Businesses across the globe are increasingly turning to 3D assembly modeling as part of their product design cycle. It is an excellent way to save time and reduce errors when it comes to manufacturing products of all types. The freelance experts at Cad Crowd have the experience to create 3D assembly drawings for your project, whatever your needs may be.
We can start with 3D models that you have created yourself, or we can provide our 3D modeling services to develop accurate, highly detailed assembly models. The benefits of using assembly models will be discussed in just a little bit, but it would help to understand these models better if we first talk a bit about 3D models in general.
Surface modeling (sometimes referred to as facet modeling) is the process of generating an image that depicts the outside surface of a solid object. While an object has internal parts, its surface model contains limited information, and even then, information only about the exterior shape. There are two crucial distinctions between a surface model and a solid model (solid modeling will be discussed in just a moment):
The first distinction is that a surface model is only an approximation of the shape of the exterior of the object. This has advantages and disadvantages. One of the benefits is that the image can be initially constructed, and eventually displayed, much more quickly than a solid model using far less of the computer’s processing power. One of the disadvantages is that the dimensions of the engine are stored in memory only as an approximation to the true measurements. This can have serious repercussions when it comes to the joining of the engine components, as the tolerances of those measurements are often critical to the performance and safety of that engine.
Nowadays, thanks to improvements in computer processing power and the increasing sophistication of CAD (Computer-Aided Design) software, the surface of the model can be approximated to a much finer level of detail. In fact, surface modeling software can create tens or even hundreds of thousands of these tiny triangles to approximate the shape of the exterior of the model. And while the level of detail can be so fine that curved surfaces can visually appear to be smoothly curved to the naked eye, it is important to remember that each triangle is actually flat. Regardless of how the surface model appears to a viewer, the surface itself is just a mathematical approximation of its true shape.
The second distinction, as mentioned above, is that a surface model contains no information about the interior of the object. In fact, no information at all is stored about whether any individual point is on the interior, on the surface, or outside of the model in the image. With the right software, you can rotate the object to look at it from any angle, and some programs even contain an “x-ray” viewing feature that treats each of those surface polygons like a piece of glass, allowing you to look inside the model. But there would be nothing to look at.
Solid modeling (sometimes referred to as b-rep modeling, short for boundary representation), as you’ve probably guessed by now, is the process of sculpting a 3D computer image of the entire object. Both the surface and the interior are depicted. To describe solid modeling more thoroughly, let’s revisit the two distinctions outlined above:
Whereas a surface model is only an approximation of the shape of the object, a solid model is described by the CAD software exactly. The object is precisely modeled mathematically in exacting detail. As a result, solid modeling is much more computationally intensive and requires more computer memory than surface modeling. But, this means that the position of every point in a solid model is known exactly, which allows us to view anything that exists either inside or outside of the model. Let’s consider a couple of possibilities.
It’s worth noting that it is possible for a surface model and a solid model to look exactly the same. Don’t be fooled by the fact that the first engine above (the surface model) appears as a wireframe while the second engine (the solid model) appears to have a solid-looking surface. In fact, the image of the second engine has been especially 3D rendered to give it that solid appearance. A surface model can also be rendered to make it appear more solid, more realistic. But even though it would look solid, it would still be a surface model; it wouldn’t be as accurate as a solid model, and it wouldn’t contain the same amount of detailed information.
Now, instead of being solid metal, or a hollow shell, what if the solid model was designed in such a way that it contained information about all the actual internal parts? Then a cutaway view of that model might look something like the image shown here. The exact size and position of every single component would be displayed. It would look like an assembly of all the parts of the model.
Assembly modeling is the process of creating, typically through the use of CAD software, a 3D solid model of a product that includes all of its parts. Often, these components move (slide or rotate) in relation to each other, and a part may itself be composed of other components.
The idea of drawings and models that display component information has been around for a long time. Precursors of assembly drawings are illustrations known as exploded views or exploded drawings – images that show the components of an assembly in a slightly separated fashion but drawn in such a way that they clearly show the relationship of the parts to each other, and to the assembly as a whole.
Exploded drawings can be incredibly complex and detailed but are often used for simpler designs such as the bar-yoke assembly shown here. But as you can imagine, if you tried to depict a jet engine and all of its components as an exploded drawing, it could quickly become so large and complicated that it would be difficult to comprehend or to use effectively.
That’s one of the reasons designers often prefer to use assembly modeling instead. Digital assembly drawings can be manipulated to better display the relationship of the individual components to each other.
It is generally recognized that there are two types of assembly modeling processes – top-down design and bottom-up design. There are hybrids of these two, but most businesses will choose one or the other of these processes, depending on the individual project.
In top-down designs, the big-picture view of the overall product is the starting point. Once the overarching design of the project is firmly established, the assembly model can lay out the specifications of the individual components that need to be produced. Top-down design is particularly useful when the desired attributes of the finished product are known in advance. Individual, customized components, like chains and brackets, can then be designed to ensure the final assembled product will perform in the manner expected.
In bottom-up designs, it is the components that are designed first. They are created to perform desired functions within certain parameters and are designed to work with each other. After the components have been brought together in the assembly model, problems can then be identified and corrected. Bottom-up design is especially efficient if the assembly will contain off-the-shelf components, like Original Equipment Manufacturer (OEM) or aftermarket parts such as pulleys and belts. The assembly model itself can be designed and modified to accommodate the dimensions of these existing components.
