A Piston, like the one shown in the 3D graphic on the right, is often found in machines - Leaving Cert DCG - Question C-4 - 2014

Draw a circle centered at point O with a radius equal to the length OP. This circle represents the path that point P will take as the crank rotates.

Divide the circle into equal sections, such as 10-degree increments, to assist in establishing the positions of point P as it rotates around O. Label these points clearly.

For each division, draw the connecting rod PR extending at an angle from the end of OP. This will create multiple positions for point R along the horizontal axis.

Mark the location of point Q for each position of the connecting rod PR. Q will be constructed based on the angle and length from O to P to the position of R.

Connect the marked points of Q to visualize the locus traced by point Q as the crank rotates. This should create a smooth curve that represents the path taken by Q.

Illustrate the top view of the helix moving from point S to T, ensuring to include any necessary projection lines to aid in understanding the heights and angles involved.

Create the outline elevation of the helical sculpture, showing sequential points of elevation as the helix ascends from point S to point T.

Incorporate horizontal divisions within the elevation to show varying heights of the helix at different segments from S to T.

Ensure that projections from the top plan view accurately correspond to their respective height in the elevation view, depicting how the helix spirals upwards.

Identify and mark all significant points on the elevation view, including where the helix intersects with the cylinder.

Sketch the actual representation of the helical structure in the elevation based on the projected points and heights. Maintain a consistent spiral nature in the drawing.

Ensure that the final drawings are neat, well-labeled, and clear. Use proper line weights and styles to enhance understanding and visibility of the diagrams.