Inclined Square to Round development

What it is

The square-to-round transition with the circular opening tilted relative to the base and centred over it. It keeps the triangulated construction of the concentric transition: the part is symmetric about the plane through the axis and the line of steepest tilt, so the pattern develops half of it and mirrors that half.

Where it is used

Connections between equipment and pipework arriving at an angle, hoods with a tilted outlet, adaptations in existing installations where the duct cannot be plumbed.

Measurements the calculation needs

• H Height to the centre of the mouth
• D Diameter of the round mouth
• X Side of the square base
• ANG Tilt of the round mouth
• DV Divisions
• THK Plate thickness

Worked example

The values the form comes pre-filled with, run through the tool itself:

Height to the centre of the mouth	1000 mm
Diameter of the round mouth	800 mm
Side of the square base	1400 mm
Tilt of the round mouth	30°
Divisions	16
Plate thickness	3 mm
The flat pattern fits a plate of	3553 × 2014 mm

Result of the example

Plate	3553 × 2014 mm

Guides about this part

• Square to round transition: development by triangulation, step by step

Frequently asked questions

When do I need this instead of rectangle to round?

When the round opening is not square to the base. If it is, the concentric transition is simpler and easier to form.

Can the round opening sit off the centre of the base?

Not in this part: it tilts about the centre of the base. An opening that is offset as well as tilted is a different part, with a different pattern, and is not in Planichapa yet.

What is the angle measured against?

The perpendicular to the base: the larger the angle, the more the round opening lies over. The angle has to be greater than zero -- at zero the opening is square and the part is the concentric transition, which exists on its own.