Grizzly G0860 Owner's Manual page 32

Determining Main Line Duct Size
The general rule of thumb for a main line duct is
that the velocity of the airflow must not fall below
3500 FPM.
For small/medium sized shops, using the inlet size
of the dust collector as the main line duct size
will usually keep the air velocity above 3500 FPM
and, depending on your system, will allow you to
keep multiple branches open at one time.
Mark your drawing, as shown in the figure below,
but using the inlet size for your dust collector as
the main line.
Jointer
Planer/
Moulder
400
Miter
5"
Saw
100
Shaper Table Saw
Figure 42. Main line size labeled on sketch.
Determining Branch Line Duct Size
The general rule of thumb for a branch line duct is
that the velocity of the airflow must not fall below
4000 FPM.
For small/medium sized shops, using the dust
port size from the machine as the branch line duct
size will achieve the correct velocity in most appli-
cations. However, if the dust port on the machine
is smaller than 4", make the branch line 4" and
neck the line down right before the dust port.
Note: Systems with powerful dust collectors work
better if multiple blast gates are left open. This
also allows you to run two machines at once.
Experiment with different combinations of blast
gates open/closed to find the best results for your
system.
Write your determined branch line sizes on your
drawing, as shown in the following figure.
-32-
Sander
400 850
6" 7"
Dust
Collector
Planer
Planer/
400
Moulder
4"
5"
Miter 4"
Saw
100
4"
250
Shaper Table Saw
Figure 43. Branch line duct sizes labeled.
If two machines will connect to the same branch
line and both will operate at the same time, then
add the required CFM for each machine together
and find the closest total CFM in the table below
to determine the correct branch size.
If both machines will never run at the same time,
reference the machine with the biggest dust port
in the table below and add blast gates after the
Y-branch to open/close the line to each machine.
Total CFM
400
500
600
700
800
900
1000
Figure 44. Sizing chart for multiple machines on
the same branch line.
Model G0860/G0861/G0862 (Mfd. Since 10/18)
Jointer Sander
850
400
4" 6"
6" 7"
Dust
Collector
4" 5"
400
600
Planer
Branch Line Size
4"
4"
5"
5"
6"
6"
6"