Once you’ve created all the elements, duplicate them and start to combine them as though you’re an engineer assembling a machine. Once you’re happy with a new part, group its separate elements into one symbol, so you can duplicate it over and over.
Remember that Illustrator isn’t a 3D program and it can’t visualise your 3D world automatically, so you need to think it through beforehand. Make sure you avoid impossible 3D shapes as shown above, and make it as realistic as possible.
Now draw a straight line using the Pen tool (P) or Line Segment tool (\), holding Shift to make it horizontal. Then add an Anchor Point (+) in the middle. With the Direct Selection tool (A), drag the Anchor Point to a lower position while holding the Shift key. Then use the Convert Anchor Point Tool (Shift + C) to smooth the corners, naming it ‘Wire_Pattern’. Open the Brushes window and drag ‘Wire_Pattern’ onto it.
In the new window that pops up, select the New Pattern Brush Option, and click OK for everything. Now draw a new straight line, and apply the new brush pattern you’ve just created. Repeat Step 2 to convert it to 3D. As in Step 6, create some bits and bobs for the end of the wire.
With the Rounded Rectangle Tool selected, draw a long shape (66x343 pixels) on the stage, repeat Step 2 to convert it to 3D, set the position as Isometric Right, change the Extrude Depth to 115pt. Click More Options to bring down the Lighting menu and add another lighting source to make it look more plastic and the colours more varied.