Hari, O.K., a little more detail, and some syntax. However, as an aside, I am rather doubtful that you really want to use a Graph to control impeller blade thickness. Your geometry variation is likely to be very smoothly varying and devoid of unusual perturbations which are more in the line of Graph control. I would think that a 2 or 3-section Parallel Blend, a General Blend, a Swept Blend, or a Variable Section Sweep with 2 trajectories, maybe using trajpar without a Graph would be better for your purposes. There have been impeller blades and airplane wings in the Pro/E training courses over the years; maybe you can find one of these in PTC's web files. A good use of a Graph is to control a complex cam surface. Imagine an advancing blade with a flat bottom and undulating top cam surface. We want it to gradually get thicker, smoothly dip down to a low on a curved path, come back up, and level out. The Graph we would use might consist of an inclined line, a spline, and a horizontal line, all mutually tangent. In the simplest case the syntax might then look somethng like this (after pre-creating a Graph feature named THICKNESS): sd3=EVALGRAPH("THICKNESS",trajpar*10) Note the "sd3"; the section dimension is changing as it follows the trajectories of the Variable Section Sweep. Note the arbitrary "10"; this is the full length horizontal dimension of your graph. The EVALGRAPH function "reads" the graph over the span-value occuring after the comma; since trajpar goes from 0 to 1 always, we need to multiply by this number to have the entire extent of the graph covered. More commonly, the equation might look more like this: sd3=2.75+EVALGRAPH("THICKNESS",trajpar*10)/50 The leading edge part thickness is "2.75" and your Graph (sketched using a Sketcher Coordinate System) starts from 0; the values are added together. The "50" occurs because the desired thickness changes are so small relative to the length of the cam that, sketched to scale, the Graph would look like a flat, straight line. So we amplify all desired "real" values by 50 in the graph, and factor the multiplication back out in the equation. Have fun! David
