Prismatic shapes are used extensively in construction work. In metalwork, the intersection of a square pipe with a cylinder is often encountered in some construction works. Where a square prism intersects a cylinder, the method of its development is as follows.
Step 1 : The circle of the cylinder is marked full size as shown.
Step 2 : Lay out the image of the square pipe diagonally on the cylinder, and measure the distance marked B on the cylinder.
Step 3 : Spread out the pipe as if it were a fleet sheet, and project from line B on the circle to DB on the flat Sheet.
Step 4 : Divide each side or the pipe into downwards to the face of the circle and to the layout of the pipe. The length of the sheet is the perimeter of the pipe, and should be conveniently divided into four equals parts and latter into four additional parts for each side.
Step 5 : By drawing horizontal lines from the circle from point of intersection of the pipe, the shape of the final cur on the pipe can be traced to each division on the layout development.
Step 6 : Gold on lines D C and B to ensure that the pipe sits on the cylinder.
Step 7 : Mark out point of intersection on the cylinder and cut out the square shape.
