What About 3D CAD?

The first rule for printing in 3D is the presence of a 3D file.

The next article will lead you through basic computer-aided design (CAD) terms, will review the market players and will guide you to the best options to start design for free with a robust 3D CAD.

There is one common principle today for all 3D production machines, from a $150 self-assembled home printer to a million-dollar machine that prints medical and aerospace titanium parts, all of which receive the printing instructions from a program that prepares a 3D STL file. Software then slices the STL file into layers and converts the two-dimensional mask created in each layer into instructions for the 3D printer. For a successful print, the printer software must have a 3D file that accurately describes the body and its details. Currently, all software that sends instructions to the printing machine can work with at least one standard file called STL that contains a collection of 3D polygons which describe the 3D objects. There are dozens of kinds of software for creating 3D objects using SOLID, surfaces or Mesh technology and each one of them can export STL files.

The 3D software can be divided into three groups. At the top we will find the expensive High-End software. In the middle are the mainstream software that are common in design offices and universities, and there is also the group of software for amateurs and makers, which of course is the cheapest. In the following list I will briefly review some of the popular modeling software for “small” objects (as opposed to civil engineering and architecture programs), with an emphasis on the most suitable for beginners.

Before we proceed, we will become acquainted briefly with a number of technical terms that are important for the continuation:

Basic terms:

Solid – The term solid is not just the name for some popular software. Solid technology allows you to design precise and detailed 3D bodies while providing physical properties to the computerized model that bring it very close to reality. “Solid parametric” indicates that the software allows changing the 3D model by changing predefined parameters such as dimensions. The solid parametric software is the master in the world of mechanical engineering.

Mesh – A three-dimensional model consisting of a network or a collection of lines forming three-dimensional polygons that represent the 3D model. The Mesh model is less accurate, cannot be modified by parameters and is more suitable for creating complex organic shapes and free-form design bodies. Common mesh file extensions are STL or OBJ and sometimes VRML.

Direct Editing – A term associated with solid software which describes the ability to easily modify and reconstruct 3D objects without relying on the original parameters. Direct editing is considered a technique that is more suitable for beginners and casual users.

Parametric – A 3D parametric model is controlled by dimensions or constraints in a way that changing a value will change the model geometry. Parametric models can capture the design intents, control the relationships between features and parts in assembly, create associative drawings and maintain a virtual prototype.

Surface – While solid describes the entire body, surface software only deals with external topology. The “surface” capabilities enable the creation of more complex geometries while maintaining a smooth, flowing appearance. The automotive industry uses surface software to shape the curved surfaces in the vehicle. Surface technology is also popular for art and industrial design and to design organic shapes for medical and healthcare devices.

Software Classification: 

1. High-End
2. Mainstream
3. Hobby

1. High-End Software 

is very common in the automotive and aviation industries and provides a comprehensive solution that includes many specific applications and powerful tools for managing large assemblies with tens of thousands of parts. The high-end software is very expensive and takes a lot of time and experience to specialize.

The three best known High-End Software are:

• PTC Creo (Pro/E) – World’s first solid parametric software.
• Siemens NX – A comprehensive software package widely used in the automotive and aviation industry
• Catia by Dassault Systèmes – A comprehensive software package widely used in the automotive and aviation industry

Autodesk Alias is another high-end software just for surface design. It is common among industrial designers and car designers, difficult to learn and use but packed with fantastic capabilities. If you fantasize about being a car designer, this is the software for you.

2. Mainstream Software  

The most common software for solid parametric design, relatively easy to learn and use. Widely used in engineering and design institutions.

The most popular:

• SolidWorks (Dassault Systèmes) – World’s most popular solid software. Started in 1996 as the first native window 3D software. Relatively easy to use and learn.
• Autodesk Inventor – A good alternative to SolidWorks with advanced tools for free form design
• Solid Edge (Siemens NX) – The first software to combine direct editing with parametric design

The deferment:

SpaceClaim (Ansys) – direct editing solid software very suitable for use in 3D printing. Unskilled users will find it easy and fast to use and with the ability to edit STL files, making it an important tool for preparing models for 3D printing

The new generation:

Onshape – The first 100% cloud solid software. No installation or dependency on your OS, runs on mobile device, tablet or Mac. Easy to use and very modest in hardware resources. Onshape is the best entry tool for the world of design in Solid and is an excellent learning tool for those who wish to continue their professional programs. If you keep your design public, you can try it for free.

