Singer 620 - Setting Com-Selector-Arm Stops

CAM STACK (Cont’d.)
Setting Cam-Selector-Arm Stops
Remove arm top cover.
Check adjustment of worm wheel shaft (see in¬
struction on page 17).
Set selector at “D" and “L 1 * .
Turn hand wheel over toward operator until arm-
bracket followers rest upon high points of bottom
(zigzag) cam of cam stack.
At this setting, when stitch pattern selectors are
depressed as far as possible, clearance between
both followers and high point of bottom cam should
be 0.010 and 0.012 inch.
Front Selector-Arm Stop
Disengage release mechanism by pushing in on
upper selector button.
Loosen screw in front selector-arm stop and de¬
press top selector button until there is approximately
0.010 inch clearance between front follower and cam.
Maintain this clearance while moving stop toward
front of machine until it makes contact with front
selector-arm. Then tighten screw securely.
Rear Selector Arm Stop
Loosen stop-bushing set-screw at rear of cam-
selector arm-shaft. ?-ess lower selector button until
there is ccDroximateiv 0.010 inch clearance between
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rear - o l .ewer-arm, men rignten set screw securely.
Aligning Indicator with Selector Letters
Indicators “A” to “J”
Loosen set screw through hole in upper selector
arm.
Align indicator mark with “A” position on front
panel, making sure that rear follower is in contact
with aluminum bight-control ring (lowest ring with
largest diameter under the cam stack). Tighten set
screw securely.
Indicator “K” to “Special”
Loosen hex head screw in front follower arm.
Align indicator mark with ”K” position on front
panel, making sure that front follower is in contact
with aluminum bight-control ring (third ring from bot¬
tom under the cam stack). Then tighten hex head
screw