ASTEC TF300B - Trencher Chain and Teeth

OPERATING INSTRUCTIONS
23 AU103168 C7B
Boom Position When Digging
For the best digging performance and smoothest machine
operation, the boom must be in the full down digging
position. In this position, the machine is pulled down for
better traction. The ground drive simply pulls the digging
teeth into the face of the trench.
When the boom is raised from the full down position, the
digging load pulls the machine more rearward. This
pulling reduces traction and may cause the machine to
bounce and pull when the chain contacts roots or rocks.
The rearward pull of the digging operation also works
against the ground drive causing the machine engine to
work harder.
B2228A88
TRENCHER CHAIN AND TEETH
Chain Types
The correct chain for the job is very important. Soil
conditions determine the type of chain needed. A chain
that is too light will wear fast or break. A chain that is too
heavy increases the load and slows the trencher speed.
Standard Digging Chain
The standard digging chain works fine in most digging
conditions. However, because of the design, the standard
chain teeth can rotate back (backflex) when digging in
heavy or rocky ground. When this backflexing action
starts, the teeth do not remain at the correct digging
angle and the trenching speed is reduced.
Anti-Backflex Digging Chain
This chain is designed for hard digging conditions. The
side plates of each link are close together. As the chain
leaves the sprocket, each link comes together with the
next and forms a solid digging channel. This action keeps
each digging tooth at the correct digging angle.
IMPORTANT:
Correct chain tension is very important for
this type of digging chain. See Digging Chain Tension for
Sprocket/Channel Boom in this manual.
Teeth
The most important parts of the trencher are the teeth.
The type of teeth that you select and the arrangement
you use makes a big difference in the digging efficiency
and tooth life.
RB97F067
NOTE: Additional digging teeth combinations may be available to meet particular soil conditions. See your Astec dealer
for additional information.
WARNING: Make sure all people are clear of the
machine and working area while the digging chain
is rotating. Serious injury or death can result from
contact with the digging chain or flying debris.
M
OS
T EFFI
C
IENT LEA
S
T EFFI
C
IENT
BOOM IN FULL
DOWN POSITION
BOOM NOT IN FULL
DOWN POSITION
DIGGING
LOAD
DIGGING
LOAD
SHORTER
LONGER