45
3.
Before removing and replacing X axis bearings, ensure bearings and X axis rail are
completely clean per "Bearing Adjustment" procedure. X bearings rarely need
replacement; most problems are due to dirty bearings or rails. Also check that the nylon
tipped set screws are not sticking. If set screws stick, refer to "Set Screw Adjustment"
section before proceeding.
CAUTIO:
Uneven or excessive pressure on Y axis rail can damage all bearings and possibly
damage the Y axis rail. Proceed slowly and be extremely gentle. Do not drop the
Y rail assembly as mirrors and final focus lens may break.
4.
Remove four 6-32 socket head cap screws holding the X axis front rail to the left and right
side rails.
5.
Loosen the two 4-40 socket head cap screws holding the X axis motor under the front X
axis rail. Hold the motor, then remove the screws. Slide the drive shaft out of the rear
support bearing (see Figure 2) and slide the rear belt off the shaft. Slide the front belt off
the motor end of the shaft then pull the motor cable out of the J-Clips on the front of the
enclosure. Set the motor and shaft down.
6.
Slide the front X axis rail rearward enough (about one inch) to disengage the rear of the Y
axis arm from the rear X rail.
7.
Slide the Y axis arm off of the front X rail and set the front X rail down. Be careful not to
bend or twist the Kapton cable that is still connected to the Y axis arm.
8.
Remove the four white X axis bearings. Check the X axis bearing plate for cracks or
breakage. If the posts that hold the bearings are cracked or broken, the bearing plate must
be replaced.
9.
Install new bearings on posts (pure white side up), put a drop of Locktite 242 on screws,
then snug down screws.
CAUTIO:
Do not tighten bearing screws too tight. Turn the screw to the point where you
can feel it getting snug. Over tightening will break the X axis bearing plate.
10. Slide the Y arm back onto the front X axis rail and hook the rear of the Y arm over the
back X axis rail. Set the front X axis rail on the left and right side rails.
11. Hook front and rear X axis belts on the pulleys of the X motor and shaft. Slide the rear
pulley of the drive shaft into the rear X axis bearing. Locktite the two X axis motor screws
and rehang the X axis motor on the front X rail (do not tighten motor screws yet).
12. Put Locktite 242 on the four 6-32 socket head cap screws and reinstall front X rail.
Tighten the four screws tight.
