SolidWorks & wings

[t.muehlnickel]

Hello Dean,
I work with surface model first and create the sections and fuselage skin. Then I give them thickness and volume. Now build up the former and inner structure. I work with the fuse in a multi body part, I think it´s easier? (The wings etc. are a assemblies) To constrain these parts in a big assembly take a lot time and generate mistakes.
How you are working, without surface model? Do you use parts and assemblies? How you are generating the stringer?

Torsten

[Spooky]

Hi Torsten,
I use Solid models for everything, then split up the model into the parts I want. I'll use a 3-view plan and make sketches of the fuse sections, then place those sketches on the corresponding section plane and loft them into a solid, very similar to the wing lofting a few pages back. Then "shell" out the solid fuse to the former thickness I want and split the resulting body in half. After that, I'll use half of the fuse body to split into formers, and the other half for making stringer notches, then mirror the notches onto the former half. The reason I use half and half is that to get the guide curve for the stringer notches, I use the full half body and a plane and use "Sketch tools, intersect curve" and use that for the guide curve, one whole spline the length of the fuse, not just pieces, then swept-cut the notch. It sounds more complicated than it is, here's a few pics to help you get the idea.

Dean

[Mithrandir]

The Top-Down philosophy suggests a "Master Surface"..... typically as a Skelaton in Pro/E-Speak.... then copy the master surface regions as needed for each part of the model.... in ASSEMBLY Mode. Try to keep the overall intent in the skelaton..... and geometry that drives or affects multiple parts of the assy..... the skelaton serves as a one stop shopping for the driving geometry....

Starting out with surfaces (If SW has that capability) is the hot ticket.

[Spooky]

	Quote: Originally Posted by Mithrandir
	Starting out with surfaces (If SW has that capability) is the hot ticket.

It's a matter of preference, it's much easier for me to use solids and work from that, no stitching surfaces together, besides, you have to create geometry to get you surfaces anyway, where as you can pull your surfaces from the solid or slice it up into parts, whatever you want, and it still keeps the Parent-Child relations. I do save off each individual sliced solid part to it's own part file, then make my assembly, adding each part, which also, because you already cut the master parts in-place, imports into the assembly in the correct position without having to mate them together, simple and easy, and changing the master file parts, changes the assembly accordingly. Starting with just surfaces adds extra work, IMO, that's not necessary for making the end product, cut files. Like I said, it's a matter of preference and what your comfortable doing. I personally like to make it quick and simple, with less of a chance for things to go wrong down the line.

My long winded 2 cents,
Dean

[Mithrandir]

	Quote: Originally Posted by Spooky
	It's a matter of preference, it's much easier for me to use solids and work from that, no stitching surfaces together, besides, you have to create geometry to get you surfaces anyway, where as you can pull your surfaces from the solid or slice it up into parts, whatever you want, and it still keeps the Parent-Child relations. I do save off each individual sliced solid part to it's own part file, then make my assembly, adding each part, which also, because you already cut the master parts in-place, imports into the assembly in the correct position without having to mate them together, simple and easy, and changing the master file parts, changes the assembly accordingly. Starting with just surfaces adds extra work, IMO, that's not necessary for making the end product, cut files. Like I said, it's a matter of preference and what your comfortable doing. I personally like to make it quick and simple, with less of a chance for things to go wrong down the line. My long winded 2 cents, Dean

I know absalutely nothing about SW or what is easy and what is hard.... so I really can't comment one way or the other about how you are doing this.... I have heard it is like Pro/E "Lite" with a better interface... but not as mature and not all the capability of Pro/E.

"MY" experiance has been Aircraft design, particularly (well... nearly exclusively) the Predator UAV Series of planes.
These are all molded composite planes, that are essentially built "From the Outside, In"

With Pro/E, surfacing is not harder then creating solids. Surfacing includes all the methods and tools of solids plus some additional capabilities.
And in the Top-Down design methodology, having your skelaton as a solid is not as elegant.

This is simply a commentary on what my experiance has been with Pro/E and how I have modeled airplanes in the past..... not intended to evaluate how you use SW.

[Spooky]

	Quote: Originally Posted by Mithrandir
	"MY" experiance has been Aircraft design, particularly (well... nearly exclusively) the Predator UAV Series of planes. These are all molded composite planes, that are essentially built "From the Outside, In"

Yes, SW too has more options for surfacing than I care to use, but your talking real world engineering applications, where I'm talking about making model planes, different strategy, much less restrictions on design and application. Sure, some things translate, and there are certain rules to follow (never was much for rules) but if I can get the results needed by cheating a little, I'll do it. Where as in designing a predator, you need all the rules and discipline.
I actually started out with Unighraphics, designing automotive parts, airfoil & core molds, and other assorted stuff. For me, SW was learned as a second language, so to speak, but I've used it alot more over the years because of it's popularity.
I still think It still comes down to preference and familiarity, whether you use surfaces or solid models, each has their good and bad points, it's what works for you that counts.

Dean

[t.muehlnickel]

	Quote: Originally Posted by Spooky
	Hi Torsten, I use Solid models for everything, then split up the model into the parts I want. I'll use a 3-view plan and make sketches of the fuse sections, then place those sketches on the corresponding section plane and loft them into a solid, very similar to the wing lofting a few pages back. Then "shell" out the solid fuse to the former thickness I want and split the resulting body in half. After that, I'll use half of the fuse body to split into formers, and the other half for making stringer notches, then mirror the notches onto the former half. The reason I use half and half is that to get the guide curve for the stringer notches, I use the full half body and a plane and use "Sketch tools, intersect curve" and use that for the guide curve, one whole spline the length of the fuse, not just pieces, then swept-cut the notch. It sounds more complicated than it is, here's a few pics to help you get the idea. Dean

Hello Dean,

your method is very simple and good. I have to think about it on my bipe project .....

