5-7
Maintenance
Figure 5-5. Location of the Brake Spring Wire
from the Ultracentrifuge Bottom
5. Reinstall the stator and brake pin as described under
CLEANING
,
(Steps 8 through 11 of
STATOR ASSEMBLY
), above.
BRAKE SPRING WIRE TENSION ADJUSTMENT
If the brake spring wire is centered but the brake pin drops flat on the
stator, the brake spring wire tension requires adjustment. Adjustment
may also be required if the rotor fails to stop.
1. Remove the brake pin and clean it with alcohol, then reinstall it.
2. Turn the BRAKE TENSION screw (see Figure 5-6) clockwise
(decrease), as viewed from the instrument back, until the brake pin
drops to the stator surface.
3. Turn the screw counterclockwise (increase) one-quarter to one-
half turn until the brake pin pops up to its 3-mm (
1
/
8
-in.) position
above the stator. (The adjusting screw will turn slightly less than
one full revolution from the fully decreased position.) Stop turning
the screw as soon as the brake pin pops up.
4. Lightly touch the pin. If it bounces freely, the brake is in operating
condition. If the pin motion is sticky, remove it and clean the pin
and shaft with alcohol.
