SolidWorks & wings

[Spooky]

	Quote: Originally Posted by Thomas_W
	I just tried this, and amazingly my simplest mind figured most of it out. now could you explain how you go about making the cuts in the wing ribs on the underside of the "loft" / wing skin. I tried to use an extrusion cut, but it went from the center line of the end planes.

Wasn't thinking when I answered your question, so I edited the above post to make it clearer, swept-cut should have been loft-cut, my bad . And when I looked back at how I did it, I used one sketch and swept-cut that using the wing-loft guide curve for the LE & TE swept-cut guide curve too.

Dean

[t.muehlnickel]

has anybody experience to design a complex fuselage(cross sections not rectangular) with solidworks? My way is too heavy; it generates a very complex model and then it´s not easy to work with.

Kind regards Torsten

[Spooky]

	Quote: Originally Posted by t.muehlnickel
	has anybody experience to design a complex fuselage(cross sections not rectangular) with solidworks? My way is too heavy; it generates a very complex model and then it´s not easy to work with. Kind regards Torsten

Not sure what you mean by heavy and complex, do you have any example's to show? I've designed a couple planes in SW, and everyone has their preference on how they design stuff. I think it comes down to how familiar with you are with the software and how you are going about making your parts, there is no easy button, it does take a good amount of effort and planning.

Here's my latest design, which has already been sent out for laser cutting.

Dean

[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/