SolidWorks & wings

[forgues research]

	Quote: Originally Posted by zx32tt
	Well, the more I jack around with this, the more coninced I am the compufoil, or Profili2 will do the job in 1/10 the time and effort. If I can get my friend "Shreaderman" to do a test, I'll know for sure.

I also use solid works but don't forget, compufoil is a purpose program while solidworks is made for everything and very good at it.

Roger

[Mithrandir]

OK... I used Pro/E (Wildfire III)...
I think the methods I used are fairly simple and similar functionality exists in SW....
I took a lot of screen shots... so I will only provide a little commentary as most CAD Modelers will see what I did....

First thing.. create an Assembly.....

Then Create a "Skelaton" within the assembly. The skelaton is what you use to drive the design intent... example would be the root airfoil and the tip airfoil and the span, maybe the spar cap dimensions... the sweep, dihedral, twist etc etc etc.....By using a skelaton to control all these parameters, all the controlling details are in one location and if the modeling is done with careful attention to references and making the geometry robust, fairly substantial changes can be made to the skelaton and the updated geometry shouldn't crash.....
In slide #1, the assembly only consists of the skel and the skel only has a coord-sys and default planes.....



the next two slides, we are working in part mode... with the skel active, we create the airfoil sections... these could be made from data/X-Y-Z Cords or imported data...then appropriately scaled...




next we connect the root section to the tip section with straight lines...



note the trailing edge is not to a sharp edge....shallow sharp edges can sometimes cause probs down the line and aren't real anyway...





Now we create the OML of the wing... (Outer Mold Line)... this is the final shape we want the sheeted wing to have...

Note the OML trailing edge has a finite thickness

[Mithrandir]

Now that we have the OML, we need to accomodate the Sheeting thickness as we want the ribs to be undersized the thickness of the sheeting...
Pro/E has a simple functionality to simply offset the OML surface inward say..... 3/32 of an inch... inreality, you might go a little further to accomodate glue line...
I changed the OML to yellow and the Inner Surface to Gray... the gray now represents what the underside of the sheeting is...or the edges of the ribs....











Now I "Hide" the gray "IML" and define the spar geometry.... I simply used a few datum curves and surfaces with boundaries...








Next I need to trim the Spar surfaces with the IML of the wing... In Pro/E this is called "MERGE"

[Mithrandir]

here you can see both spar surfaces merged with the IML... first one close up... 2nd one overall...





Now lets Unhide the OML so you can see it all together... remember.. all this geometry resides in one model.. the skelaton!!! The yellow is the OML... the gray is the IML, the surface to define the ribs....








Now... in the Skel, I am going to control the rib spacing... and I choose say... 4 inch spacing... I define the first rib location (BL-4) to be a plane offset from the BL-0 Plane.....



Next.. I "Pattern" the plane to get a whole series of planes all spaced 4 inches apart..



The next image is the intersection of the BL-4 plane and the IML surface... I turned the planes of to reduce clutter....



The next slide shows what it looks like when I also "Pattern" the curve generated from the Plane-Surface intersection.... since the planes were all patterned.. Pro/E "Knows" I will want to pattern the curve



and here are all the intersection curves....

[Mithrandir]

Now I will hide the IML surface so we can see all the Rib Curves.....






Now.. in Assembly Mode, I create the First rib PART... here you can see that I reference the Rib Curves from the Skelaton to define the rib edges... I also chose to extrude equally in and out from the plane... so the rib is centered on the plane that defines its location....



And here is an image of the wing with a couple ribs... the ribs are each seperate parts... and as long as I keep the references straight... and the geometry doesn't overlap or fail... any changes I make to the skelaton will cascade down to each rib!



and in this image, you can see that I fattened the sections up and increased the taper ratio in the skelaton and the changes did indeed cascade down to the parts...



now it is just a matter of creating each rib as a seperate part...repeating the above process in assembly mode.

[Spooky]

Nice work Mithrandir,

Here's a quick and dirty way to make some ribs in SW... by that I mean I did this in less than an hour with pics; no dimensions, and very basic shaped sketch's, just as an example. You can detail out the sketch's for better overall design and fit (notch's, cutout's, etc.)