Whatever your design methodology, the need for accurate solid assembly models, drawn and updated efficiently and in a timely manner, is critical. You can count on finding a professional within Cad Crowd’s extensive network who is willing to work with your company’s internal processes to provide you with exactly what you need, when you need it.
People all around the world engaged in businesses of all sizes make use of 3D assembly modeling services:
|Consumer-goods manufacturers||Industries of all types|
The use of 3D assembly modeling during product lifecycle management has become mandatory for most industries. And while there are necessary costs associated with implementing this, there are also enormous benefits to be realized. Benefits such as:
Using virtual tools to create assembly models for use during the design and implementation stages of your project can save a significant amount of time. (See, for example, this study.) Time savings can also be realized because each component of an assembly is a distinct 3D model in its own right – several people can be working on a given assembly at the same time, with each person designing or modifying a different component, reducing the overall time needed to finish the overall model.
Through the use of interference checks (often referred to as interference analyses or interface checks), assembly modeling software can be used to ensure that component specifications are accurate. This can result in a great potential for reducing errors that would translate into unusable parts or significantly degraded design performance.
Interference in an assembly can occur when one component bumps into (interferes with) another one while it’s executing its intended function (for example, a belt between two pulleys may rub against another component when the belt is in motion). An interference check will detect this during the design stage of your project. These interface checks can also be used to provide:
Because you’re dealing with assembly drawings built from solid 3D computer models, dimensions, and tolerances of all parts are stored in memory. Assembly models can use this information to ensure that component placement is accurate, resulting in greater assurance that the final product will perform as intended.
For example, a stock bracket may have been chosen to hold another component in place, but the bracket might actually be too large to fit in its intended position. An interference check could be performed by the CAD software that would bring this problem to light well before time and money were wasted during actual production. This naturally translates into:
The amount of information available to you when you utilize assembly modeling, coupled with best engineering practices, can help you to ensure the quality of your products. Assembly modeling software has been designed to help you optimize your product, even before time and money are spent to build a prototype. Some CAD software can even calculate suggested optimization solutions for you (PTC’s Creo Behavioral Modeling is an example).
Modern-day assembly modeling software will help you design better components. It will enable you to design those components to work well together. And the better those components work together within your assembly, the higher the quality of the finished product.
Most CAD software programs allow users to generate a bill of materials (BOM). For the uninitiated, a BOM is just a list of the components that make up your assembled product. This list can contain quite a bit of information, though. BOM information available to those having 3D assembly drawings varies by the specific software used, but can include information like part numbers, quantities, vendor names, and costs. BOMs are usually updated automatically by the program as changes are made to the parts of the assembly.
Having a 3D assembly model of a product makes it much easier to produce variations or make simplifications of your designs. With the right CAD software, you can easily and quickly make modifications or updates to assembly drawings as the criteria for the components or for the assembly as a whole change.
As mentioned above, work on an assembly can be shared among several individuals simultaneously. Some CAD programs have taken this concept to new heights, with the system itself existing online in the cloud. There is no software to install on computers (although mobile devices may need a special app installed for access). Users simply access the system through a web browser, anytime, anywhere in the world with internet access. Project files are also stored in the cloud, which reduces the chances that multiple versions of those files might be stored in different computers.
Regardless of whether work is done online or across a company’s network, the collaboration made possible through multi-user access is vital to innovation and development in your product design. And perhaps the most important benefit of assembly modeling is:
As mentioned above, some companies (Onshape is an example) have built assembly modeling capabilities in the cloud. Project files and associated intellectual property (IP) are stored securely, accessible only to designated users with approved log-in credentials. While it may be impossible to guarantee security regardless of the computer system, storage of data in the cloud is obviously much better than an arrangement where proprietary information is being kept in a desktop or mobile device that could easily be stolen.
However, security for your IP, even outside the cloud, can still be very high. While some software packages (AutoCAD is an example) have security protocols like anti-virus countermeasures built in, the first line of defense within any organization will be a set of network best practices. These practices should cover security essentials such as (but not limited to):
With the proper safeguards in place, your assembly models and all the data associated with them can be secure, especially when compared to the risks associated with storing and sharing paper drawings.
Most of the more powerful CAD software packages that are used to design 3D models can also be used to create assembly drawings. Some of the more popular tools are:
|ANSYS SpaceClaim||Dassault SolidWorks|
|Autodesk AutoCAD||Siemens SolidEdge|
|Autodesk Inventor||SolidFace Technology's SolidFace|
If you’re looking for an assembly modeling freelancer with specific software skills, please let us know when you request a quote.
Cad Crowd has the resources to help you achieve your project goals through the use of 3D assembly modeling services. Professionally drawn, high-quality models will reduce the time it takes and the money you spend to get your new products to market.
We can help you find the assembly modeling services company or freelancer to give you a leg up on your competition. Regardless of the complexity of your assembly models, Cad Crowd has the professional resources to help you manage your projects. Contact us today for a free quote.
Our freelance assembly modeling designers are among the most talented in the industry. Cad Crowd has an extensive network of pre-qualified and vetted freelancers available who can develop assembly models that will help you complete your project on time and under budget. Contact us to obtain a free, no-obligation quote today!