If you are rolling a ring with a 12 inch od out of 25 inch thick material the mean diameter of the ring will be 11 75 inches.
Calculating a rolling offset in sheet metal.
To calculate r which is the radius of the arc on the neutral axis we can use the following equation.
The length of the material will then be 11 75 x pi or 36 9137 inches.
Air bending one of the three types of bending for sheet metal where the outside mold line is not pressed against the die.
The first number you need to find when calculating a rolling offset is the true offset which is found using pythagoras theorem.
This video goes through the basic steps to calculate a 45 degree rolling offset in a piping system.
In the diagram above the relationship between the travel length and the offsets is as follows.
This is used to calculate the back stop location when working off of a flat pattern.
View the cone instructions below to learn how to manually layout the flat pattern for a truncated cone in single or multiple gore sections.
Step 1 calculating the true offset.
You need to calculate the circumference of the mean diameter of the ring you are rolling.
And by having t and the sheet thickness t we can calculate the k factor as follow.
This simply means that the offset squared plus the rise squared will equal the true offset squared.
It uses two triangles to calculate the travel in the pipe.
This video goes through naming the parts of a piping offset as well as going through a couple examples on how to calculate the offset and the travel in a 45.
Figure 1 upspring or upsweep tools are used to form two bends that are too close together for conventional forming methods.
To calculate the neutral axis distance from the inner face t we can subtract inside bend radius from r.
Figure 3 whether you are using an upspring offset tool left or a.
X squareroot square of v square of h travel t x cos 90 fitting angle run r squareroot square of travel t square of x.
It allows you to determine either the size of raw material needed or the number of gore sections to fit on your available material.
Air bend force chart a chart used to calculate the tonnage required for a bend based on thickness tooling and length.
Figure 2 subtracting the material thickness from the outside dimension gives you the required offset depth a.
