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AutoCAD exercise: a flange

Draw a flange in AutoCAD: a bore with a keyway trimmed into it, eight holes in a polar array, centre lines and diameters, solved step by step. Free online.

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Draw this flange, in millimetres: 140 across, a bore of 60 with a keyway 16 wide whose top is 36 from the centre, eight holes of 14 on a pitch circle of 110, and its centre lines. The keyway is a rectangle trimmed into the bore; the holes are one circle and a polar array.

The drawing

The flange, 140 across, with its keyway, eight holes and diameters.Ø60Ø14Ø110Ø14016
The flange, 140 across, with its keyway, eight holes and diameters.

Step by step

The engine draws each step and writes its history as you would type it: the prompts in AutoCAD 2027's order, with the same option letters. After a command's first point, a typed point is measured from the last one, as dynamic input measures it, and the history writes it with @; # measures from the origin.

1. Draw the circles

On the Outline layer, two circles at 0,0, each by its Diameter: 140 and 60.

1. Draw the circles
  1. Command: CIRCLE
  2. Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: 0,0
  3. Specify radius of circle or [Diameter]: D
  4. Specify diameter of circle: 140
  5. Command: CIRCLE
  6. Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: 0,0
  7. Specify radius of circle or [Diameter] <70.00>: D
  8. Specify diameter of circle <140.00>: 60
1. Draw the circles

2. Cut the keyway

RECTANG from -8,20 to 16,16 further on: it crosses the bore. TRIM cuts an object where the others cross it: pick the bore's arc between the rectangle's sides, then the rectangle's bottom, inside the bore. What is left is the keyway, its two sides and its top.

2. Cut the keyway
  1. Command: RECTANG
  2. Specify first corner point or [Chamfer/Elevation/Fillet/Thickness/Width]: -8,20
  3. Specify other corner point or [Area/Dimensions/Rotation]: @16,16
  4. Command: TRIM
  5. Current settings: Projection=UCS, Edge=None, Mode=Quick
  6. Select object to trim or shift-select to extend or [cuTting edges/Crossing/mOde/eRase]:
  7. Select object to trim or shift-select to extend or [cuTting edges/Crossing/mOde/eRase/Undo]:
  8. Select object to trim or shift-select to extend or [cuTting edges/Crossing/mOde/eRase/Undo]:
2. Cut the keyway

3. Array the holes

A hole on the pitch circle: a circle at 55<22.5, 55 from the origin at 22.5°, with a Diameter of 14. ARRAYPOLAR: pick it, press Enter and give the centre, 0,0; ASsociative and No leave eight separate circles, which a dimension can pick, and Items, 8, spreads them round the whole circle. Then, on Centre lines, the pitch circle at 0,0, its diameter 110.

3. Array the holes
  1. Command: CIRCLE
  2. Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: 55<22.5
  3. Specify radius of circle or [Diameter] <30.00>: D
  4. Specify diameter of circle <60.00>: 14
  5. Command: ARRAYPOLAR
  6. Select objects: 1 found
  7. Select objects:
  8. Type = Polar Associative = Yes
  9. Specify center point of array: 0,0
  10. Select grip to edit array or [ASsociative/Items/Angle between/Fill angle/ROTate items/eXit]<eXit>: AS
  11. Create associative array [Yes/No] <Yes>: N
  12. Select grip to edit array or [ASsociative/Items/Angle between/Fill angle/ROTate items/eXit]<eXit>: I
  13. Enter number of items in array <6>: 8
  14. Select grip to edit array or [ASsociative/Items/Angle between/Fill angle/ROTate items/eXit]<eXit>: X
  15. Command: CIRCLE
  16. Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: 0,0
  17. Specify radius of circle or [Diameter] <7.00>: D
  18. Specify diameter of circle <14.00>: 110
3. Array the holes

4. Draw the centre lines

Still on Centre lines, two lines with LINE through the centre, 156 long: from -78,0, 156,0 across; from 0,-78, 0,156 up.

4. Draw the centre lines
  1. Command: LINE
  2. Specify first point: -78,0
  3. Specify next point or [Undo]: @156,0
  4. Specify next point or [Undo]:
  5. Command: LINE
  6. Specify first point: 0,-78
  7. Specify next point or [Undo]: @0,156
  8. Specify next point or [Undo]:
4. Draw the centre lines

5. Dimension it

On Dimensions, DIMDIAMETER on the bore, a hole, the pitch circle and the outline, each picked where no dimension crosses it yet, then DIMLINEAR across the keyway's top: 16.

5. Dimension itØ60Ø14Ø110Ø14016
  1. Command: DIMDIAMETER
  2. Select arc or circle:
  3. Dimension text = 60
  4. Specify dimension line location or [Text/Angle]:
  5. Command: DIMDIAMETER
  6. Select arc or circle:
  7. Dimension text = 14
  8. Specify dimension line location or [Text/Angle]:
  9. Command: DIMDIAMETER
  10. Select arc or circle:
  11. Dimension text = 110
  12. Specify dimension line location or [Text/Angle]:
  13. Command: DIMDIAMETER
  14. Select arc or circle:
  15. Dimension text = 140
  16. Specify dimension line location or [Text/Angle]:
  17. Command: DIMLINEAR
  18. Specify first extension line origin or <select object>: -8,36
  19. Specify second extension line origin: @16,0
  20. Non-associative dimension created.
  21. Specify dimension line location or [Text/Angle/Horizontal/Vertical/Rotated]:
  22. Dimension text = 16
5. Dimension it

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