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AutoCAD 3D exercise: a mounting plate

Model a mounting plate in AutoCAD 3D: regions, a subtraction for the holes and one extrusion make the solid, solved step by step. Practise 3D free online.

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Model a mounting plate 10 thick, in millimetres: its outline 100 by 60 with corners of radius 8, and four holes of 10 whose centres are 15 from the edges. It starts flat. The outline and the circles become regions, the holes are subtracted while the plate is still flat, and one extrusion turns it into a solid with its holes.

The drawing

The plate's outline, 100 by 60 with four holes, dimensioned.Ø10R8100607030
The plate's outline, 100 by 60 with four holes, dimensioned.
The plate as a solid, 10 thick, seen from the south-east with hidden lines removed.
The plate as a solid, 10 thick, seen from the south-east with hidden lines removed.

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 profile

On the Outline layer, RECTANG with a Fillet of 8, from 0,0 to 100,60. Then a circle at 15,15 with a Diameter of 10, and COPY it from its centre to 70,0, 70,30 and 0,30.

1. Draw the profile
  1. Command: RECTANG
  2. Specify first corner point or [Chamfer/Elevation/Fillet/Thickness/Width]: F
  3. Specify fillet radius for rectangles <0.00>: 8
  4. Specify first corner point or [Chamfer/Elevation/Fillet/Thickness/Width]: 0,0
  5. Specify other corner point or [Area/Dimensions/Rotation]: @100,60
  6. Command: CIRCLE
  7. Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: 15,15
  8. Specify radius of circle or [Diameter]: D
  9. Specify diameter of circle: 10
  10. Command: COPY
  11. Select objects: 1 found
  12. Select objects:
  13. Current settings: Copy mode = Multiple
  14. Specify base point or [Displacement] <Displacement>: 15,15
  15. Specify second point or <use first point as displacement>: @70,0
  16. Specify second point or [Exit/Undo] <Exit>: @70,30
  17. Specify second point or [Exit/Undo] <Exit>: @0,30
  18. Specify second point or [Exit/Undo] <Exit>:
1. Draw the profile

2. Make regions

REGION turns closed objects into regions: pick the outline and the four circles, then Enter. Five loops, five regions.

2. Make regions
  1. Command: REGION
  2. Select objects: 1 found
  3. Select objects: 1 found, 2 total
  4. Select objects: 1 found, 3 total
  5. Select objects: 1 found, 4 total
  6. Select objects: 1 found, 5 total
  7. Select objects:
  8. 5 loops extracted.
  9. 5 Regions created.
2. Make regions

3. Subtract the holes

SUBTRACT: pick the plate's region and press Enter, then the four circles' regions and Enter. One region is left, with four holes in it.

3. Subtract the holes
  1. Command: SUBTRACT
  2. Select solids, surfaces, and regions to subtract from ..
  3. Select objects: 1 found
  4. Select objects:
  5. Select solids, surfaces, and regions to subtract ..
  6. Select objects: 1 found
  7. Select objects: 1 found, 2 total
  8. Select objects: 1 found, 3 total
  9. Select objects: 1 found, 4 total
  10. Select objects:
3. Subtract the holes

4. Turn the view

-VIEW and SEIso look at it from the south-east and above; VSCURRENT and Hidden hide what faces hide. The ViewCube turns the view with a click too.

4. Turn the view
  1. Command: -VIEW
  2. Enter an option [Orthographic]: SEI
  3. Regenerating model.
  4. Command: VSCURRENT
  5. Enter an option [2dwireframe/Hidden/Conceptual] <2dwireframe>: H
4. Turn the view

5. Extrude it

EXTRUDE: pick the region, press Enter and type the height, 10. The plate is a solid, holes and all. ZOOM Extents frames it, and a scale of 0.8x leaves room round it.

5. Extrude it
  1. Command: EXTRUDE
  2. Current wire frame density: ISOLINES=4, Closed profiles creation mode = Solid
  3. Select objects to extrude or [MOde]: 1 found
  4. Select objects to extrude or [MOde]:
  5. Specify height of extrusion or [Direction/Path/Taper angle/Expression]: 10
  6. Command: ZOOM
  7. Specify corner of window, enter a scale factor (nX or nXP), or [All/Extents/Previous/Scale/Window/Object]: E
  8. Command: ZOOM
  9. Specify corner of window, enter a scale factor (nX or nXP), or [All/Extents/Previous/Scale/Window/Object]: 0.8x
5. Extrude it

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