How to Make a Cone (in 6 easy steps)

From the diagram, we have:

• Top diameter ($D_{sm}$) = 3 units
• Bottom diameter ($D_g$) = 7.5 units
• Height = 6 units
• Slant height ($L_{side}$) = 6.406 units

This point is the apex of the full cone from which the truncated cone is derived, and it will serve as the center for drawing the pattern's curves.

The radius of the larger circle corresponds to the slant height from the apex to the bottom edge of the cone, and the radius of the smaller circle corresponds to the slant height from the apex to the top edge of the cone. These circles pass through the top and bottom corners of the original cone outline.

This angle determines the sector of the annulus that will form the cone. The formula provided is:

Now, substitute the dimensions from Step 1 into the formula:

This calculated angle defines the sector you need to cut from the concentric circles.

This material, typically $1/4"$ to $3/8"$, is for the overlap needed when joining the edges to form the cone, often by welding.

This pattern can then be transferred to a material like sheet metal for cutting and forming.

This process is fundamental in sheet metal fabrication, where flat patterns are created to be cut, rolled, and then joined (e.g., by MMAW) to form three-dimensional shapes like cones or frustums.