Mumbai University > Mechanical Engineering > Sem 4 > Production Process II

Marks: 10M

Year: Dec 2014

The outside diameter of a circular form tool is determined graphically and will depend on the height of the profile to be turned.

Note: α, ε, γ will be given in question

Steps to design circular form tool.

1) Draw TV off the cut profile of the work piece rotating it 90degree anticlockwise assuming you are on the spindle side of the work piece,

2) Draw FV wherein show circles passing through Rmin and Rmax. Draw axis XX passing through O wherever it intersects the circle corresponding to Rmin and refer it as A and show Dmax (Rmax-Rmin).

3) Draw a line AZ at an angle γ(rake angle) measure (clockwise wrt positive x-axis). Wherever it cuts the circle corresponding to Rmax, Refer it as point B.

4) Obtain point Con line XX such that AC=k Dmax.(k=1.5; chip clearance factor)

5) Draw α line from A (measured anticlockwise wrt to positive x-axis)

6) At C draw a line perpendicular to XX wherever it intersects AZ line, refer it as point D.

7) Bisect angle CDZ and wherever the angle bisector intersects the α line, call that point as F(Centre of form tool)

8) With centre F and radius FA as well as FB draw circles.

9) With F as the centre draw a circle keeping a margin of 8mm from the vertical line passing through C. Show the keyway.

10) Mark points 0, 1,2,3,4,……. on the outline of the work piece in the TV for semicircle divide it into 6 Parts for quarter circle divide into three parts for a straight or taper line define only the end points.

11) Project lines passing from 0, 1, 2, 3, 4……. Up to line XX and number the corresponding points as 0’, 1’, 2’ …………..

12) With O as the centre and radius as 00’, 01’, 02’, 03’… draw the arcs and make it cut the face of the tool AD to obtain points 0’’, 1’’, 2’’, 3’’ …….

13) With F as the centre draw the circles passing through 0”, 1”, 2”………… and mark the corresponding points on section YY.

14) Draw the sectional view (YY section) of the circular form tool to obtain the true shape of the profile. Show reference plane (Rp) in the TV and get the distances of corresponding points from the TV measured with respect to Rp.