flugzoid

Any of the CAD gurus have any thoughts on the which software would be more capable for a non-cad user to learn and be happy with? Rhino is quite a bit cheaper, however not sure if it's a classic case of "get what you pay for." I've heard very good things both about Rhino 3D and Solidworks. Appears Rhino runs around 1000 (Plus add ons?), and Solidworks runs about 4K (Plus another 20% or more for add on's, 15% more for training, etc.)...would be into Solidworks about 6500 to get all trained up. Any thoughts would be appreciated.

Flugzoid.

ptxman

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I use Rhino (v2 still) & it was my introduction to 3d cad having used autocad 2d quite extensively. Its a great program. Do a search here & you will see some pretty neat examples. You can do pretty incredible things after a short while, but like anything, its time & effort ramping up the learning curve. A lot of the command usage was autocad in nature (or easier) so it made the transition easier. I heard that Rhino started out life as a 3d add-on to autocad because acad was so pathetic & limited at the time. If you have zero cad experience, you will have a bit more work in front of you. The best thing from both a financial & learning standpoint is to take some courses & see how you like it at a much entry cost.

The specific model project I worked on was eventually exported & became high end cnc milled molds. Rhino is known for good import/export file capability in that regard. It is also very well supported on an active (free) newsgroup basis. Sorry I dont know much about solidworks to compare but Im a very happy Rhino customer. Their v3 has been out for quite some time, some of the new features seemed a bit buggy from the n/g discussions but I suspect they have things well under control. . Good luck.

flugzoid

Thanks ptxman. I keep finding myself going back to the Rhino software with all the positive comments. One of the short comings that I've found, however, is that when I go to the bookstore to look for books on Rhino (specifically) or any other CAD programs, they seem to be absent....unlike the myriad of other books that you can find on Adobe Products, MS products, etc. I wish that there were some books that I could find to start running through basics. It'd be even better if there was something that came along with the Software...at least to preview lessons and stuff. Any ideas?

Thanks again ptxman.
Flugzoid

ptxman

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Generally speaking, aftermarket books are much tougher to find for 3d cad. I think its because the end users of this software is more high-end industry vs home users. Same goes for products like Mastercam & Solidworks. Rhino's book that comes with the software is pretty good by most standards. They also offered 2 training guides. Thats what I used. They start at a very basic level & progress from there. Check Rhino's website under training or resources etc, but I think theses guides are actually included as .pdf files on the software cd, the paper copy is for convenience & what 3rd party education firms have been using as training guides. Im sure Mcneel would be happy to answer your questions regarding this.

I bought my Rhino from these guys, only because they are the Cdn Rhino rep, but they show the same books as their course material. http://www.schindler.ca/products.htm

flugzoid

Good link. Thanks ptxman. Got another question. Maybe this is too much of a can of worms though. Is there a significant difference between "solids modeling" and "mesh modeling?" I might be way off the mark here on my observations. Seems that all the Rhino stuff is created with a sort of "mesh", where as other CAD (like Solidworks) I'm not seeing any meshes. Not sure if it's a fundamental difference with respect to limitations, or if it's just a different way to skin a cat. I guess when I see a "mesh" I get concerned with what I would be trying to do. For example, if I had a "solid", then I picture myself being able to slice and dice the entire computer generated product, thus being able to make an infinite number (almost) of cross sections. I could cut out big chunks, hollow it out, and have a perfectly fitting piece should I try and make a mold or templates. The mesh models appear that the stations/formers themselves are created, then everything is surfaced around them. I'm not sure if I'm making sense with any of this. I guess the bottom line is that I'd like to be able to have a computer generated structure to generate many templates for referencing in carving out my foam fuselages. I'd like to be able to make modifications to CAD model, and place all kinds of inner workings inside them to make sure that all the servos would fit. Mike James, another one of the CAD Gods, works with Carrera I believe, and he has everything designed and fitting before exploding the design and making the prototypes. Here again, I'm not sure which method he's using. Sorry for my rambling.

Flugzoid

ptxman

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> Is there a significant difference between "solids modeling" and "mesh modeling?"

You should really get on the rhino newsgroup & pose those questions for qualified answers. Those guys are pros & do this stuff for a living. Im not an expert by any means but here goes...

A solid modeler is preferrable over a mesh modeler for the reasons youve outlined & particularly when it comes to making the part on a cnc mill. I believe Rhino meets what you call a solid modeler. It has a host of solid primitives from which you can build up, integrate & subtract 3d pieces to make composite solids in a building block manner. But thats really a small part of its capability & it doesnt get you far in the real world of curvy fuselages with complex varying fillets or swoopy car fenders. Its claim to fame is its ability & tools available to create highly complex flowing or deformed surfaces and do this with a high degree of precision. Thats what the nurbs based (internal mathematical representation of surfaces) is all about. Anyway, this allows you to treat them essentially as solids, calculate mass, volume, moment of inertia, rendering - all that good stuff.

