how to model piston head in creo 3.0?
here it is read description for clear overview...:)
create extrude of required dimensions
shell the part with required thickness
create datum plane parallel to front plane
draw a line parallel to extruded feature in front view
project the line onto the surface
sweep the line and give the piston ring groove depth by specifying in the sketch of sweep by specifying the dimension of rectangle (better use center rectangle) and just pattern the groove with dimensional pattern and add no. as 3
now draw a spline on datum plane and project the spline so that it becomes closed loop
sweep the line so that it should remove the whole material below the part
now select the front plane and sketch a hole.
extrude the hole symmetrically and remove the material.thus the required part is obtained