Retsch DM 400 - Manual (Page 45)

Servicing
45
7.
8.
Then hold the motor shaft in place with the help of the motor shaft
retainer (s).
CAUTION!
Do not lock the motor shaft retainer (s) by resting on
the component!
NOTICE!
Hold grinding discs securely when changing them and
do not let them fall. This can lead to breaking or
chipping in the case of zirconium oxide discs.
CAUTION!
Risk of crushing when changing the grinding discs.
Ensure that the grinding disc does not fall on the
floor.
Using the spanner wrench (r), unscrew the hexagon screw on the
moving grinding disc and remove.