> Seems that all the Rhino stuff is created with a sort of "mesh", where as other CAD (like Solidworks) I'm not seeing any meshes.

You have to be careful about what you see & what is happening behind the scenes. It takes computer horsepower to generate fancy color renderings with material assignments etc. There are times when that is appropriate (the finished product). But when you are designing, simple shaded views are fine because they regenerate so much faster. Other times you are concerned more with isoparms (like contour lines of the surface) & you may wish to have these displayed. But they are all different views of the exact same surface as far as the program is concerned. That in itself does not make it a solid. Meshes usually stand out as being coarser but thats because they are internally represented more like facets than continous surfaces. Better stop before an expert puts me in my place!

> I picture myself being able to slice and dice... number of cross sections.... cut out chunks...hollow it out... perfectly fitting mold or templates

I know exactly what you mean & have done all the above & more. Recignize Im self taught so these are kinda simple, but heres some examples

ptxman

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showing edges & some isoparms, this is the predominant working view when designing

ptxman

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This is a very basic 'shade' of the surface. It is turned on just to validate the 3d aspect & the is generated on the screen almost instantly.

ptxman

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This example shows the end result where where specific material types, texture & color are assigned to different parts of the surface. I think I picked shiny plastic, but could have picked chrome or cork for that matter. As well, lights are set in place at specific points, intensities & angles. A base surface is added as a visual datum and (what still continues to blow my mind) the program magically figures out the reflections & lighting effects all by itself.

This example was used to hilight a particular tip shape option. But remember that this is all the exact same surface to the cad program whether shown as wireframe, quick-shaded or fully rendered. BTW, the rendering is a seperate plug-in package called Flamingo which works inside Rhino.

This same Rhino 3d file was exported as-is & eventually used to make cnc milled metal molds at very fine tolerance. But...thats a whole nuther story, yet another specialized software package to generate toolpath, lots of engineering know-how to superimpose the surface on the blank, high end precision milling machine, expert machining knowledge, big chunks of expensive materials ...Ka-Ching $$$$$

ptxman

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This shows another shading option - zebra striping - useful for visually hi-lighting how well surface contours flow & match other surfaces.

ptxman

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These solids were made by a combination of cad techniques - extruding planar curves, solid primitives, slicing & dicing along various section lines. (Its showing a view of a female mold section & the extensing jog seam of the layup component).

flugzoid

Thank you ptxman for the demonstration. They look exactly like solids. Looks like I have to get some research under my belt on this stuff. You've been a big help. Thank you.

flugzoid

nIgHthAwK17

I can vouch a big positive for Rhino. In my opinion, it is by far the most user friendly 3D CAD software around. Not only that, it *likes* organic shapes - airplane fuselages, airfoils - things of that nature.
To answer your question about Rhino "solids" - Rhino considers any set of enclosed and joined surfaces as a solid. Two things prove this - 1. It will allow you to use the Boolean tools under "solid tools" if and only if the solids are enclosed and joined; and 2. When the surfaces are as stated to create a "solid", it will give you volumetric measurements, mass centroids, etc. as it would only if one could be considered a solid as opposed to a few surfaces. Hope this helps.. --

PS - Before I forget - don't get V3 of Rhino if you can - its got BUGS, not viruses mind you, just some quirks they haven't figured out yet... V2 is the one to get if you can.

flugzoid

Thanks for the information nIgHthAwK17. Will be taking a very close look at the Rhino package. How do you recommend getting an older version of the software? Do you think that distributor would sell them? Will keep reviewing the Rhino website.

Thanks
flugzoid.

MarkVZ

I use a composite of AutoCad and Rhino. I like AutoCad because of it's ability to import raster images such as technical drawings or 3-views. For scale models, I can use AutoCad to trace complex distinguishing curves from doccumentation.

When I need to make complex curved shapes, that's where Rhino comes in. I can take the bulkheads or whatever that I made in AutoCad, import them into Rhino, and loft or sweep whatever I need.

Then there's Unigraphics... it's very capable in the right hands, but for me it's somewhat awkward to use. I'm learning.

ptxman

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You can do this same thing in Rhino, plus it has a few more alignment correction & scaling tools which are handy. It will import all sorts of graphic formats as I recall, jpegs, gif, tif etc - Im assuming thats what you mean by raster image, scanned or otherwise?

nIgHthAwK17

ptxman,
You are absolutely right about Rhino being able to take on any sort of common graphic file to use as a basis for your drawings. I have already used it in order to help a friend of mine scale a P-40 to his liking... worked out rather well...

--CG

MarkVZ

ptxman, tell me more

What is the procedure for importing a raster image into Rhino?

Thanks.

MarkVZ

I just used a bitmap background to try to trace in rhino, but it pales in comparison to the representation that AutoCad gives the raster images. In rhino the image is very choppy. I'm working with Piper technical drawings, not simple 3-views.

Is there any other way besides background bitmaps in rhino?