Step 1) I made a very basic airfoil sketch on the RIGHT Plane, and another sketch on the same plane with lightening holes as a template for later on.

Step 2-3-4) Added a Plane at a distance (length of wing) off the Right Plane; insert sketch and converted entities from Sketch 1 (airfoil sketch), and scaled it down, I used 75% for this example.

Step 5-6) Inserted a sketch on the Top Plane and connected the 2 Airfoil sketch's with lines (guide path for lofting). Make sure to use the Peirce relation where they intersect.

Step 7) Loft the 2 airfoil sketch's, using the outline sketch as the guide curve.

Step 8) Here's were you make your Plane's to use to cut up the model (wing). Used "Plane at a distance" with multiple copies (rib spacing) for these, making sure to make "rib thickness " Plane's at each end.

Step 9-10-11) Now comes the slice and dice... You split the solid body (wing) with all the Plane's and pick the parts you want to keep and you have basic ribs.

Step 12-13) Here's where those earlier hole sketch's come into play; Roll back the feature manager tree to before the "Split Body" so you have just the wing, not ribs. Insert new sketch's and use convert entities for each hole on the 2 end faces or you can make new sketch's. Loft-cut these sketch's to get the lightening holes, or whatever shape you want.

Step 14-15) Roll forward the feature manager tree and you have ribs, (15) now just pick each rib and save it as a separate part which can be assembled later. You can "Mirror" all the ribs to get the other wing if you want.

Like I said, just a very basic layout to use as an example.... and just one of the way's to do it.

[Mithrandir]

I really use often the "Insert" mode capability of Pro/E (and SW)...

[tommy321]

	Quote: Originally Posted by Spooky
	Nice work Mithrandir, Here's a quick and dirty way to make some ribs in SW... by that I mean I did this in less than an hour with pics; no dimensions, and very basic shaped sketch's, just as an example. You can detail out the sketch's for better overall design and fit (notch's, cutout's, etc.)

Quick question on using this method.

Once you've made your rib part files by cutting up this lofted solid. Do you disassociate them somehow from this loft?

I'm thinking about when you take the rib part over to the "real wing" assembly and then want to make cuts, or adjustments based on what you find in the real wing assembly (i.e. servo mounting holes, pushrod/wire routing holes, etc).

Once the wing ribs are in the final assembly, do they still inherit properties from their original loft? From the wing assembly? From both?

Thanks to both of you for the great write-ups .

Tom

[Spooky]

No need to break the Parent/Child relation, you can go back and edit the original loft sketches to update the ribs by adding more/less holes or cutouts, or cut-up each rib separately or together in the wing assembly to get what you want. The lofted wing/ribs stays a separate part, yet still retains relations with each rib... cutting up the "child part"(rib) doesn't affect the "parent" (lofted wing). If you look closely at the last pic, your actually saving each rib as a separate solid body to it's own part file.

If you need anything, let me know, I'd be happy to help.

[Mithrandir]

The trick is to work in assembly mode... and keep as much "Intelligence" as possible in the skelaton

[Spooky]

	Quote: Originally Posted by Mithrandir
	The trick is to work in assembly mode... and keep as much "Intelligence" as possible in the skelaton

With this "Quick & Dirty"method, you still get the "Intelligence" when assembling the ribs without having separate sketches for each rib, and the added bonus of being able to change them (ribs) from within a single part file (lofted-wing), instead of individually, to make changes in the final assembly.

[zx32tt]

Spooky & Mithrandir, could you post your solid models here so others could use them? I can read SW 2007. Maybe you could also do iges and step files.
zx32tt

[Spooky]

I could make up another "Wing-Loft" part file to post if you want, I didn't keep the original, it was made just as an example, then deleted.

[Mithrandir]

	Quote: Originally Posted by zx32tt
	Spooky & Mithrandir, could you post your solid models here so others could use them? I can read SW 2007. Maybe you could also do iges and step files. zx32tt

Can we attach zip files to posts?
Can you read step files? or is iges best?

[zx32tt]

I dunno which will be the best for most users. Do both, and we can see what works. I found some pretty good sw models of servos that I could post as well.
zx32tt