Last week we looked at some advanced techniques in 3D. This week I will talk you through some more advanced CAD modeling techniques. In this demonstration, I will create the balusters and newel for a staircase.

A STAIR command is coming to BricsCAD soon, but for now, we shall focus on learning the techniques that will take your CAD modeling to the next level.

Commands covered this week

Use the same settings as week 1.

How to Draw Stairs in 3D

The Balusters

The next phase was making the balusters. I used a photograph of a baluster, traced it, and revolved. Then I aligned the balusters along the stairs.

To do this:

  1. Start by creating a set of step. You can use techniques learnt in the previous blog posts.How to Draw Stairs in 3D advanced modeling techniques
  2. Then import an image into BricsCAD use the Attach Raster Image (IAT) command.
  3. Trace one side using SPLINE.
  4. Next draw a line down the center.How to Draw Stairs in 3D advanced modeling techniques CAD revolve
  5. Finally, use REV – 360°. Use your center line as the axis of rotation.How to Draw Stairs in 3D
  6. Use 3P to draw a line between the end point of the top and middle step.
    Or see last week’s post for drawing on custom user coordinate systems.How to Draw Stairs in 3D
  7. Then, with a little clever geometry and Node Snap, use MOVE to reposition the line to the correct starting point on the first step.
  8. Align the baluster center middle with the endpoint of the 3D polyline.
  9. Then use ARRAYPATH to position the balusters up the staircase.
    The settings I used were: Mode – divide, Items – 8.How to Draw Stairs in 3D advanced modeling techniques CAD

I then repeated for the second half of the staircase.

How to Draw Stairs in 3D advanced modeling techniques CAD

The Handrail

I used EXPLODE (as covered last week) on the array then edited the balusters on the middle step. Afterward, I created a spline along the top of the balusters and swept along the line.

To do this:

      1. Draw a 3D Polyline or Spline along the top points of the balusters.
        How to Draw Stairs in 3D advanced modeling techniques CAD
        You can not fillet 3D polylines, so I used circles. Then trimmed and joined the lines together.
      2. Place a circle perpendicular to the end of the spline.advanced modeling techniques CAD
      3. Use SWEEP.
      4. Select the shape
      5. Hit Enter
    1. Then select the line.
      Tip: for more unusual results try using the twist mode.How to Draw Stairs in 3D advanced modeling techniques CAD

The Newel

To make the newel I used a similar technique to model the balusters. I then extruded rectangles to remove the excess material, chamfered, added columns and applied a twist.

Note: Twist is only available in BricsCAD Mechanical or BricsCAD BIM.

Newel How to Draw Stairs in 3D advanced modeling techniques CAD

To do this:

  1. Create your top and base parts in the same way as the balusters.
  2. Next use EXT Subtract, Both sides.
  3. Apply a chamfer to the hard edges.
    For this example I used a radius value of 20.
  4. Then draw in the columns. Use ARRAYPOLAR to repeat the object 4 times.
  5. Use UNI to create a solid object.
  6. Finally, apply TWIST. Use the centerline as your axis. Place the start and end points of twisting axis between the rectangular portions to prevent the rectangular portions becoming twisted.How to Draw Stairs in 3D Newel advanced modeling techniques CAD

Finishing Up

How to Draw Stairs in 3D advanced modeling techniques CAD

I removed the excess material by drawing the cutting line on to the steps and added wall details. Then I imported the newel and extended the handrail.

advanced modeling techniques CAD

Next time

Join me next week when I make the bathroom. Learn even more advanced CAD modeling techniques.

Don’t have BricsCAD yet?

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Keep Reading

  1. Moving from 2D to 3D CAD
  2. 3D Drawing from engineering plans
  3. Drawing everything but the kitchen sink
  4. More Advanced Modeling
  5. The Shower
  6. The Sink
  7. The Toilet
  8. Walls and Floors
  9. The Roof
  10. Windows and Doors
  11. Create your own components
  12. Rubber Duck
  13. Laser-cut puzzle project

Note: This series is intended as a guide to demonstrate how to use different aspects of 3D modeling tools. It may not always demonstrate the fastest way of getting the result. Keep coming back to see if we cover a faster technique at a later date.