206 Agricultural Mechanics and Technology Systems
Copyright Goodheart-Willcox Co., Inc.
For a stationary power tool, scroll saws are not very powerful and are fairly
safe to operate. The blade’s stroke length is usually less than 1” and the teeth,
although sharp, are small. They can still cut fi ngers, but the potential damage
is far less than with other, more powerful saws.
Scroll saws, unlike band saws, are capable of center cuts that do not open
to the edge of the work. By piercing a hole with a drill bit fi rst, then threading
the blade through the workpiece before mounting the blade to the saw, the
user can make a cut from the center of an object.
Scroll Saw Blades
Although a few light-duty saws use shorter ones, most scroll saws use a
5″ blade. Blade widths vary from almost 1/4″ to less than 1/16″. Blades have
either plain ends that are clamped into the blade holders or pin ends with
tiny round cross pins that fi t into slots on the blade holders. The plain-ended
type of blade is the most common.
Tooth arrangements vary greatly to accommodate use in many
applications. The general rules for selecting saw blades also apply to scroll
saws. More teeth per inch create a smoother cut and cut through denser
materials than coarse blades. Coarse blades remove waste material better as
the saw cuts. Small, fi ne blades remove less material, leave a narrower kerf,
and are better for tight turns and intricate curves. Twisted, or spiral blades,
are designed with cutting edges on all sides to enable easy, sharp turns with
the blade.
Oscillating Multi-Tools
Oscillating multi-tools are portable power tools
designed with a mechanism that rapidly vibrates a
blade or other attachment back and forth in a narrow
arc. The entire motion is only a shift of 3° to 4°, but it
vibrates at up to 21,000 strokes per minute.
Attachments are mounted to the front of the tool
with the cutting edge or working surface extended out
to the front. The result is a tool with the ability to reach
into tight places or make cuts fl ush with an existing fl at
surface. Attachments are available to cut wood, steel,
tile, and other materials. Additional attachments allow
completion of other jobs, such as scraping or smoothing
surfaces. The tool and some of its various accessories
are displayed in Figure 8-38. It can be powered through
a traditional electric cord or it may be cordless. When
used in the proper situations, oscillating multi-tools are
both versatile and effi cient.
Routers
The basic router is a portable woodworking
tool consisting of a powerful electric motor, a rotary
cutting tool, and an adjustable base plate to control
Oleksandr Chub/Shutterstock.com
Figure 8-38. The unique configuration of oscillating
multi-tools allows them to reach into places where
other power tools cannot. Attachments for the tool
provide flexibility to cut, scrape, dig, and sand.