Technical Drawing 2, WASSCE (SC), 2016

Question 1

(1) Two unequal pipes diameter 45 and 60 respectively intersect at 30o as shown above.

Draw, full size, the following:

(a) complete front elevation;

(b) plan;

(c) development of part q with XX as the seam.  

Observation

Candidates were expected to do the following:

A. DRAW THE COMPLETE ELEVATION:

(i) draw two centre lines;

(ii) draw vertical pipe;

(iii) draw slanting pipe q at 300 to the horizontal;

(iv) draw the semi-circle/circle on pipe and divide into 6/12 equal parts;

(v) project lines from the points on the semi-circle/circle parallel to the sides of pipe q.

B. PROJECT THE PLAN:

(i) draw two centre lines;

(ii) draw a circle for the vertical pipe;

(iii) draw the sides of the pipe q on plan;

(iv) draw semi-circle/circle on pipe and divide into 6/12 equal parts;

(v) draw horizontal lines from the points on the circle of pipe q to the circle for the vertical pipe;

(vi) project lines from the end of pipe q in elevation to intercept the horizontal lines on pipe q on plan;

(vii) draw the end of pipe q on plan.

C. CURVE OF INTERSECTION:

(i) project up from the intersecting lines from the circle to the vertical pipe in elevation;

(ii) plot the corresponding points in the elevation;

(iii) join the points for the curve of intersection.

D. DEVELOP PIPE Q WITH X – X AS THE SEAM:

(i) lay out the circumference of pipe q and divide into 12 equal parts;

(ii) draw vertical lines on the division points;

(iii) transfer ordinates from pipe q in the elevation to the development;

(iv) join the points with a curve;

(v) use X – X as the seam.

E. (i) use the correct scale 1:1;

(ii) draw neatly.  

The solution is shown below: