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Thermo Fisher Scientific
Operation Manual HM550
e motorized cutting drive facilitates routine work and ensures an even
cutting speed also for harder specimens.
When using the motorized cutting drive a regulated D.C. motor works
on the hand wheel of the cryostat microtome by means of an electrome-
chanical clutch and a reduction gear.
e speed of the motorized drive can be pre-selected continuously on
the operating controls from 0 to 250 mm/s. e selected speed will be
carried out in the cutting window.
Outside the cutting window a higher return speed is determined by the
electronic control unit. Use either the operating controls or the foot
pedal to turn on/off the drive.
e limits of the cutting window can be changed continuously and can
be adjusted to the specimen.
ree operating modes for the motorized cutting drive are available.
When in operating mode “interval stroke”, the cutting drive only moves
as long as the button START/STOP or the foot pedal is pressed. e
movement can be stopped in any position.
When in operating mode “single stroke” the cutting drive moves from
the starting position to the next lower reversal point.
When in operating mode “continuous stroke”, an unlimited number of
sections is carried out. To stop the continuous stroke, press the button
START/STOP or the foot pedal. e cutting drive will stop after reach-
ing the next lower reversal point.
In case of danger, the motor drive can be stopped in every operating
mode by pressing the emergency stop button or the emergency stop in
the foot pedal. Continue sectioning pull out the emergency stop button
or unlock the emergency stop in the foot pedal.
e compression of sections when gliding onto the blade is a well
known phenomena during sectioning in general and especially during
cryo-sectioning. However, this can be enormously reduced by using a
Vacutome with a special blade carrier.
For this, a vacuum can be set below the vacuum anti-roll hood via
an operating knob. is vacuum anti-roll hood acts as a traditional
anti-roll guide. By means of the suction vacuum prevailing in the slot
between vacuum anti-roll hood and blade edge, the cut is drawn on the
air cushion over the blade thus immensely reducing the compression.
e section remains on the blade in stretched form.
Option M –
Motorized cutting
drive
Option V –
Stretching sections
and disposing of
section waste
Theory of operation
Option M – motorized cutting drive