- in my design I have area with and without sheeting ...
- wing to fuse and stab to fuse intersections
- inner fuse design with side walls, upper floor etc. to support gear and engine box

I think I have to use your "master part method" several times and/or split it in much more sections - don´t know yet ....

I want the similar structure design like the EF Yak or Weihershäuser Ultimate, both are very rigid and light airframes.

Best regards,
Torsten

[Spooky]

Hello Torsten,
The method I used for making the formers and such, was geared towards the type of build (stick & tissue), not really the same as what your doing, but can be adapted, like slicing sections thru the fuse model where you want crutches or internals, and then modding those parts to your liking (lightening holes, etc.) same principle, cut one half and mirror. And for sheeting, for a visual and workable part, I'll copy a surface off of the model, yes I do use surfaces too, trim it to shape, thicken it, and use that to subtract from the parts needing sheeted. But to save time, I'll just offset the surface off the model where needed, trim, and subtract it from the parts, basically the same thing. Either way you get your relief for the sheeting on your parts.
For the wing, stab, fuse intersects, I like to use slotted crutches that basically locate and lock in place to glue or screw.

Good luck with your design,
Dean

[Mithrandir]

IMHO, if you are going to model a plane, and then make a zillion wood parts from it.... use the top down design philosophy. Model the OML's in a Skelaton,(Wings L & R, Stab, Fuselage, canopy, cowl, vertical, LG, wheel pants etc). Then copy regions from the skelaton, (in assembly mode),like a wing skin, or a turtle deck, or a vertical... what ever, directly into each part....

This is a robust way to have a model with no circular references and will update/regenerate properly without the references getting out of control.....

I would be very s'prised if SW didn't have all this capability.....
With a high fidelity model, and prolly 25 to 35 parts in the fuselage alone, tidy and good practices will pay off, and will help you to become a better modeler.

this has been a pretty good resource for Pro/E... I 'xpect they have good SW stuff too.....

http://www.mcadcentral.com/

[Volstruis]

Gidday
This is a tedious process, but I have done it for a 29% Extra. You need the root rib profile and the tip rib profile. Once you have these drawn in AutoCAD ( thats what I used) You need to recreate the profile using the arc / line/ fillet etc commands and match as best as you can over the profile, with minimal amount of lines. Separate them, then convert to polyline. Delete everything else from the drawing and purge.
Insert .dwg or .dxf into SW, on chosen plane. Create another Acad drawing for the tip rib. Follow same procedure.
Insert into SW in new plane spaced as required to suit wingspan.
When lofting select same position on root as tip otherwise it will twist.
Section at spacing required. make drawing in SW , print. OR copy and paste drawing into Acad.
Make separate drawing for each rib from section, then make separate parts for each rib in SW. Insert into SW assembly, and you have a skeleton.
I only used it up to the drawing part as I did not need a SW model. Just wanted the ribs.
Hope this helps
Don

[zx32tt]

This is why I plan to use Compufoil to generate rib forms. Its just too complex to do this in SW everytime I need to loft ribs.
zx32tt

[Vern Smith]

I have some questions for those of you with SW knowledge. I have some familiarity with the lofting function and see that it works very well with what I would describe as simple curves and predictable angles, like airfoils and fuselage cross sections. I would like to know how you would create either a solid or surface skin for compound curves. Examples would be a bird egg, a wing tip, a under wing electronics pod or drop tank, a submarine torpedo. etc.

Assuming you created the body of the cylindrical shape with a series of "formers" on planes and lofted in succession, what do you do when it comes time to close the ends with a dice ball like surface that blends seamlessly into your previously created tube? I read through this entire thread so I apologize if I missed this part


Thanks for the help,

Vern

[King Snake]

You can give it a guiding curve to use when it makes the loft. You just define the profile and then select it when you make the loft.

Don,
I am new to the forum so I don't know what has been discussed. If you have the .dat airfoil file it only takes like four steps to get a lofted wing from it. Most manufacturers use known airfoils so you just have to find the one they used. If not then you just make your own point file from xfoil or autocad. Then...

Format the file (add a third column "Z", remove the headers, and save as approperate type)
Import the airfoil using curve from XYZ, and scale it to the appropriate size
Close the profile (line at trailing edge)
Select the profiles and loft. (select guiding curves if needed)

If it twists you only need to change/add lofting points.

Vern,
There are three basic ways to do complex curve lofts in SW. The first is to use a guiding curve like described above. The second is to create multiple profiles and then loft between them. Basically slicing the egg and then recreating it. Another way would be to create a profile and then revolve it around a central axis (great for eggs, not for wing tips).

You could also loft using a central curve (creating snakes).


Hope all this helps!
-NK

[300S ENIGMA]

So what year is your 300Z there "zx32tt"...?...hehe

Have a Stillen Stage 6 modded one....mine is a 91 with a boatload of mods

[zx32tt]

its a '91 in stage 3 tune. I'm the 2nd owner. It's got 62k original miles on it.. You are the only one to ever make the "Z" connection.
zx32tt