Shop fox W1867, Owner'S Manual

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Model W1867/W1868/W1869 (For Machines Mfd. Since 11/18)
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Figure 36 . Example of flexible metal duct.
Flexible.Duct Metal.Duct
Figure 35 . Examples of smooth metal duct and
components.
Advantages of smooth metal duct is its
conductivity, efficiency, and that it does not
contribute to static electrical charge build-up.
However, static charges are still produced when
dust particles strike other dust particles as they
move through the duct. Since metal duct is a
conductor, it can be grounded quite easily to
dissipate any static electrical charges.
There are a number of options when it comes
to metal duct, but metal duct that is specially
manufactured for dust collection is the best
choice. When selecting your metal duct, choose
high quality metal duct with smooth welded
internal seams that will minimize airflow
resistance. This type of duct usually connects to
other ducts or elbows with a simple, self-sealing
clamp, is very quick and easy to assemble,
and can be readily dismantled and re-installed
in a different configuration. This is especially
important if you ever need to change things
around in your shop or add more tools.
Avoid inferior metal duct that requires you to
cut it to length and snap it together. This type
of duct is time consuming to install because it
requires you to seal all the seams with silicone
and screw the components on the ends with
sheet metal screws. Another disadvantage is
the rough internal seams and crimped ends that
unavoidably increase static pressure loss.
Flexible hose is generally used for short runs,
small shops and at rigid duct-to-tool connections.
There are many different types of flex hose on
the market today. These are manufactured from
materials such as polyethylene, PVC, cloth hose
dipped in rubber and even metal, including steel
and aluminum.
The superior choice here is metal flex hose that
is designed to be flexible, yet be as smooth as
possible inside to reduce static pressure loss.
There are also many kinds of pure plastic
flexible hose, such as non-perforated drainage
type hose and dryer vent hose. Drainage type
hose, while being economical, does not quite
have the flexibility required for dust collection.
The inside of the duct is also deeply corrugated
and can increase the static pressure loss by
as much as 50% over smooth wall duct. Dryer
vent hose, while being completely flexible, is
non-resistant to abrasion and has a tendency to
collapse in a negative pressure system. We DO
NOT recommend using dryer vent hose in your
dust collection system.
If using flex-hose, you should choose one of
the many types that are designed specifically
for the movement of solid particles, i.e. dust,
grains, and plastics. However, the cost of
specifically designed flexible duct can vary
greatly. Polyethylene hose is well suited for
the removal of particulate matter, especially
sawdust, since it is durable and completely
flexible. Polyethylene is also very economical
and available in a wide variety of diameters and
lengths for most applications.