Question 3
Two pipes K and M of unequal diameter intersects at right angle as shown
in Figure 3.
Draw full size the:
- given view;
- plan;
- curve of intersection;
- development of pipe K with X – X as the seam.
Observation
This question requires candidates to draw the curve of intersection of two intersecting cylinders of unequal diameters and the surface development of the accommodating cylinder (the upright cylinder)
The question appears to be unpopular and candidates performed poorly.
Candidates were expected to do the following:
(A)THE PLAN
(i)draw the base circle Ø50 of pipe K;
(ii)draw the sides and end of pipe M Ø30;
(iii)draw the semi-circle/circle at the end of pipe M and divide it into 6/12 equal parts;
(iv)draw horizontal lines from the divisional points to pipe K.
B. THE ELEVATION
- project from the plan to draw the elevation;
- draw the vertical centre line in pipe K;
- draw pipes K and M at right angles;
- draw the semi-circle/circle at end of pipe M and divide into 6/12 equal parts;
- draw horizontal lines from the divisional points to pipe M
CURVE OF INTERSECTION
(i)project lines from pipe K on plan to intercept corresponding horizontal lines in elevation;
(ii)locate the points for the curve of intersection on the front elevation;
(iii)join the points for the curve of intersection.
D. DEVELOPMENT OF PIPE K
1. lay out the circumference of pipe K;
2.locate the position of cut for pipe M on the circumference
and draw vertical lines through the points;
3.draw horizontal lines from the curve of intersection
on pipe M to intersect the corresponding vertical lines;
4.locate the points intersecting pipe M and joining the points for a smooth curve (oval shape).
The solution is shown below:
