You can make multiple copies of objects using Copy but when the copies repeat in a regular pattern you can use Array to save time.

– for example, you could draw the first thread and use Array to automatically make the remaining threads for the screw below.

Rectangular

A Rectangular Array is a pattern with rows & columns.

– you can specify the distance between rows (vertically) and the

distance between columns (horizontally).

Distances can be positive or negative.

– positive distances correspond to the positive direction of the X axis (distance for columns) & the Y axis (distance for rows).

A Polar Array is a circular pattern about a center point (pole).

  • -you specify the number of items for the number of times the 
selected objects appear in the final array.
  • -the pattern is revolved about a specified center point.
  • -copies are evenly distributed by the same incremental angle through a full circle or you can specify the angle to fill.
  • -arrayed objects are normally rotated as they are copied but you can also force the copies to remain in the original orientation. 

  • The default direction for positive rotation is counter-clockwise.
  • – you must take this into account when the angle to fill is less than 360 degrees (not a full circle).
  • When you use Array for the first time in a drawing session the default method will be Rectangular.
  • You can right-click in the drawing area at the prompt for the type of array to select the Polar method.
  • – then the Polar method will then be the default method (in that drawing session) unless you explicitly select Rectangular again
  • Press <enter> at the type of array prompt to use the <current type>.

  • You can press <enter> when prompted for the number of items in a Polar Array (instead of entering a number).
    1. -if you enter a value for the number of items then you must specify either the angle to fill or the angle between items.
    2. -if you press <enter> (and do not provide the number of items) you must specify both the angle to fill & the angle between items.
  • You can also enter 0 (or press <enter>) at the prompt for the angle to fill
    1. -then AutoCAD prompts for the angle between items.
    2. -you are automatically prompted for this incremental angle if you specify an angle to fill without providing the number of items.
  • If you choose NOT to rotate objects as they are arrayed the results may seem arbitrary but you can influence these results.
    1. -AutoCAD establishes a reference point on the last object 
selected for a Polar Array.
    2. -the reference point depends on object type (e.g. if the object is 
a CIRCLE the reference point is the CIRCLE center).
    3. -arrayed objects are first rotated about the array center point and 
then the rotation is reversed about this reference point.

practice with ARRAY

  1. Close the drawing from the previous exercise if it is open.
  2. Open the T108_7.dwg drawing in your personal folder.

In this exercise you will make an ARRAY using the two rectangles that are currently around the number 1 button of this keypad.

Your drawing will look like this illustration after you complete this ARRAY.

  1. Pick Modify + Array. Use the command line history shown below as a guide to create this array. Note that the distance between rows is negative 0.65.

Command: _array
Select objects : (pick inner rectangle near P1)
Select objects: (pick outer rectangle near P1)
Select objects: ↵
Enter the type of array [Rectangular/Polar] <R>: ↵
Enter the number of rows (—) <1>: 4 ↵
Enter the number of columns (|||) <1> 3 ↵
Enter the distance between rows or specify unit cell (—): – 0.65 ↵
Specify the distance between columns (|||): 0.65 ↵
Command:

If you did NOT enter a negative number for the distance between rows the array will look like the illustration below.

– when you use positive distances the array is generated to the right and upwards.

– the selected objects are the cornerstone for the array in the lower left corner when you use positive distances.

  1. Save this drawing and Close the file.
  2. Open the drawing T108_8.dwg in your personal folder.

In this exercise you will make an ARRAY of the pocket in this indexing table as shown here.

The first pocket is already created and is modeled by a LWPOLYLINE for the outer edges of the pocket and a CIRCLE for the hole passing through the plate.

  1. Pick Modify + Array. Select the LWPOLYLINE near P1 and the CIRCLE near P2 then press <enter> to continue. The command history is also shown.

Command: _array
Select objects: (select LWPOLYLINE near P1)
Select objects: (select CIRCLE near P2)
Select objects: ↵

  1. Type P and press <enter> at the prompt for the type of array to select Polar. Hold your crosshairs over the inner CIRCLE to invoke the Center osnap shown and left-click to use this point as the Center point of array. Enter 8 as the number of items and press <enter> to use defaults for the next two prompts as shown in the command history.

Enter the type of array [Rectangular/Polar] <R>: P ↵
Specify center point of array: (invoke the CENTER osnap shown then left-click)
Enter the number of items in the array: 8 ↵
Specify the angle to fill (+=ccw, -=cw) <360>: ↵
Rotate arrayed objects? [Yes/No] <Y>: ↵
Command:

More practice?

  1. Enter U at the keyboard to undo the last Array.
  2. Pick Modify + Array. This time select ONLY the outer edge LWPOLYLINE near P1 and press <enter> to continue.

  1. Right-click in the drawing area at the prompt for type of array and select Polar in the shortcut menu. (when you used U the method switched back to Rectangular)

  1. Hold your crosshairs over the inner CIRCLE to invoke the Center osnap shown and left-click to use this point as the Center point of array.

  1. Enter 5 as the number of items and use 180 as the angle to fill. Then enter N when asked if you want to Rotate arrayed objects.

Enter the number of items in the array: 5 ↵
Specify the angle to fill (+=ccw, -=cw) <360>: 180 ↵
Rotate arrayed objects? [Yes/No] <Y>: N↵
Command:

AutoCAD rotates the LWPOLYLINE for each copy in the array & compensates by reversing the rotation about a reference point.

– this is done internally so it appears the copies are not rotated. – the reference point is based on the object you selected so the results seem arbitrary.

  1. Enter U at the keyboard to undo the last array.
  2. Pick Modify + Array. Select the LWPOLYLINE near P1 and then the CIRCLE near P2 (you MUST pick the CIRCLE last) then press <enter> to continue.

  1. Type P and press <enter> at the prompt for the type of array to select Polar. Hold your crosshairs over the inner CIRCLE to invoke the Center osnap shown and left-click to use this point as the Center point of array. Enter 5 as the number of items and 180 degrees as the angle to fill. Then enter N when asked if you want to Rotate arrayed objects.

Enter the type of array [Rectangular/Polar] <R>: P ↵
Specify center point of array: (invoke the CENTER osnap shown then left-click)
Enter the number of items in the array: 5 ↵
Specify the angle to fill (+=ccw, -=cw) <360>: 180 ↵
Rotate arrayed objects? [Yes/No] <Y>: N↵
Command:

  • This time the results are what you expected.
  • – the reference point was the center of the small CIRCLE and you controlled this by selecting the CIRCLE last.
  • If the selected object is a BLOCK insert then the reference point is the insertion point of the block
    1. -to have control over the reference point (when you do not rotate arrayed objects) you can make a block insert of the objects.
    2. -select an appropriate insertion point when you define the block.
    3. -blocks are covered in another document later in the course.
  1. Save this drawing and Close the file.