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AutoCAD 3D exercise: a bearing block

Model a bearing block in AutoCAD 3D: extrude, unite, then subtract a bore and two bolt holes as cylinders, solved step by step. Practise 3D solids free online.

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Model this bearing block, in millimetres: a base 100 by 60 with corners of radius 10, 12 thick; a boss of 40 across standing 40 high in the middle; a bore of 20 through the boss and two bolt holes of 10 through the base, 76 apart. The base and the boss are extruded from their outlines and united into one solid; the bore and the holes are cylinders subtracted from it.

The drawing

The bearing block in plan, 100 by 60, its boss, bore and holes dimensioned.Ø20Ø40Ø10R101006076
The bearing block in plan, 100 by 60, its boss, bore and holes dimensioned.
The bearing block as a solid, seen from the south-east in the Conceptual visual style.
The bearing block as a solid, seen from the south-east in the Conceptual visual style.

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 plan

On the Outline layer, RECTANG with a Fillet of 10, from 0,0 to 100,60, and a circle at its centre, 50,30, with a Diameter of 40.

1. Draw the plan
  1. Command: RECTANG
  2. Specify first corner point or [Chamfer/Elevation/Fillet/Thickness/Width]: F
  3. Specify fillet radius for rectangles <0.00>: 10
  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)]: 50,30
  8. Specify radius of circle or [Diameter]: D
  9. Specify diameter of circle: 40
1. Draw the plan

2. Extrude the base and the boss

EXTRUDE the outline 12 high, then the circle 40 high: two solids.

2. Extrude the base and the boss
  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]: 12
  6. Command: EXTRUDE
  7. Current wire frame density: ISOLINES=4, Closed profiles creation mode = Solid
  8. Select objects to extrude or [MOde]: 1 found
  9. Select objects to extrude or [MOde]:
  10. Specify height of extrusion or [Direction/Path/Taper angle/Expression] <12.00>: 40
2. Extrude the base and the boss

3. Unite them

UNION: pick both and press Enter. They are one solid.

3. Unite them
  1. Command: UNION
  2. Select objects: 1 found
  3. Select objects: 1 found, 2 total
  4. Select objects:
3. Unite them

4. Draw the cylinders

The bore and a bolt hole as cylinders, with CYLINDER: the bore at 50,30, Diameter 20 and 40 high; a bolt hole at 12,30, diameter 10 and 12 high. Then COPY the hole from 12,30 to 76,0 further on.

4. Draw the cylinders
  1. Command: CYLINDER
  2. Specify center point of base or [3P/2P/Ttr/Elliptical]: 50,30
  3. Specify base radius or [Diameter]: D
  4. Specify diameter: 20
  5. Specify height or [2Point/Axis endpoint] <40.00>: 40
  6. Command: CYLINDER
  7. Specify center point of base or [3P/2P/Ttr/Elliptical]: 12,30
  8. Specify base radius or [Diameter] <10.00>: D
  9. Specify diameter <20.00>: 10
  10. Specify height or [2Point/Axis endpoint] <40.00>: 12
  11. Command: COPY
  12. Select objects: 1 found
  13. Select objects:
  14. Current settings: Copy mode = Multiple
  15. Specify base point or [Displacement] <Displacement>: 12,30
  16. Specify second point or <use first point as displacement>: @76,0
  17. Specify second point or [Exit/Undo] <Exit>:
4. Draw the cylinders

5. Subtract them

SUBTRACT: pick the block and press Enter, then the three cylinders and Enter. The bore and the holes go through.

5. Subtract them
  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:
5. Subtract them

6. Turn the view

-VIEW and SEIso, VSCURRENT and Conceptual, then ZOOM Extents and 0.8x to frame it.

6. 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>: C
  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
6. Turn the view

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