Car Tutorial Part 6 - Wheel openings, Rims and Tires continued

Ed Ferguson, CascadiaDesignStudio.com

Wheel Nuts:
Draw a 0.25” radius circle and duplicate. Draw a hexagon, apply a small Fillet, and duplicate. Arrange as follows and Loft the four profile curves using Style = Straight with Cap Ends.

Fillet the front face and hex edges 0.05”. It’s not a totally accurate model of a nut, but good enough for the zoom level I expect to render.



Position the nut over the pocket.



In side view, hide the wheel and check the depth of the nut in the pocket.



Array > Circular the nut with Item Count = 5.



Draw the profile for the tire. I added notches (see inset picture). The notches will define unique surface areas so I can assign a unique material to the tire tread, the tire corners, and the sidewalls.



Revolve the blue tire profile using the wheel center line as the revolve axis points.
Assign a unique Style to the tire tread, the tire corners, and sidewalls. Select the entire tire and Join to create a Solid.

Next we’ll add three raised areas on the tire sidewalls. Draw a profile curve as follows and position it on the tire. Notice I picked a random location that does not align with any of the spokes. This will produce a more natural render as opposed to making them align.

Circular Array to produce three. Transform > Project the three curves onto the sidewall.



Select the tire and Trim using the three projected curves as the cutting object. Assign a unique Style to the resulting three surfaces. Select the entire tire and Join to create a solid.

Select the three purple surfaces and (using side view) Extrude them 0.05”. Select the entire tire and Join to create a solid.



At this point we should have two solid objects – a solid rim and a solid tire.

You could model the tire tread per this tutorial:
http://moi3d.com/forum/index.php?webtag=MOI&msg=5470.1
Modeling tire tread will greatly increase file size. So instead, I’ll use two tire tread bump maps in my render program – one for the main tread and one for the corner tread. Bump maps also allow you to easily try differed tread patterns.