Chandler 543 - Page 7

MECHANIC INSTRUCTIONS
FIGURE 1
0
TIMING OF TOP INTERMITTENT TENSION
On the top of the machin e th ere are two thread t ens ion ad justment s ••• Rear
T e nsion B and Front Te ns ion A (See Fi gure 1). Rear Tension B is an
intermittent thr ead lo cking t ens ion which lo cks the thr ead prior to the
e nd of each stitch. Thi s pr eve nts the Loop er from s t ea ling thr ead from
Spoo l instead of pulling up the l oop at the end of each stitc h. The
amo unt of tension for l ock ing the thr ead is factory set reasonably tight
by means of Set Screw E (Figure l) therefore, do not dist urb or atte mpt
to utili ze Rear Tension B for adjust in g the n orma l tension expl ained
b elow. However, the time a t which the thread is locked by Tension B
may be adjusted as follows :
Loosen Se t Sc r ew F (Fi gure l) and turn Adjusting Screw G up or down
until Tension B locks the thr ead wh en the Needle Bar has asce nd ed to
within 5/32 of an inch from the top of the Needle Bar s trok e on li g ht
th re a d but l/ 8 of a n inch or l ess on heavy thread.
To prevent thread breakage or ex tr eme ly li ght thread, the Intermittent Ten-
sion s ho uld r elease the thr ead when th e Needle Bar is at l eas t 5/ 32 of
an in ch from th e top of its stroke .
ADJUSTMENT OF NORMAL THREAD TENSION
Tightness of the s tit ch is r eg ulate d by Front Te n sio n A. If the Tension
Adjus tme nt is too ti g ht the Looper will s n ap the t hr ead, if t oo l oose the
knots on the under side of the b utt on will be l oose. Adjus tm ent is made
as fol lo ws :
Turn handwheel at the end of the Mainshaft until Rea r Te n sion B is in
"UP" position. Lower the Button Clamp so the Thread Lock H on the
Face Plate is open (center plun ge r is rele ased ). Pull the thread at the
Need le to be sure it p ull s thru with slight tension. If ten s ion is too
tight or too l oose, turn Tension A up or down until prop er tension is
achieved .
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CHANDLER 5
From the library of: Superior Sewing Machine & Supply LLC