TAPER TURNING


  1. TAPER TURNING

1. With The Help Of Compound Slid
2. With The Help Of Tail Stock Off Set
3. With The Help Of Form Tools
1. Compound Rest
Tapered surfaces are turned by swiveling the compound rest to the
required angle α. Before performing the operation, the compound
rest is to be clamped in this position
The tool is feed manually by rotating handle (1). This method is
used for turning short internal and external tapers with large taper
angles, while the work is commonly held in a chuck and a straight
turning tool is used
Taper Calculations
B C
A
L
90° D
D1 2
D L
D
2
tan  1 2
Example 1: Determine the angle at which the compound rest would be
swiveled for cutting a taper on a work piece having a length of 150 mm
and outside diameter 80 mm. The smallest diameter on the tapered end
of the rod should be 50 mm and the required length of the tapered
portion is 80 mm.
Solution
Given data: D1 = 80 mm, D2= 50 mm, L = 80 mm
tan = (80-50) / 280 or = 10.62
The compound rest should be swiveled at 10.62o
Note
If the included angle was given on the drawing,
what is the swivel angle of the compound rest?
Tapers
Expressed as ratio of 1 mm per unit of length
(K)
Work would taper 1 mm
in a distance of 20 mm
ratio of 1:20
Taper Calculations
d = small diameter
k = unit length of taper
l = total length of taper
D = large diameter
If know d, k, and l, D may be calculated. D equal to small
diameter plus amount of taper.
Amount of taper equal to 1/k, so total taper equals l/k.
D = d + total taper
D = d + l/k Or
d= D - l/k
Example 2:
mm
l k
22
20 2
30
60
20
D d

   
 
Calculate the required angle of the compound rest to turn
a 1:30 taper on a work piece 60 mm. The small diameter
of tapered section is 20 mm.
Solution:
Tan α = (22-20)/(2*60) = 0.05
α = 1 deg
2. Tailstock Offset Calculations
x L
2 x
D - d
Offset
l

where D = large diameter
d = small diameter
l = length of taper
L = length of work
The angle of taper α should not exceed 8°. Since the turned surface
is parallel to the spindle axis, the powered feed of the carriage can
be used while the work is to be mounted between centers
Example 3
x L
2 x
D - d
Offset
l

Calculate the amount of setover for a 500mm long guide bar to
turn a 1:50 * 250 mm long taper on a WP. The small diameter of
the taper is 25 mm
3.FORM TOOL METHOD
This Method Is Used In Mass Production For Producing A Small
Length Of Taper.