Basic overview, solid model design

[wcfn100]

They're likely being used by the CAD program behind the curtain, without you having to explicitly manipulate them.

I was able to look it up.  NURBS is totally separate from solids modeling.

NURBS creates just a surface with no thickness, while solids modelers give their object thickness and mass.  They are also created parametrically while NURBS uses direct modeling.

I think I get your point though that the math to create the complex curvatures is probably related, but NURBS in itself is a specific way to make model, not just the curves.

As an example, programs like Maya and Rhino are NURBS modelers as opposed to Solidwork, Inventor or Fusion360 which are solids modelers.

Jason

[bbussey]

You can however create a solid body in SolidWorks by extruding up to a surface body, and you can import surface bodies created in other programs.

I use surfaces to create stamped gondola ends.  I create the relief as one surface, then I duplicate the surface and move it back the distance that I want the thickness of the end to be, and then loft between the two surfaces to create the solid end with the stamped pattern on the front and the back.
 

[Chris333]

Gonna have to search loft and Sketchup and see if it does it. Would make the ends of a passenger car roof easier. And where a smoke stack meets the smoke box.

[Lemosteam]

You can however create a solid body in SolidWorks by extruding up to a surface body, and you can import surface bodies created in other programs.

I use surfaces to create stamped gondola ends.  I create the relief as one surface, then I duplicate the surface and move it back the distance that I want the thickness of the end to be, and then loft between the two surfaces to create the solid end with the stamped pattern on the front and the back.
 

Bryan, check to see if Solidworks has the capability to extrude a complex surface or dimensionally thicken one to either or both sides of the surface.

[Lemosteam]

Gonna have to search loft and Sketchup and see if it does it. Would make the ends of a passenger car roof easier. And where a smoke stack meets the smoke box.

There is really no need for that if the cad tool has variable filleting.

Create 1/4 of the roof with a end view curvature. place it in the side view and create an arc at the center plane.  Create another arc in the plan view that represents tie plan view curvature at the end of the car.  Revolve the side view cure about the vertical axis of the plan view cure center to cut away the end if the first extrusion.  What is left behind will have sharp edges where the cut was made.  Fillet those edges with a 3-6mm fillet starting the the rooftop endpoint, and reduce the fillet to 0.2mm at the bottom. My tool has a shell capability where I can choose the surfaces I do not want the the tool will thick to an offset of all the surfaces left behind to create a hollow roof then I can join that to a car body or like I do with my snap in roofs, add the locating and snap features and then reflect the body twice as mentioned up thread.  Clerestory is much more complex but done similarly.

[JeffB]

This is one of the reasons I always suggest SolidWorks.  It is difficult to use a solid to create complex curved surfaces and have them look smooth in some highly complex surfaces.  Higher end CAD tools have a huge range of surface development tools to manage compound curvatures such as the prow of the 3768, etc.:

As a fairly proficient and regular SolidWorks user, I concur...  But the problem is that SolidWorks is unavailable to most, as it is a very expensive software package.  I have it through work on my work laptop, which I frequently bring home to do hobby design work. 

I see guys struggle to do things using the free 3D, or other low cost 3D modeling modeling software, that are fairly basic solid modeling that you can do quickly and easily in SW.  But that's why it's so expensive, it's a very powerful software package.

JB

[bbussey]

There is really no need for that if the cad tool has variable filleting.

Create 1/4 of the roof with a end view curvature. place it in the side view and create an arc at the center plane.  Create another arc in the plan view that represents tie plan view curvature at the end of the car.  Revolve the side view cure about the vertical axis of the plan view cure center to cut away the end if the first extrusion.  What is left behind will have sharp edges where the cut was made.  Fillet those edges with a 3-6mm fillet starting the the rooftop endpoint, and reduce the fillet to 0.2mm at the bottom. My tool has a shell capability where I can choose the surfaces I do not want the the tool will thick to an offset of all the surfaces left behind to create a hollow roof then I can join that to a car body or like I do with my snap in roofs, add the locating and snap features and then reflect the body twice as mentioned up thread.  Clerestory is much more complex but done similarly.

