Lotus TURBO ESPRIT Service Manual page 89

Page 74
SECTION BB
S t r i p p e d Threads
W h i l s t t h e i r o v a l s e c t i o n w i l l p r e v e n t t h e s e bobbins from
t u r n i n g i n normal u s e t h e y may l o o s e n i f t o o much t i g h t e n i n g
p r e s s u r e i s a p p l i e d , o r when an a t t e m p t i s
made t o t a p them
o u t t o a l a r g e d i a m e t e r .
I f
a t h r e a d i s damaged o r s t r i p p e d
an a t t e m p t s h o u l d b e made t o d r i l l t h e t h r e a d c l e a r and u s e
a b o l t and l o c k n u t o r d r i l l o v e r s i z e and f i t h e l i c o i l i n s e r t .
When f i t t i n g an i n i t i a l check should be made w i t h e a c h b o l t
b e f o r e t i g h t e n i n g . Only
U . N . C .
bobbins a r e employed and
p a r t i c u l a r c a r e s h o u l d be p a i d t o f i t o n l y U.N.C. b o l t s t o
them. Where t h e b o l t s a r e p a r t i c u l a r l y t i g h t t h i s may b e
due t o r e s i n w i t h i n t h e t h r e a d e d p o r t i o n o f t h e bobbin which
can be remedied by t a p p i n g o u t .
Only t h e c o r r e c t l e n g t h of t h e b o l t s h o u l d be u s e d , i . e . t h o s e
whose t h r e a d engages w i t h t h e f u l l d e p t h o r t h e bobbin. No
a t t e m p t s h o u l d b e made t o p u l l i t e m s up under heady l o a d w i t h
a s m a l l engagement of t h r e a d . To avoid t i g h t e n i n g up o n t o
t h e p l a i n shank of t h e b o l t i s
i s
recommended t h a t o n l y
s e t s c r e w s be u s e d , i . e . t h o s e t h r e a d e d a l l t h e way up t o t h e
head.
Laminating New Bobbin
F i r s t l y t h e l a m i n a t e s from t h e b a s i c mounting s u r f a c e must
o v e r l a p and i n t e r l e a v e w i t h t h e l a m i n a t e s around t h e bobbins.
Secondly t h e l a m i n a t e must b e w e l l b u i l t up under t h e bobbin
t o p r e v e n t t h e bobbin from p u l l i n g o u t i n a downward d i r e c t i o n .
T h i s s u r r o u n d i n g l a m i n a t e s h o u l d i n i t s e l f comprise a t i g h t
r i n g around t h e bobbin t o p r e v e n t it from b u r s t i n g o u t under
d i a g o n a l l o a d s b u t i f i n doubt one o r two l a y e r s of t a p e o r
c l o t h s h o u l d b e wound round t h e w a i s t of t h e bobbin.
F i n a l l y
p l a s t i c i n e o r s i m i l a r p l u g s s h o u l d b e used d u r i n g l a m i n a t i n g
t o keep t h e r e s i n o u t of t h e bobbin t h r e a d s .
When p r o p e r l y
l a i d t h e v i s i b l e rough s i d e w a l l w i l l b e n e a r l y v e r t i c a l i n
l i n e w i t h t h e bobbin t o p p r o f i l e . I n effect a s t r o n g
r e i n f o r c i n g r i n g of l a m i n a t e s u r r o u n d s t h e bobbin and t h i s
r i n g must b e p r o p e r l y connected t o t h e b a s i c l a m i n a t e .