Sutter Instrument XenoWorks BRM Operation Manual page 36

24
Problem
One or more motors move
in the opposite direction to
that commanded by the
joystick.
The micropipette will not
move any lower.
The micropipette appears to
move in a direction opposite
to that commanded by the
joystick, but only in the Y-
axis.
The micropipette does not
return to the assigned
coordinates memorized by
the 'Work' setting.
XENOWORKS MICROMANIPULATOR SYSTEM (TOUCHDECLUTCH) OPERATION MANUAL – REV.
Cause
One or more of the axis
polarity DIP switches are in
the wrong position.
1. The end of motor travel
has been reached.
2. A 'Z-limit' has been set.
1. The Y-axis inversion DIP
switch is in the wrong
position.
2. A micropipette with an
angled tip has been
aligned such that the
bend or "heel" of the
micropipette is touching
the dish, but the tip is
not. This is usually only
noticeable at higher
magnifications.
1. No new 'Work' setting
was actually assigned,
and so the micropipette
moved to a different,
previously assigned
position.
2. Repeated rapid, violent
movements of the
joystick may cause the
instrument to miss
information coming
from the joystick
controller to the
processing circuitry, and
so miscalculate the
correct position of
'Work'. Normally, the
error is no more than a
few tens of microns.
Solution
Flip the appropriate DIP
switches (see the axis guide in
section 2.4). It is not
necessary to restart the
instrument.
Set up the micropipette
alignment again.
Deactivate the 'Z-limit' (press
the 'Z-limit' key once briefly.
The green LED will go out).
Reverse the Y-axis DIP
switch.
Angled micropipettes should
be adjusted from the start so
that they are slightly "toe-
down", in other words, the tip
should touch the bottom of
the microinjection chamber
before the bend does.
Relocate the micropipette tip
and assign a new 'Work'
position.
Avoid violent movements of
the joystick since they not
only confuse the electronics,
they can also damage the
joystick assembly. To ensure
that the 'Work' position is
always current, save a new
one periodically during the
course of an experiment.
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