Duff-Norton SK6420-6 - Manual (Page 9)

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12. Attach red terminal wire (17) to common terminal of
left side switch (16). Attach blue terminal wire
(18) to common terminal of right side switch
(16). Feed ends of terminal wires (17) and (18)
through 5/8" dia. hole into cover (9) capacitor
box.
13. Press wiper scraper seal (60) into guide bushing (59)
and thread guide bushing into outer tube (55).
(Scraper part of scraper seal should be facing
outward away from guide bushing.)
14. Assemble stop disc (69), lock washer (70) and cap
screw (71) to ball screw (62).
15. Remove binding wire, clamp or tape securing ball nut
(64) to arbor, slide arbor with ball nut, thread
end first, onto gear end of ball screw (62), hold
against shoulder and thread ball nut onto ball
screw.
16. Thread coupling (72) onto translating tube (66).
17. Fill the translating tube (66) approximately 1/2 to 3/4
full with Exxon Ronnex Extra Duty #1 (no
substitutes).
18. Slide translating tube (66) and coupling (72) over ball
screw (62) and thread coupling onto ball nut
(64).
19. Spot drill through threaded holes in coupling (72) into
translating tube (66) and ball nut (64), remove
drill chips and install set screws (65).
20. Assemble washer (44) and gear spacer (43) on ball
screw (62). Install key (40) in key groove of ball
screw.
21. Clamp sides of housing (42) in vise (use soft jaws
with input pinion up).
22. Install screw (62) - gear spacer (43) - washer (44) -
translating tube (66) - and ball nut (64)
assembly into housing (42) through bushing
(34).
23. Apply a generous amount of Exxon Ronnex
Extra Duty #1 (no substitutes) to thrust washers
(35) and thrust bearing (36) and assemble over
gear spacer (43).
24. Aligning keyway in output gear (39) with key (40) in
screw (62), assemble output gear (39) on ball
screw (counter-bore in gear facing up away
from thrust bearing).
25. Clamp screw (62) between soft jawed vise. Thread
spacer nut (37) on ball screw (62) and tighten
against output gear (39). Spacer nut flange
should be in counterbore of output gear. Do not
grip on bearing journal of spacer nut when
tightening spacer nut.
26. Check alignment of tapped holes in spacer nut (37)
with holes in output gear (39). Use two 9/64
CAUTION
When using replacement parts, make sure you have
correct spring. (Part No. SK-6415-18). Red spring
designates DC unit. If your replacement spring is red,
contact your local distributor or the Duff-Norton Factory
for immediate replacement.
b. Install spring (49) into insert (51) pocket
(chamfered end).
c. Align pinion coupling (47) and spring (49) as
shown in Figure 6-1A and press insert (51) and
spring (49) assembly into housing (42)
(alignment must be as shown in Figure 6-1A).
7. Press bushing (34), bushing (6) and flange bearing
(25) into cover (9).
8. Assembly of Limit Switch Components (refer to
Figure 6-3).
a. Assemble insulation (19), limit switch (16)
and screws (15) on limit switch bracket (21).
NOTE
Limit switch (16) leafs should face each other. Insulation
(19) should be folded up and behind common terminal of
switches (16). See Figure 6-3.
b. Assemble limit switch nuts (23) on limit
switch shaft (22) (care should be taken not to
cross-thread nuts). Nut hubs should be facing
away from each other. See Figure 6-3.
c. Assemble worm (24) on limit switch shaft
(22). Unthreaded hub on worm should be away
from limit switch shaft (22) threads.
See Figure 6-3.
9. Assembly of Limit Switch Components in cover. Refer
to Figures 6-2 and 6-3.
NOTE
Cover (9) should be in a soft-jaw vise with limit switch
box cover up.
10. Assemble limit switch bracket (21) - insulation (19)
- switch (16) assembly into cover (9) with
screws (20).
11.Assemble limit switch shaft (22) - limit switch nuts
(23) - worm (24) assembly into cover (9).
Tilt shaft and insert into I.D. of bushing (34).
Then straighten and assemble shaft into flange
bearing (25).
NOTE
Worm (24) should be facing up toward flange bearing
(25). See Figure 6-3 (shaft will be loose in cover).
DN-SK6420-6-1006 10/10/06 11:40 AM Page 9