Calculate Flat Pattern for Cone for Sheet-metal Cutting

 How to Calculate Flat Pattern of a Cone for sheet-metal?

Nowadays it’s very easy to find a flat pattern of any shape for sheet-metal cutting by various advanced CAD software like SolidWorks, ProE, etc…

But some of you might be curious to know the calculations behind it in a old fashioned way.

Below are the calculations to cut a profile/flat pattern for bending a cone.

Cone Outline:

Below is the input requirement for calculations:

dB = Cone Bottom Diameter

dT = Cone Top Diameter

h = Cone Height

Calculated Values:

Calculate the below values from the inputs as shown in above figure:

hT = Triangle Height

rH = Radius for Cone Height

r = Pattern Outer Radius

C = Cone Circumference

CT = Total Pattern Circumference

A = Arc Angle

Formulas:

Now calculate the below values based on earlier outputs:

Now you have the desired values required for profile cutting, I have shown the below example with calculations for your reference: