Cone bottoms for tanks

This page is Work In Progress and therefore may not be complete.

This is currently a draft page for JamesRL's scrutiny.

Forget the hole in the top for the time being so, to find length of sloping side ‘L’

Base dia ‘D’ = 570mm (typical for a 205 litre steel drum, but check before proceeding) hence base radius ‘R’ is half this = 285 Desired angle ‘a’, say = 45°

L= R/Cos a L= 285/Cos 45 (Cos being Cosine, available on many calculators or the internet) L = 403mm

To address the hole in the top, use the same formula but substitute the diameter of the fitting you want to use for the base diameter, say 30mm Hence if D = 30, R will = 15

l = 15/Cos 45 l = 21.2mm

We are aiming for this shape to roll into the cone,

so we need to know the angle between the two edges (b°). We’ve already calculated L, 403mm. We know the outer arc length (x) is the same length as the circumference as the drum so we can calculate this using the formula C = π x d, where C is the circumference of the circle

• Steps in producing a cone bottom
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  Blank for cone. Source: Rob-b

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  Arc for cone cut from blank. Source: Rob-b

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  Arc formed to cone and tack welded Source: Rob-b

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  Finished cone with fitting welded to tank. Source: Rob-b