There
are
few
special
occasions
where
you
will
need
to
redo
the
calibration
or
part
of
it.
●
Firmware
update
-
A
complete
guide
is
in
the
chapter
.
needs
to
be
rerun
otherwise
the
printer
will
show
an
error
message.
● Readjusting
the
PINDA
probe
-
Run
to
store
new
reference
Z
height
values.
It
is
important
to
disconnect
the
printer
USB
from
any
computer
or
OctoPrint
running
on
Raspberry
Pi
for
the
whole
calibration
because
during
the
calibration,
the
printer
will
not
respond
to
any
request
from
a
host
connected
via
USB,
and
communication
will
time
out.
Such
a
time
out
would
cause
the
host
to
reset
the
connection,
causing
the
printer
to
restart
(in
the
middle
of
calibration)
and
it
might
end
up
in
a
weird
state
requiring
6.3.2
Flexible
steel
sheet
surface
preparation
The
MK52
heatbed
has
embedded
high
curie
temperature
magnets.
These
magnets
are
able
to
firmly
hold
removable
spring
steel
sheets.
There
are
two
pins
at
the
end
of
the
heatbed
that
will
align
perfectly
with
cut
out
slots
in
the
spring
steel
sheets.
Make
sure
the
bed
is
clean
and
there
isn’t
any
debris
on
it
before
you
put
on
the
steel
sheet
.
Never
directly
on
the
heatbed.
Pict.
5
-
HeatBed
MK52
base
and
powder
coated
steel
sheet
surface
To
achieve
the
best
adhesion
on
the
new
surface,
it
is
important
to
keep
the
surface
clean.
Cleaning
the
surface
is
very
easy.
The
best
option
is
Isopropyl
alcohol
available
in
drugstores
which
is
the
best
for
ABS,
PLA
and
others
(except
for
PETG
where
the
adhesion
may
be
too
strong.
See
the
chapter
for
instructions).
Pour
a
little
amount
on
unscented
paper
towel
and
wipe
the
surface.
The
bed
should
be
cleaned
while
cold
for
the
best
results
but
it
can
also
be
cleaned
when
already
preheated
for
PLA,
just
be
careful
13