Autodesk Fusion 360 – Autodesk is constantly pushing new capabilities to the Fusion 360 cloud computing platform. The software includes endless capabilities for design, simulation and manufacturing. The software requires local installation and uses the cloud as a computational power to perform complex operations more quickly and the cost is very affordable.

Not Solid, hard to use but popular:

Autodesk 3DS MAX – Mesh / polygon software. Highly versatile and widely used software for animation purposes. The MAX is not engineering software and is not as easy to use as the solid software. But it is the only one in the group that allows modeling of characters, animals and other strange forms.

Rhino – A 3D Surface software. Most popular for jewelry design and complex organic shapes.

3. Hobby – Free software for makers:

Programs that provide good 3D capabilities at zero cost. Some of this free software includes surprising capabilities that are not available in the expensive Mainstream software.

Please note that the world of CAD is divided into a number of categories and 3D technologies. In general, Solid software is for mechanical design; Mesh software belongs to the world of animation and organic shapes. With Solid technology, organic shapes can be an impossible task even for an experienced user.

The next two software options have surprising tools and capabilities that can work for an experienced user. Those who are new to the technology will get a great opportunity to learn the basics. They come from leading commercial companies and can be downloaded and used for free without restrictions. Just note, the solid software can eat all your computer resources. Without a powerful processor and enough RAM, the experience can be frustrating.

DesignSpark Mechanical – A “naked” version of the SpaceClaim software branded by RS, a hardware manufacturer. Surprising capabilities and good performance with powerful direct editing software. You can import STEP files and save files to STL for 3D printing. The software continues to be updated and includes the ability to edit and use STL files for further building in Solid, unique capabilities that are hard to find in other software.

PTC Creo Elements – PTC is the inventor of the parametric solid. Several years ago, it acquired HP’s CoCreate software to access the direct editing capabilities that HP software had for years. Elements / direct is a great design software, rich in tools and capabilities and can be downloaded and used for free without time limit. The software is limited to 60 parts in one assembly, more than enough for the amateur designer.

Autodesk 123D Design – Until recently, Autodesk was the only company that took seriously the world of Makers and 3D printing with a collection of 3D (and 2D) software designed for the casual user. Recently, the company retired some of the free projects in the 123D software family and it is not available on the Autodesk web site anymore.

Rush and download the software from the alternative link above as long as it is available.

A few more options to consider:

Tinkercad – Cloud software and a very easy to use one. It uses unique technology, enables the editing of STL files, and is most suitable for old PCs. Tinkercad is an important tool in the toolbox of any home enthusiast who wants to design STL files.

FreeCAD – Open source Solid software. Provides tools to convert file formats and the possibility to work with Mesh files. As a design tool, it can not compete with the other programs mentioned here. FreeCAD has great potential but is unstable and not easy to use.

SketchUP – Popular software with a large user base. Very easy to use, designed primarily for architectural 3D design. It’s very easy to get results with the software for simple projects.

Blender – Powerful animation software. The free equivalent to 3D Max. Using a blender can be frustrating. There are countless examples of amazing models made on the web, but the software requires learning and knowledge. It is difficult to operate and is suitable mainly for those who intend to specialize in the field of animation. If you wish to design dragons and monsters Blender may be exactly the software for you.

Remember, 3D CAD should be fun. If it is not, go ahead and try other software.

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Gal Raz is a 3D printing, additive manufacturing and CAD expert, a senior business developer with over 20 years of experience in 3D and a proven record of developing new markets for CAD and 3D printing solutions. He’s been working with major organizations in the fields of aviation, healthcare, homeland security etc. consulting them how to ad​opt CAD and additive manufacturing technologies. 

Gal Raz has worked in Israel, Singapore, and Australia and is adept at working in a multicultural environment, and he is open to the right opportunity anywhere around the globe, especially if there are nice bicycle trails in the area.