For  example,  if  a  taper  6"  long  with  diameters  of  2^"  and  2"  respec-
tively is  to  be  turned  on  a  bar  18"  long,

0  =  (D  ~  O  L  -  (2?  ~  2)  x  18//  =       18"       =3"
21  2x6          ~2x2x6~4*

c.  When  part  of  a  bar  is  to  be  tapered  to  a  given  T.P.F.,


For  example,  if  a  T.P.F.  of  0.6"  is  to  be  turned  on  a  bar  12"  long,
0  =  2^  (T.P.F.  x  L)  =  ^  x  0.6  x  12"  =  0.3".
,-'         '£V

rUTTT>XFTArr«  •

a

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TAPER

2.  By  using  the  taper  attachment  shown  below,   which
causes  the  tool  to  feed  transversely  at  the  same  time  that  it


TAPER   ATTACHMENT

The  graduations  on  the  ends  E,  E  are  in  T.P.F.,  and  C  is  attached  to  the  cross

slide  of  the  lathe.   The  graduations  at  one  end  are  usually  in  tenths  and  at  the

other  end  in  eighths

feeds  longitudinally,  thus  turning  a  taper.  This  attachment
can  be  used  for  turning  either  ex-
ternal or  internal  tapers.  In  using
a  taper  attachment  neither  the  tail-
stock  offset  nor  the  distance  between
centers  need  be  considered.
3.  By  using  the  compound  rest,
one  form  of  which  is  here  shown.
Since  the  tool  can  be  set  at  any


COMPOUND    REST

The  base  G  is  graduated  in
degrees


desired  angle,  very  steep  tapers  can  be  cut  with  the  compound


METHODS   OF   GRADUATING   THE   BASE   OF   A   COMPOUND  REST
The  line  A-B  represents  the  center  line  of  the  lathe

rest.    The  base  of  the  rest  is  usually  graduated  in  degrees  in
one  of  the  four  ways  shown  in  the  figure  above.
The  method  of  setting  the  compound  rest  is  described  on  page  28.
