Bend Patterns

The following options and additional information are relevant to rectangular bend patterns.

Takeoff Dialog Options Tab

The Takeoff dialog Options tab includes the following options:

Radius Bend: The radius bend pattern has many options that may not be immediately obvious to the user. The following section will explain these options.

Throat Type: There are two options: Mitred or Radius. This determines the throat type of the bend. If Mitred is selected, the throat is made as a straight line between the extensions. The Radius option will create an arc between the extensions.

Note: These options apply only when the bend does not have a zero value in the inner radius field.

Length Adjust For Part 4: This allows the length of the heel wrapper to be adjusted from its nominal value. Enter a positive value for a longer wrapper or a negative value for a shorter wrapper. For square heeled bends this adjust is split equally between each extension; for radiused or mitred heel bends, the whole adjustment is applied to the central or rolled section.

Note: When the bend does not have a square heel, the length of the heel wrapper is automatically adjusted to allow for the extra thicknesses of metal produced by forming the seam. This adjustment is determined by the Folds entry in the Seams database.

Length Adjust For Part 3: This option works in the same way as the Length Adjust For Part 4, apart from the fact that it is applied to the throat wrapper, rather than the heel wrapper.

Vee Notches: There are several Vee Notch options within the Options tab, these controls the vee notches placed in the seam between the body of the bend and the extensions. The male vee notches are applied to the throat only when the throat is not radiused. Other throat options can stop the male vees from being applied.

Vee Depth Male/Female: The user has two options. If Auto is selected the Vee Depth values from the Seams table in the Pattern Database will be used. If a value is entered, this would be applied instead of the Vee Depth values from the Seams table.

Vee Angle Male/Female: This option allows the user to define the angle of the Vee Notch. A smaller angle gives a tighter Vee Notch.

Auto Oversize: This option determines how the cheeks of the bend will be split when they are too large to fit on the sheet. The options are Normal or Radial. If Normal: is selected, the cheeks will be split using horizontal and vertical slices. The Radial option determines that the cheeks will be split using radial slices from the center of the inner radius. This only applies only when the inner radius is non-zero.

Seam Number For Throat: This option allows the user to select a the seam that will be applied to the fitting. If Default: is selected, the throat will use the seam as input on the Connector tab, or the seam set up for Small Throats if applicable. Alternatively, select a specific seam from the drop-down menu.

Leg Lengths: This option allows the overall size of the bend to be entered rather than the length of the extensions. If the overall size is entered the extensions are calculated and displayed in the dimensions. Entering overall sizes allows the inner radius to be modified without altering the size of the bend. The different options are No, Outer, Inner, Center or Width.

• If No is selected, extension lengths are entered.
• The Outer option allows the user to enter outer leg lengths.
• If Inner is selected, the inner leg lengths are entered.
• The Center option allows the centerline leg lengths to be entered.
• If the Width option is selected, the diagonal lengths across the throat and the heel are entered. Note that in this case it is important that the entered values be as accurate as possible, as only certain values can produce a valid bend.

Square Bends

The options for the Square Bend are very similar to that of the Radius bend; however, there are some notable exceptions described below.

3 Parts: This options allows the user to choose whether the part will be made in three pieces, instead of the default four pieces. If No is selected, the cheeks, throat and heel are developed as separate parts. Select Yes and the cheeks and half of the heel are developed together as a single part. The throat and the other half of the heel are developed as separate parts.

2 Part Wrapper: This option controls whether the heel wrapper is made in 1 or 2 parts. If made in 2 parts the wrapper is always sliced at the corner of the bend. If made in 2 parts, the parts will be joined using the seam set up as S2 on the Connector tab. The available options are: No, Yes or Oversize Check.

• If No is selected, the wrapper is made in 1 part; normal oversize options will apply if part is too big to fit on the sheet.
• If Yes is chosen, the wrapper is always made in 2 parts.
• The Oversize Check options determines that the wrapper will only be made in 2 parts, if too big to fit on the sheet when made in 1 part.

Throat Options

The following information on Throat Options is relevant to both Square and Radius Bends.

Small Throats: Sometimes the throat wrapper may be have too small a development to use the default seam applied by the specification. If this is the case, special handling for small throats can be set up. To do this, click File SetUp Pattern Database Pattern Options Alternate Throat Seams, or select the Pattern Database icon from the Utility Bar. When the total throat length (including extensions) falls below the entered value, the entered seam will be used if the angle of the bend is greater than the entered angle. Separate options are available for zero and non-zero throat radiuses. There are also options to remove all vee notches and/or connector notches from the throat when this occurs.