I use this method to make cones of a specific size, I mostly use it to make templates for metal or fabric.

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## Step 1: Draw a Profile of the Cone You Want to Make

Draw a profile of the cone you want to make. I usually use card stock as it is a bit more durable, but use whatever you have around.

## Step 2: Extend Cone, If Needed

If you drew a full cone please disregard

## Step 3: Label Your Cone

Label the base A and B and the apex D. Or not is up to you

## Step 4: Set a Compass

Set a compass to DB

## Step 5: Draw an Arc

Using D as your center, draw an arc from B, make it longer than you might think

## Step 6: Measure AB

Measure AB, mine was 1 3/4

## Step 7: Multiply AB Times Pi

for me this was 1.75x3.14=5.495, I just rounded to 5.5

## Step 8: Measure Arc

You want your arc to be the sum of ABxPi. In my case 5.5 inches, so I use a piece of string to measure it.

## Step 9: Lay String on Arc

Lay string on arc and mark 5.5 inches

## Step 10: Draw Line From Mark to D

For my cone it was from 5.5 along the arc to D

## Step 11: If You Did Not Have a Full Cone

Set compass from D to top of cone

## Step 12: Draw Top Arc

Connect the arc to the line

## Step 13: Cut Out

I used scissors, but use what ever method works for you

## Step 14: Full Cone

here is what a full cone would look like

## Step 15: Truncated Cone

here is the truncated version

## Step 16: Work the Paper

you might have to roll it around a bit to get it into shape. I mostly use for templates for fabric or metal so I dont worry too much at this point

## Step 17: Ta Da

finished

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## 2 Discussions

2 years ago

You got my vote. I have always wanted to know how to calculate cone shapes. Now I know. However I think there is a better way to calculate the shape of the cone than your thread method. While I am happy it works for you, I would have a hard time getting it right myself. Instead I would calculate the shape this way.

I would divide the circumference of the cone base (5.5"") by the circumference of the full circle of radius BD (13.35") and multiply the resulting decimal fraction by 360 thus giving me the angle from BD to the arc to give me the shape of the cone template (148.2 degrees).

Thanks for a lesson on cone making. I will be using this. Be advised that I have voted and Favorited this instructable

2 years ago

Fun idea! I've always liked math equations behind the shapes.