If it is causing troubles, which happens sometimes, leave the step off but keep the gap. Then loft or sweep2 between the open trailing edge rails.
This likely has to do with the cross section curves having that little turn at the ends. For a quick solution, I’d also suggest mirroring with a small gap as mentioned and then using BlendSrf to join them.
Hi Dave- I see the sweep falls off the rails in some locations where the rail is a true arc. I’m digging into this more, but that is one thing I’ve found so far.
-Pascal
Hi Dave - see if the attached is anything like what you need. I made these surfaces via sweep2, in sections according to the arcs in the plan curves. I rebuilt one arc- this one was falling off the rails for some reason when the rails was a true arc (this is logged as a bug). Because your plan curves are tangent and not G2, I did not attempt to make the surfaces G2, but a little matchSrf for Tangency here and there between the sections. I did not use any interior curves per section, so that the interpolation could be as smooth as possible - these are on the layer called ‘Extra’ and you can check these against the surfaces to see if you are close enough- Pull the curve to the surface and then CrvDeviation from the original to the pulled curve.
Wing_DD_PG.3dm(448.5 KB)
-Pascal
Hi Pascal,
I appreciate the assistance and tips. It’s been over a month so I’ve finished that wing and got it out the door to the client- I used mainly sweep2 in the end and was able to get a good watertight solid that matched my initial curves within tolerance.
I am still very interested in how to do this kind of thing - both best practice approaches, and also little tips and gems - I’m working on 2 props at the moment (almost done) and have 2 new wings, so any help will be put to good use.
For instance it’s a very good tip to know that sweep falls off the rails on a true arc.
Also using Pull then CrvDeviation - I just tried that and it’s a great technique, will use in future. I hadn’t realised the power/convenience of the Pull command.
Your comments about Tangent vs G2 have set me thinking as well, I’ll question the client in future about whether the wing plan shapes can be altered with the aim of getting G2. I imagine with a faster model plane it would be important for aerodynamics.
Hi Dave- yeah, sorry about the late response- for reasons unknown, to me, but possibly related to density my view of this forum did not tell me about a pretty large number of postings that until the other day- I am pretty sure this is better now, and I’ll be ‘on it’ a little sooner.
As for the the G1/G2… keep in mind that in this case the continuity in question is between surfaces where the edges are parallel to the airflow, so it may be less critical- I have no idea myself, but just sayin’.
The Sweep falling off the rails on arcs is not something I’d count on either way- it appears to be something to watch out for is all- I only saw it on one of the sections I made, but it was pretty far off.
One other thing I’ll mention, just in case- the details at the back of the cross sections include a vertical trailing edge and a fillet between the main surface and the vertical trailing edge- if your series of input curves is scaled as the curves are placed along the rails, this detail will also be scaled- I don’t know if that is good or not, but, it might be better to end all the section curves at the trailing edge, make the trailing edge as a vertical surface and then add the fillet/blend between the two as a separate operation.
-Pascal