Sketched datum curve tangencies

The part I'm working on has a feature that has an airfoil cross-section profile. The airfoil has been defined as a bunch of points with X-Y coordinates. Since the profile varies along the length of the feature, there are several cross-sections positioned along its length with each having its own set of points defining the airfoil profile at this cross-section. My approach is to create a sketched datum curve at each cross-section using the points and then do a blend or a swept blend (of course, I could try to create section sketches on the fly, but I feel that having them done separately makes my job easier). Now, here is the problem: I've tried creating the curves by sketching a spline and then editing point coordinates manually. I've also tried reading point coordinates in from file. Regardless of the method, there are a couple places in the resulting spline where it is somewhat distorted in comparison to the expected result. The Wildfire Help gives an indication that it is possible to edit tangency conditions at the spline nodes (definitely at the endpoints, and some Help entries seem to indicate that it is possible to do it with intermediate points as well). However, I was not able to find the commands Help advises to use. For instance, here is one Help article: To Modify Tangency Endpoints You can modify the tangency of the endpoints of an existing spline.

1.. Choose Modify > Mod Entity. 2.. Pick a spline. 3.. Choose Tangency from the MOD SPLINE menu. 4.. Pick the start or end point. The system displays the current status of the point (tangent or non-tangent). 5.. The system displays the MOD TANG menu, which has the following options:

a.. Add?Add a tangency condition to the selected point.

b.. Remove?Remove a tangency condition from the selected point.

6.. To modify another endpoint, pick the other endpoint and choose Add or Remove. 7.. Choose Done Modify to exit the MOD SPLINE menu.

See Also

I'd be very grateful if somebody could tell me where these commands are, because so far I have not been able to find them. I am using Wildfire Foundation, and the Help seems to indicate that these commands should be available in the basic package. So far I was able to 'fudge' the splines by adding more points, but I'd prefer to do that by adjusting tangencies, if possible.

: Now, here is the problem: I've tried creating the curves by sketching a : spline and then editing point coordinates manually. I've also tried reading : point coordinates in from file. Regardless of the method, there are a couple : places in the resulting spline where it is somewhat distorted in comparison : to the expected result. : The Wildfire Help gives an indication that it is possible to edit tangency : conditions at the spline nodes (definitely at the endpoints, and some Help : entries seem to indicate that it is possible to do it with intermediate : points as well). However, I was not able to find the commands Help advises : to use.

I can't get into correcting Pro/e's help system. If I were to do that, I'd have to start with scrapping the whole thing, making it a genuine Windows GUI interface, compiled for Windows (see SolidWorks, Pro/DESKTOP) and skipping the typical goofiness.

As for the sketched spline, skip the antiquated help menus. The first thing is to get the start and end points coincident, which can be done the usual way, with the contraints interface. In fact, in mine, when I make them coincident, I'd swear, they're already tangent, even sketching it so that the trailing edge where a sharp intersection matters the least, is that start/end edge. While in sketcher, double click the spline. They seem to become a closed loop. This will bring up a dashboard for spline modification. Pick the 'Control points' radio button to get the control poly to adjust the shape of your spline. Also, a big help ~ turn on the curve analysis with the icon. It's interactive, updates as you drag the control poly, then adjust scale and density to show the shape more accurately.

David Janes