Geometry Lesson

[Lily'sDad]

I want to create a cone out of sheet metal. The cone is 13" high and 13" in diameter across the base. Can anyone tell me how to draw a pattern for it?

 

[Shorty]

Make a circle, 13" radius. On that line, 6.5" x 3.14 should give the base number. To measure along the circle line.

 

[Lance Skene]

For the finished cone to stand 13" tall with a diameter of 13" that circle you draw needs to have approx 14.5 - 14.625 radius.

and the outside perimeter is calculated with 3.14 x the diameter of the circle so 3.14 x 13

trust me... I was a sheet metal fabricator for 30 years... I know a few short cuts..Lol

oh and dont forget too leave a little extra overlap for rivets if thats how your going to join it together... been there

 

[secondtry]

Learn how to layout a cone in sheet metal - Sheetmetalworld
Don

 

[Shorty]

For the finished cone to stand 13" tall with a diameter of 13" that circle you draw needs to have approx 14.5 - 14.625 radius.

and the outside perimeter is calculated with 3.14 x the diameter of the circle so 3.14 x 13

trust me... I was a sheet metal fabricator for 30 years... I know a few short cuts..Lol

oh and dont forget too leave a little extra overlap for rivets if thats how your going to join it together... been there

Uh huh, my figures would give 13 on the slope. Not height.

 

[TAHOE]

Wrap it around your dunce cap??.....

 

[Lance Skene]

Uh huh, my figures would give 13 on the slope. Not height.

only reason I picked up on that is because Ive made the same mistake... more than once Im sure

 

[Lily'sDad]

For the finished cone to stand 13" tall with a diameter of 13" that circle you draw needs to have approx 14.5 - 14.625 radius

How do you arrive at this number?