How do you connect multiple datum curves on different planes
I am trying to create a 3-D profile consisting of multiple datum curves to use as the trajectory for a sweep. The problem is that I can't seem to connect/attach the different datum curves to form a closed loop needed for the sweep. The series of datum curves are each created in separate operations. After I create a datum curve, I can't snap that datum curve to a previously created datum curve. The part that I am creating is similar to a curved hex wrench.
There are other 'unclean" ways that I could create the part, but I if it could be done with a sweep using a series of datum curves as the trajectory path, this would be much cleaner. The other method would either be a series of protrusions and cuts or merged surfaces and it would be difficult to get what I want.
How do you connect multiple datum curves, created separately to form a closed loop for a trajectory path for a sweep? The datum curves reside in different sketching planes. I have tried a variety of options in datum curves such as composite, etc. The closest I came was using the "Two Points" options allowing me to create a snapped datum curve between two previously created datum curves. But I need to create datum curves with a much more complex profile and this option basically only allowed me to create a straight> line between two curves. There is the "Move Polygon" feature under this option but it didn't help much either.
Does Pro/E even allow what I am trying to do?
There are many ways to achieve what you are trying to do, but probably the method I would use (haven't seen your part, so I'm only guessing) is with the point-to-point curve. Here's how:
1. Create your point-point curve as you did
2. Before attempting to "tweak" it, assign tangency conditions to both ends, using the existing sketched curves as references (there are many tangency options, explore!)
3. Then tweak your curve.
I like to show the curvature plot and inflections with the "Setup Display" option before moving anything
Go into "Move polygon", and choose "View plane" from the "movement Pln" menu. This allows you to move the polygon vertices relative to your viewpoint.
c. Properly tweaking a curve is an iterative process, but the general method consists of doing a rough adjust in the view that makes the most sense (ex. plan view) and then doing a secondary adjust in a view normal to the previous (ex. side view). Only add points (you have to go back from the "control poly" menu) when it's clear that you will never get the shape you want with the endpoints only. Add the points one at a time. The less points the better. It's extremely rare that you'll need more than 3 additional points, and usually you can get away with none.
4. Once you're happy with the curve, you can use it to do anything except a sweep feature ;) The "Sweep" needs a trajectory that has a "normal" reference. A 3D curve has none, so it's an "invalid reference" for a sweep. Usually, a "Pivot Dir Variable section sweep" will do just fine as a surface, but to do a sweep, create a Pivot Dir VSS, and then use the edge of this surface to create your sweep.
To answer your end-of-post question, be assured that Pro/E's Surfacing module can do anything.
It might seem daunting at first, but it is an extraordinarily underrated program.
To me Pro/Surface is what Pro/Engineer is all about... all it takes is patience and determination.