Hyd-Mech DM8, Use And Maintenance Manual

Page: 149 / 156

MEP S.p.A.
10--4 Use and maintenance manual DM 8
PROBLEM PROBABLE CAUSE SOLUTION
Teeth broken (continued)
' Material defective . The material may display altered
areas on the surface, such as oxides
or sand, and in the section, such as
subcooled inclusions. These areas
are much harder than the blade and
will cause tooth breakage: scrap or
clean these materials
'
Workpiece not clamped
.
If the piece moves during cutting
teeth can be broken: check the vice,
the jaws and the clamping pressure.
' The blade stops in the cut . Cutting pressure too high: check
pressure and set to rated pressure
.
Head downstroke too fast: reduce
speed
.
Cutting speed too slow: increase
.
The blade slips on the flywheels: ei-
ther the flywheels are worn and
therefore need to be replaced, or the
blade tension is incorrect (too low)
and should be set back to the cor-
rect tension
' New blade inserted in a partially ma-
de cut . The surface of the cut may have
been subject to a localised heat--in-
duced alteration, making it harder:
when restarting work, set a slower
cutting and head downstroke speed
. A tooth from the old blade may be
left in the cut: check and remove be-
fore restarting work
'
blade guides positioned incorrectly
.
Adjust the position of the inserts, es-
pecially the width, since blade thick-
nesses can exceed the manufactur-
er’s declared tolerance ratings
'
Widia blade steady buttons
.
Two widia blade steady buttons are
located in the top part of the blade
guide heads and press on the back
of the blade to transmit cutting pres-
sure. If these buttons are too far from
the blade, the blade itself may suffer
from an up and down undulating
movement or abnormal vibration, li-
able to lead to breakage of teeth: ad-
just the heads position, rotating them
downwards so as to bring the blade
steady buttons up against the back
of the blade
'
Sections with large thickness varia-
tions
.
Cutting and head downstroke
speeds must be chosen in relation to
the most demanding part of the cut.
' Teeth pointing in wrong direction . Fit blade so that teeth point in the
right direction