Chain (Mill & Turn)

$image\icon023.gif$

The Chain command will create a single curve by following sequential lines and arcs that are connected (their endpoints coincide). This eliminates the need to select individual geometry points to create the curve.

Procedure 1 : Chaining single Profile (open or closed)

Select Chain command from the Curves menu
Double-click the first element in the "chain" to create the curve.

The nearest endpoint of the closest element is chosen as the starting point for the curve. The chain direction is towards the other endpoint of the selected element. The system automatically completes the curve by following as many connected elements as it can, until there are no more or until a "branch point" is reached. If a "branch point" is reached where the chain could go in more than one direction, you are prompted with "pick next line or arc". The possible elements that could be chosen are highlighted on the screen so that one may be chosen with the mouse. If you wish to end the chain at a branch point, use the Enter key or button. Small gaps in the selected profile are automatically closed based on the Chain Tolerance setting located on the Setup dialog in the View menu. If the double-clicked entity is a circle, the system will internally create two connected 180° arc moves in CCW direction and place the start point at the 0° position.

Click here for graphic Example

Here is an example of chaining a closed profile by "double clicking" the first element of the chain. Note the small arrow at begin of the curve indicating curve direction.

Procedure 2 : Chaining selected Part of a Profile ( from . . to)

Select Chain command from the Curves menu
Select the first element in the "chain" to create the curve.

The nearest endpoint of the closest element is chosen as the starting point for the curve. The chain direction is towards the other endpoint of the selected element. The prompt "pick last line, arc, circle" is then displayed. You must choose the ending point for the curve chain.

Select the last element in the "chain" to close the curve.

The system automatically completes the curve by following the connecting geometry elements form the first point to the last. If you select the same element as first and last, the curve will follow as many connected elements as it can, until there are no more or until a "branch point" is reached. If a "branch point" is reached where the chain could go in more than one direction, you are prompted with "pick next line or arc". The possible elements that could be chosen are highlighted on the screen so that one may be chosen with the mouse. If you wish to end the chain at a branch point, use the Enter key or button. Small gaps in the selected profile are automatically closed based on the Chain Tolerance setting located on the Setup Dialog in the View menu.

Click here for graphic Example

This example explains how to chain an open profile by selecting the first and last element (from . . . to) of the chain. Position the cursor as shown in the graphic below and click on the first element of the profile. Then click on the last element to be chained. The system automatically completes the curve by following the connecting geometry elements form the first point to the last.

$image\curve_chain_from_to_shg.gif$

Procedure 3 : Chaining all Profiles

Select Chain command from the Curves menu
Select the first element on the first profile. This should not be a circle entity since then selection would be limited to circles of same diameter (see 'Chaining Circles' topic below).
Select the first element on the second profile (also no circle entity). If the system detects that the two selected elements are not on the same profile, all profiles are chained in counter-clockwise (ccw) direction.

Click here for graphic Example

Select two separate Profiles

Chained Profiles

Special Case: Chaining Circles

Select Chain command from the Curves menu
Select first circle and last circle in the "chain" to create the curve.

The system connects all circles using rapid moves. The chaining strategy (horizontal, vertical or by distance) is controlled by the Circle Chain setting located on the Setup dialog that can be opened from the VIEW menu.

If the first and last picked circles are a different size then all circles are chained. If the first and last circles are the same size, then all circles of the selected size are chained. In both cases the chaining order is controlled by the Setup - Circle Chain setting.

Click here for graphic Example

The graphic below explains how to chain multiple circles of the same diameter to create a curve to be used with the ‘Contouring’ or ‘Pocketing’ cycle. After selecting the first and last circle to be chained, the system connects all circle entities. Depending on the Rapid Mode toggle, the circles are connected with rapid (default) or linear moves.

Selecting the Circles	Chained Circles linked with rapid Moves

Select two separate Profiles	Chained Profiles