1)
Create a Sphere in Perspective viewport,
from this object we are going to model all
parts of the wheel. Press the F4 hotkey
to make all edges visible.
2)
Rotate it 90º, now we have the direction
of edges favorable to our objectives.
3)
Convert it to Editable Poly, now we are
going to create some new polygons. In Polygon
subobject, select all top center polygons:
4) With Extrude tool, select Local Normal
option at Extrusion Type group. Now specifie
an Extrusion Height to create a superior
layer.
5) From this layer, we are going to extrude
new polygons, creating the conection between
the wheel and the leg.
6) With a square selection of polygons,
make a hole deleting them.
7) Adjuste the format of this hole to be
similar to a circle.
