Singer 20U33 - Page 24

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
SETTING:
1. Loosen thread take-up spring regulator set screw.
2. Using a large screwdriver in slot of tension stud, turn stud (at the same
time turning entire tension assembly) either over toward left to lower
thread take-up spring and decrease its 1:novement, or over toward right to
raise thread take-up spring and increase its movement.
3. Securely tighten thread take-up spring regulator set screw.
ADJUSTMENT OF BACKLASH
CHECK:
When zigzag triangular cam gear is properly set in position in relation to
the arm shaft (horizontal) worm gear, there should be a slight amount of
backlash.
Hold ann shaft worm gear immovable by holding machine pulley, and £eel for
backlash by moving zigzag triangular cam sidewise with finger. If there is too
much play and/or not enough backlash, adjust as instructed belo...-.
ADJUSTMENT:
1. Remove two arm top cover screws and lift off cover and loosen zigzag tri-
angular cam shaft set screw. (Fig. 30)
2. While feeling the play between the gears, turn zigzag triangular cam shaft
(eccentric) with a large screwdriver either over toward left (to decrease
backlash), or over toward right (to increase backlash) as required, rmtil
there is just a slight amount of backlash. Then securely tighten set screw.
3. Turn machine pulley and check torque. Also re-check the backlash.
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Fig. 29
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Zigzag Triangular Cam
Shaft Set Screw
Zigzag Triangular Caro
Shaft