified by the way I cut framing
lumber by propping the boards on my ankle. They prefer to hoist
the lumber onto horses at waist level -- an unnecessary waste
of energy, I think. But there you have it. Coe's right. It's
all in what you're used to.
Despite my desire for a revolution, the classic division
between East and West still holds. Those inline sightings I've
had on East Coast job sites may be an anomaly, according to
market distribution reports. The majority of inline saws are
still sold out west, except in the commercial trades, which
don't seem to have tool-specific boundaries. Or when I spotted
those carpenters with their inline saws, I might just have been
working in the company of superior beings.
was a longtime senior editor at
The Journal of Light Construction
and a
founding editor of Tools of the
Trade