Garry's Wheel Tutorial

This is a simple step by step guide to modeling an alloy wheel.

This is the wheel we are going to model, it has 5 bolts and the spoke pattern
repeats 6 times - tricky

This is the back of the wheel with the holes modeled and extruded forward. The
orange lines are guidelines that line up with the vertices of the holes.

Draw a curved spline that will be the front surface of the wheel

Add vertices to the line so that they line up with the guides passing through the hole vertices
and other key radius's of the wheel

Duplicate the spline and lathe it around the centre of the wheel, make sure that the
lathe segments correspond to the spoke pattern, the spoke pattern repeats 6 times
so I've used 72 lathe segments.

Convert to a poly object and delete the parts of the wheel that are not required.
This wheel has a spoke pattern that repeats 6 times (every 60 degrees), we only need
to model half of this as it's symmetrical, therefore we can delete all but 30 degrees.

Add a symmetry modifier, you can now see one full 60 degree section of the wheel.

Switch on NURMs smoothing and tweak the vertices so that the curve of the polys matches
the original spline.

Start tweaking the vertices to match the spokes. If you need to move a vert along an edge
make sure that you set the constraints in the 'Edit Geometry' roll out
(make sure you switch it off when you don't need it)
If you want to move a vert left or right a good tip is to rotate the vert around the world axis.

Select the edges around the holes and extrude them back (shift-move)

Start tweaking the back verts so they flare out as they go back,
lots of checking with the source material here.

Select the front edges of the holes and chamfer them (the amount you chamfer them depends
on the style of wheel. After chamfering there will be a few triangle faces, edit these out using the
'Weld' and 'Weld Target' tools.

Continue tweaking and adjusting until you are 100% happy with the shape.
Check it lots of time with the NURMS smoothing on. Then delete the symmetry modifier,
mirror it and weld the two pieces together. Make sure when you weld that you don't spoil
any of the small chamfers

Then duplicate the wheel segment around the center. A good way of doing this is to
set the rotate snap to 60 degrees. If we had five spokes then set it to 72 degrees.

Then start welding the 6 pieces together, again make sure that you don't
spoil any small chamfers.

Unhide the back of the wheel, the next step is to cut the bolt holes in the front
mesh, this is done by hand as a boolean won't work very well and will leave
us with nasty polygons.

Start deleting polys and aligning wheel verts with hole verts, just do this by
eye, none of the snaps will be of any use. Try and keep the number of
triangles to a minimum. Also try and keep the size of the polygons around
the edge a fairly consistent size. In this example the polys at the 1 o'clock
position are a bit too big and the ones at 4 o'clock are too small. This will
affect the chamfers later on.

Join the back and front sections of the wheels together, then use 'Target Weld'
to fix the holes to the front face of the wheel.

Then add a chamfer to the edges, make sure you remove the tiny Triangles.

The centre of the wheel should now look a little like this.

And the final render.