Question

A shaft of length 90 mm has a tapered portion of length 55 mm. The diameter of the taper is 80 mm at one end and 65 mm at the other. If the taper is made by tailstock set over method, the taper angle and the set over respectively are

• A. 15°32' and 12.16 mm
• B. 15° 32' and 15.66 mm
• C. 11° 22' and 10.26 mm
• D. 10°32' and 14.46 mm

Answer 1

The correct option is A 15°32' and 12.16 mm

Given data:
Shaft length, L = 90 mm
Taper length, l = 55
Big end diameter, D = 80 mm
Small end diameter, d = 65 mm

Half tapper angle:

$tan\alpha =\left(\frac{R-r}{l}\right)=\frac{(80-65)}{2\times 55}$

$\alpha ={7.765}^{\circ }$

$\text{taper angle,}2\alpha ={15}^{\circ }{31}^{\prime }$

$\text{set over, S}=\frac{L(D-d)}{2l}$

$=\frac{90(80-65)}{2\times 55}=12.27mm$