Firepit Design Exercise
Master use of the ARRAY command to facilitate design tasks using
Many design tasks require that some form of repetitive pattern of features be
created. The array command allows users to rapidly copy objects in either
rectangular or polar patterns. Tools such as ARRAY and MIRROR make designing
objects with symmetry much easier. It is important when drawing, modeling, or
designing anything to make note of any symmetry in the object before you start
in order to create it in the most efficient manner possible.
I had to do this design task with my dad when I was about 10 years old. I
still have some of the extra bricks (we bought way too many). All we had then
was a slide rule...
In mechanical design polar patterns are common in objects that rotate such as
gears, wheels, fans, pipe flanges.etc. The application of rectangular patterns
are just as numerous in all forms of designs.
Relevant Pages in Text:
Open the drawing file
You will see a representation of a concrete patio with a 37" diameter hole in
it. The hole is for a fire/BBQ pit with a 36" diameter grill in its center. The
grill is mounted on a threaded shaft that allows it to be raised and lowered by
To complete the installation we need to border the pit with bricks.
- The bricks must be of a standard shape available at a typical building
- The minimum space between bricks should be less than 1"
- The bricks must not overlap
SUGGESTED DESIGN PROCESS
- Determine the size of the bricks you intend to use (use web sites below
or go measure one outside)
- Draw the first brick at an appropriate location at the edge of the
firepit without intruding into the 37" diameter hole
- Extrude the brick into a 3D solid
- Use the array command to complete the pattern around the pit to meet the
design criteria above
To complete this assignment:
- Annotate the drawing with a note stating the number of bricks
- Place dimensions on the drawing to show the size of the brick, the angle
between bricks, and the distance at the closest point between bricks
- Use Cross-Hatch with the predefined 'GRATE' pattern to represent the
- Create a drawing layout that shows a top view looking down at the patio
showing the dimensions zoomed in to show just the firepit, border and
- Generate an isometric view in another layout showing the 3D Shaded view
of the layout
- Use a standard scale for the view with the dimensions in it and create a
note in the layout PAPERSPACE that specifies the scale of the viewport
with the annotation
- Copy both drawings into your PowerPoint portfolio
For Advanced Users:
- Try the 3DARRY command. How is it different than the 2D version.
- If the firepit were rectangular or diamond shaped could we still use the
array command to help design the border.
Other Relevant Resources on the Web:
Online Tutorials For Array:
copyright (c) 2008 S. B. Egli