OpenVSP Tutorial: A Better Export for CAD
HTML-код
- Опубликовано: 20 авг 2024
- The OpenVSP File--Export... menu item to export to a STEP format CAD file does not always create a good file. As an example the FreeCAD program does not read the exported CAD file correctly. There is a better way. The Analysis--Trimmed Surfaces... menu item produces a far better STEP file (or IGES format file).
In this video we show an example of the better export mechanism and also show the "Negative Volume" option on the "Gen" tab of the Geometry dialog.
Links:
RUclips Channel: / @designer103
Aero Terminology Playlist: • Aero Terminology
UWS-1 Ultralight Design Playlist: • UWS-1 Design
Patreon: / ultralight_airplane_wo...
Facebook: / ultralightairplanework...
Website: www.Ultralight...
Aero Design Terms and Resources: www.Ultralight...
Disclaimer: If you use any of the information that you see on this video on a project of your own, YOU become the engineer and responsible party for your project. It is possible that miscalculations were made in the production of this video. Since you are now the engineer for your project, you must verify the information that you use.
You have no idea how impotant this video was for me.
♥♥♥♥♥♥♥♥
Rather than struggle against Shown / No Shown all the time, you should experiment with using Sets. You can create a Set that contains just the components you want for a given analysis or export and then pick that from the corresponding menu.
You are absolutely right. I really should use sets more often.
Absolutely brilliant work. This saved me a lot of time.
I just spent a very long time trying to reproduce what is shown in the video, using v3.25.0. I eventually realized that it was trying to export EVERY body in the scene no matter what. In the cases that I let it finish, this took an extremely long time and in every case produced a file that caused Freecad to crash when importing.
For anybody else having this problem, maybe try this approach: save the file, delete everything you don't want to export, then do the export, then re-open the file. This will still not help if some of your bodies have their position/rotation set from a parent body, but thankfully for me it's enough for now.
It seems very strange that the Trimmed Surfaces dialog has no option to select which set of bodies should be acted on, which is a pretty standard feature almost every other dialog of this type.
The next problem you might come across is that a single wing body with no control surfaces will be exported differently to a wing with control surfaces. With control surfaces it becomes a tree structure with origin axes, multiple 'compound' items and a single 'solid' item. Without control surfaces, it becomes a single item of some type I don't even know what the hell it is. The latter cannot be used for further boolean intersections with other shapes. So you might wanna add some dummy control surfaces.
Now I'm stuck on boolean intersections not working if they cross between different sections of the wing... it feels like I'm pushing a huge boulder uphill, every time it seems to start moving it only goes a few millimeters and then I'm stuck again.
So helpful, thank you!!
Thank you for time.
Thank you so much for this video series!
Question: I am working on an idea for a kit plane that I will produce and market the kits for. I have looked at the Sling TSi assembly manuals since that closely resembles what I want to produce, AND they are available for free on their website. I really like the way they presented the work to be done in a graphic sense. You can tell it was probably produced in.... possibly SolidWorks??? I would love to mimic that method, and THIS VIDEO was the first time I saw a possibility of an easy transition from design to "construction documents". In the video you stated that "you can see how this would be useful." Is it useful because now you have a CADD file with the skins drawn? Can you use this in some form to cut the skins into flat sections for cut-out of the aluminum sheet? (I should mention, now that I think about it, my plan is for an all-aluminum project) I guess what I'm getting at is, I would benefit from a discussion of HOW to express your design into construction docs? How do you draw a rib inside of a wing in SolidWorks? What are the CADD options for producing airplane assembly manuals? I am an Architect, so I can draw all day long in DataCad, and by hand on a drafting board, but neither of those methods will do for these types of plans (not if you want to be perceived as legitimate in today's kitplane market). I have used Sketch-up before... It was not comfortable to me. Hard to be accurate. SolidWorks seems very labor-intensive. Can you take this CAD file you just produced and insert it INTO SolidWorks, slice the fuselage in a given area, and use that slice as a saved view by which you now can draw a bulkhead for that station?
Sorry to go on so long. Hopefully you can get a sense of what I'm asking in a general sense.
Thanks again for your videos!
George
I have done a lot of what you've asked about. I've exported wings/tails from OpenVSP and into SolidWorks, Fusion360 and FreeCAD. In CAD the import is either a shell or a solid. I find shells to be a little easier to start with for an aluminum skinned airplane. And YES, I slice the imported file to start making ribs, bulk heads and can use the shell to unfold for aluminum skin cutouts. I'm afraid you have quite a bit to learn regardless of which CAD program you use. I think that once you learn your CAD program you will find it easy to make assembly drawings. Sometime this fall I will probably start on the structural work on the UWS-4 so you will see me doing this kind of work then.
Good luck with your venture. Going into kit production can be Costley if not time consuming. LOL I had planned kit production of an ultra-light loosely based on the j3 Junior size and style. Although mine was a monocoupe all sandwich composite using a combination of foam, carbon fiber, and or S glass or Kevlar. I sold the molds. Because I simply did not have time between ranching and beekeeping. This was nearly 20 years ago. I built my first airplane in the 70s, and several since. All without CAD. Although some were plans built. Some have been of my own design. With that said, if you have the money building with aluminum CAD/ CNC would be the way to go. Real time-saver when it comes to Precision cutting and drilling.
I have a 48"x48" CNC router. At some point I will use it on the UWS-4 build but first I will use tools that viewers are more likely to have just to show that you don't have to have expensive tools to build with aluminum.
2024 ... how is the development of the Kit you had planned ?
@@nevillecreativitymentor Funny I should open this email notification that you posted this response (albeit 2 weeks ago) just as I am getting on my computer tonight to do a little noodling around on my project for the first time in months. I am just finishing up building our new house and getting the old house on the market. That has been my hold-up to getting serious about my new kitplane business. At this moment (well, in about a week, actually), it is full steam ahead. I just started sketching around tonight to get back in the saddle.
I've played around a little bit with OpenVSP, I've built wings and ran some analysis on them, but I haven't figured out how to build a fuslage yet. Have you done a tutorial on that yet, that I just somehow missed?
Hi Reubin, The OpenVSP folks have been working hard on tutorials and doing a great job so I will not be making any more OpenVSP tutorials unless something unique comes up. You can find many great tutorials here: vspu.larc.nasa.gov/ . Chapter one has several good videos on the fuselage. I generally start with ellipse cross sections just to get the cross sections in the right locations and then change them to super ellipses. Super ellipses can handle most of the cross section shapes that I use.
When I import my wing to FreeCAD i am not able to work with the surfaces. I do not have a part tree, its one single body. What am I doing wrong ?
There is just not enough information in your question to be able to help you.
Let me go the other way, how can I import CAD to openvsp
There is a way to do that. There was a OpenVSP workshop lsat year that gave a demonstration on how to do that. Let me look up the URL .... Here it is: ruclips.net/video/PLx4UvH6qdE/видео.html . I hope this helps.
Much appreciated ❤️