Cranked Bar (Lapped Ends)

The Cranked Bar option described in this section applies only to situations where the current bar end is located using the Lapped Bar method.  A separate description is provided below for situations where cranked ends are used in conjunction with the Cover To Face and Leg Length location methods.

Consider the following two bar details.  One detail shows the current bar adjacent to another bar at the same projected centerline.  The other shows the current bar at some considerable offset from the current bar.  The diameter of the current bar is smaller than the existing bar in both cases.

When the two bars in each detail are lapped, they appear as follows:

The Cranked Bar detail is applied in both of these situations using exactly the same procedure.  First, select the Cranked Bar icon as shown:

Bentley Rebar immediately applies the crank to the lapped bar using default crank settings.  These settings are displayed by selecting the Crank push-button (which is now active).  The Crank Settings dialog box appears:

The Leg Length is installed with the same length as the lap entered in the Cover / Length / Lap field (600 in this example).  Notice the Leg length not equal to lap option is turned off by default.  This ensures the leg length at the end of the crank detail is always the same as the lap length.  If the lap length changes sometime later, the leg length also changes provided this option is off.  If you activate the Leg length not equal to lap option you can enter an alternate leg length.  The leg length must then be maintained independently of the lap length.

The initial crank Slope is extracted from your preferred Cranked Bar Slope in your Bar Codes data (refer Chapter 10).  The offset is controlled by the relative offset between the lapped bars, and by your Alignment To Lap setting.

You can adjust any of the crank settings when the dialog is displayed.

In the first example, the slope of the crank is changed to 10.  The Alignment To Lap is also set to "From Outer Edge", ensuring the outside edge of the current bar touches the outside edge of the bar it laps:

The crank is adjusted so the outside edge comes within 20mm (say) of the lapped bar, simply by setting the Offset from lapped bar field to 20.

In this example, however, the only other necessary adjustment is one that switches the side on which the crank is extended.  The Reverse Side toggle button in the Bar End Details box is selected and the adjustment is complete.  The completed bar appears as follows:

In the second example, the offset through which the bar is cranked is much greater.  The crank extension is therefore also much greater assuming the same slope is used.  When the Cranked Bar Settings box appears, the detail is as follows:

Note the default crank slope of 6 is initially too high.  The arrangement is obviously unsuitable.  The overall length of the bar is clearly too small to fit a crank with this slope.  Alignment To Lap is set to "From Centerline" and so the centerlines of each bar are directly in line.  You should enter a value for Offset from lapped bar if the centerlines must be a certain distance apart.  Like the previous example, the Reverse Side toggle button controls the side on which this offset is applied.

Finally, in this example, the slope of the bar is changed to 4 to increase the length of the bar on the right-hand end beyond the crank.  The detail is saved to the design file as:

When the crank dimensions are finalized, Bentley Rebar maintains the crank dimensions (so long as it is physically possible) regardless of the changes made to the ends of the bar.  For example, if cover on right-hand end of the bar (above) is changed, the crank is automatically relocated by the appropriate amount.

The Ticked End and Tagged End options are used in conjunction with a cranked end detail.  Refer to a full discussion of these controls later in this Chapter.