I loft with multiple sketches to create roof end contours, it is more precise. Especially with the contours of New Haven streamlined equipment.

[Sumner]

As a fairly proficient and regular SolidWorks user, I concur...  But the problem is that SolidWorks is unavailable to most, as it is a very expensive software package.  I have it through work on my work laptop, which I frequently bring home to do hobby design work. 

I see guys struggle to do things using the free 3D, or other low cost 3D modeling modeling software, that are fairly basic solid modeling that you can do quickly and easily in SW.  But that's why it's so expensive, it's a very powerful software package.

JB

Exactly why I recommend Fusion 360 to anyone who is a home hobbyist.  It has CAD powers similar to Solidworks and they can use it at no expense if they are only using it for their hobby or other non-commercial uses.  If they move in that direction then they pay for it but then hopefully they have income. 

More here................

( https://www.autodesk.com/products/fusion-360/personal#:~:text=Fusion%20360%20for%20personal%20use%20is%20free%20for%203%2Dyears,%2C%20manufacturing%2C%20and%20fabrication%20projects. )

...... about the differences between the 'personal use' and the 'paid version.  The paid one lets you do things like perform milling operations on a CNC mill and other options that I don't think most of us are going to need.  As far as the design work and what you would need to use for 3D printing I believe it is all there.  I see the ability using it to do most of the things that have been mentioned in this thread. 

You can often get to the same end point using different tools but some allow you to do it quicker and easier.  That is what I've found with Fusion vs when I used SketchUp but I never did much solid modeling with it.

Sumner

[wcfn100]

I use surfaces to create stamped gondola ends.  I create the relief as one surface, then I duplicate the surface and move it back the distance that I want the thickness of the end to be, and then loft between the two surfaces to create the solid end with the stamped pattern on the front and the back.
 

I'll have to look at that type of design.  I stayed away from surfaces in the past because I don't think you could get a water tight model from them in the early days of 3D printing when you could only print a few types of files.

Jason

[bbussey]

With the gondola surfaces, I delete them after the solid loft is created. Also, I create the first surface by creating a solid master first, creating an offset surface at zero offset and deleting the solid master.

[Chris333]

I just installed an extension into Sketchup to let me loft. Had to sign in at the extension site which meant I had to have them e-mail me my username , verification code, and password. Then to install the extension into Sketchup I had to sign in to that which meant I had to have them e-mail me my username , verification code, and password.

Yeah this is ghetto.

[Ed Kapuscinski]

I just installed an extension into Sketchup to let me loft. Had to sign in at the extension site which meant I had to have them e-mail me my username , verification code, and password. Then to install the extension into Sketchup I had to sign in to that which meant I had to have them e-mail me my username , verification code, and password.

Yeah this is ghetto.

What did you expect to do in exchange for hundreds of hours of someone's work?

[Chris333]

What did you expect to do in exchange for hundreds of hours of someone's work?

I don't understand how signing in did anything. It was a free program that I installed a free plug in. I get no junk mail from them so they must not be marketing anything to me. Just a pain to sign in to something once every 4-5 years. Like an e-commerce site that makes me create an account.

And the hours of work was probably something like my 3D models. I took hours to make them for me and since they are just laying around on my computer I put them up on Thingieverse for free.


Or why when I'm signed in to Thingierverse do I still need to prove I'm not a robot to post.

[Ed Kapuscinski]

I don't understand how signing in did anything. It was a free program that I installed a free plug in. I get no junk mail from them so they must not be marketing anything to me. Just a pain to sign in to something once every 4-5 years. Like an e-commerce site that makes me create an account.

It provides a level of access control to their work product. So, for example, if they have to stop offering the thing they can by simply disabling access. It gives them control over the thing they created.

And the hours of work was probably something like my 3D models. I took hours to make them for me and since they are just laying around on my computer I put them up on Thingieverse for free.

Some do it for love, some do it for money

Or why when I'm signed in to Thingierverse do I still need to prove I'm not a robot to post.

The internet is still the wild west of bad actors. Bots, bots and more bots. For something like Thingiverse, the CAPTCHA is an easy to implement way to help weed out some of it.