Calculate Step
The function enables you to draw and calculate a stair by supplying the stair equation with the appropriate values. The stair is drawn in the plane where each step and stair direction is defined. All lines belonging to the stair are joined as one object group. You can Control + right-click this group to show the stair in section, elevation, or 3D. The stair calculation enables you to calculate an optimal stair adjusted to the terrain gradient and the natural step length for this gradient.
MOUS_ICO Menu: Landscape > Symbols and objects > Calculate Step
MOUS_ICO Toolbar: Symbols and objects: Calculate Step
The dialog box 'Terrace' will pop up. Select the desired parameters from the dialog box.
Size
Width - Here you can enter the value of the stair width or press the <Point button. The following command will appear Define width: Command prompts for: Pick the first point: Pick the first reference point for the width of the stair. Second point: Pick the second reference point for the width of the stair. If you pick a stair that is too wide, the following message will appear Too wide stair. Define width. Pick the first point: Try to pick the width again. The following minimum and maximum width have been set for the stair Minimum width101 mm Maximum width: 9999 mm If you enter values that are outside this range, you will be requested to enter a new value.
Height - Here you can enter the value of the stair height, or you can press the <Point button and the following command will appear Read stair height from the z-value of drawing elements. First height. Point or Type: Pick the first reference point for the height of the stair. Pick an object in the drawing with z-height or enter the value. 162.500 Second height. Point or Type: Pick the second reference point for the height of the stair. Pick an object in the drawing with a z-height or enter the value. 163.000 The following minimum and maximum heights are set for the stairs: Minimum height101 mm Maximum height: 9999 mm If you fill in values that are not found within this range you will have to re-enter the heights. If you pick a stair that is too tall, the following message will appear: Too tall stair. Further, you will be asked to re-enter / re-pick the heights. Length: Here you can enter the values for the stair Length, or you can press the <Point button and have the following command appear: Define stair length. Pick the first point: Pick the first reference point for the length of the stair. Second point: Pick the second reference point for the length of the stair. If you pick a stair that is too long, the following message will appear: Too long stair. Define stair length. Pick the first point: Try to pick the length again. The following minimum and maximum lengths have been set for the stair: Minimum length101 mm Maximum length: 19 999 meters. If you enter values that are not within this range, you will be asked to re-enter a value.
Gradient - Here you can see the stair gradient calculated on the basis of the height and the length you have entered. If you wish to replace this value you can enter a value yourself and, if necessary, lock it. The gradient is directly connected to the angle and the height is automatically changed if you do not choose to lock the value before editing the gradient. If you do not lock it, the stair length will be altered. The gradient also affects the number of steps, up-steps, and insteps. The following minimum and maximum gradient for the stair has been set: Minimum gradient1:98.99 Maximum gradient: 1:1 If you enter values that are not within this range, you will be asked to re-enter. Angle: Here the angle of the stair is displayed. It has been calculated on the basis of height and length. If you wish to replace this value, you can enter a value yourself and, if necessary, lock it. The angle is directly connected to the gradient and the height is automatically changed if you do not choose to lock the value before you edit the angle. If you do not lock it, the length of the stair will be altered. The angle will also affect the number of steps, up-steps, and insteps. The following minimum and maximum angles have been set for the stair: Minimum angle1° Maximum angle: 89.9° If you enter values that are outside this range, you will be asked to re-enter.
Step length - Here you can have the recommended step length calculated, on the basis of the angle that has been calculated from the height and the length of the stair. If you wish to replace this value, you can enter a value yourself and lock it. Then, the step length will affect the step calculation. The following minimum and maximum step lengths have been set for the stair: Minimum step length101 mm Maximum step length: 1999 mm If you enter values that are not within this range, you will be asked to re-enter. Further, the following table is used to find recommended step length depending on the angle/terrain gradient.
**Terrain gradient**
Terrain angle Ca Step length (cm) 1:5.67 11° 70.0 1:4.7 12° 69.0 1:4 14° 68.0 1:3.5 16° 67.0 1:3 18° 66.0 1:2.5 22° 65.0 1:2.1 25° 64.0 1:1.7 30° 63.0 1:1.4 35° 62.0 1:1.2 41.5° 61.0 1:1 45° 60.0
Stair equation
The equation that is used as a basis for the calculation is Step length = 2 up-steps + insteps. The step length that is calculated is used to calculate the number of steps.
Step calculation
Here you can see which values are calculated for the stair. You can also see that the calculated step length deviates from the equation used for the calculation.
Number of Steps - The number of steps is calculated on the basis of the following equation. The number of Steps = [(2*Stair Height) + (1*Stair Length)] Step The number of steps will be rounded off upwards or downwards depending on the first decimal after the decimal separator. The step length will then change because the number of steps will be an integer and not a decimal number that the step equation may end up with. If you wish to calculate the stair by a particular number of steps, you can lock this value so that up-steps, and steps are adjusted to the length and height you have entered.
Up-steps - Up-steps are calculated on the basis of the following equation Up-Steps = Stair Height Step Number If you wish to calculate the stair by a particular up-step, you may lock this value so that the lowest up-step is changed, picking up the necessary height.
Insteps: Insteps are calculated on the basis of the following equation In-Steps = Stair Length Step Number If you wish to calculate the stair by a particular number of insteps, you may lock this value so that the lowest step is changed, picking up the necessary length.
Calculated step length - Here you can see the step length that will apply for the stair on the basis of the number of steps, up-steps, and insteps that will be calculated or defined.
The lowest up-step - The up-step is calculated on the basis of the following equation. Lowest Up-Step = [(Step Number - 1)*(1*Up-Step)] Lowest instep: The instep is calculated on the basis of the following equation Lowest In-Step = [Length - ((Number of Steps - 1)*(1*In-Step)]
Ok - When you are satisfied with the stair calculation, press ok and the following command for the stair will appear. Starting point: Define the center point of the bottom stair. Direction: Define the direction of the stair from the center point of the bottom stair to the center point of the top stair. The stair will now be drawn on the basis of the parameters that have been calculated.
Next topic: Draw Ramp