How Do You Design Objects for 3D Printing?

3D printing has gone from a niche activity to mainstream in record time, and it’s not hard to see why. The very nature of 3D printing is convenient in every way. It’s cost-effective, uses far fewer materials, and takes much less time if you know what you’re doing. While hobbyists may want to tackle the steep learning curve on their own, for professionals it makes much more sense to go with mechanical engineering companies like ours.

3D printing is one of the most customizable assets for your business. No matter the object, 3D printing technology can produce it flawlessly thanks to G-code and slicing. This gives small business owners the opportunity to make their products their own, and for hobbyists to reflect their unique personalities in their work. While the end result is certainly favorable, getting there can be a bit tricky and confusing. That’s where companies like ours come in.

How Mechanical Engineering Companies Design 3D Objects

Designing 101

The end-result 3D object will begin as a computer model. Similar to video games and animations that depict 3D objects on 2D screens, 3D printing uses computer-aided design (CAD) software to conceptualize the final product. This step is your easiest opportunity to make changes. Double-check to make sure your dimensions are properly proportioned and that the object will be stable once it’s printed. If you’re using a computer numerical controlled (CNC) machine, this is also when you’ll input the commands.

There are many CAD software programs available online, and each of them starts with common three-dimensional shapes such as spheres and cubes. The program will offer settings and tools that will allow you to shape and tweak the 3D geometrics into the object you want. Every program is a little different and it can be slow-going at first, but all CAD software is built with the same goal in mind. You’ll find that many programs offer tutorials as well.

How To Use CAD Software

Any decent CAD program will have everything you need to manipulate the starting shape into the desired object. Typically, you’ll have model viewing tools that easily allow you to rotate or zoom in/out. Most programs will also have a history tab so you can view all the changes you’ve made thus far and rewind/undo them if necessary. Some programs even possess a history tree so you can view your progress organized by the different parts of the object.

Most CAD programs will have a toolbar that lets you effortlessly toggle between functions while you build the object itself. While separate programs will organize their tools differently, an on-site tutorial should cover this, and it won’t be difficult to catch on. You’ll find everything from assembling and manipulating the shapes to sketching and filling in the finer details.

Reference Geometry

This is an important aspect of CAD software and understanding the building of 3D images. While a computer screen can only show an X and a Y axis, a 3D object by definition must also include a Z axis. This becomes challenging because we’re attempting a three-dimensional object on a two-dimensional screen, and it can get confusing. To help with this and avoid confusion, most CAD programs will include referential geometries.

When a new starting shape is placed on the grid to begin tweaking it into the desired object, it automatically centers around the origin 0,0,0 point. This might look like the top closest corner of a cube, and the sides and bottom of the cube would extend from this point. This is meant to act as your starting position. While for beginners this can be confusing, for mechanical engineering companies like ours, it’s an essential tool that quickens our process.


Those who are drawn to the world of 3D printing and wish to design their own objects are usually artistically competent. The majority of artistic folks feel far more comfortable with 2D art than with 3D. Sketches in the making of 3D objects are a great tool for those who feel this way. This portion of the software is similar to other digital art programs, and computer-based artists may feel more comfortable using this.

In a great many CAD programs, you can choose the sketch option, select the plane on which you want the object to sit, and simply draw a 2D image of that object, which can then be transferred to 3D. Rather than start with the program’s basic starting shapes, you can use this tool to create your own starting shapes. This is the easiest option for more complex or unique 3D objects.

Using Constraints

When you are working on your 2D sketched image, most CAD programs allow for the object to be unconstrained. While this makes the initial sketching stage far easier, it can create problems in later stages. When an unconstrained 2D image is being transferred into 3D, it runs the risk of being altered or distorted. This is because, without proper constraints and dimensions, the program doesn’t know what the object is supposed to look like.

Constraints prevent this from happening by telling the computer exactly how and where the sketched object should be positioned. Mechanical engineering companies know it’s smart to get into the habit of constraining as we create our sketches. The dimension tool is also important for keeping the parts of your object the correct sizes. Together, the constraint tool and the dimension tool keep things properly proportioned and scaled for the next step of the process.

The Transition From 2D to 3D 


This tool allows you to bring a 2D object to 3D in a few simple moves. There are two ways to do this, the first of which lets you pull the object upward so the desired shape looks like it’s sitting atop a block. The second way is to cut the object away, so it looks like a cookie-cutter shape of your object cut out of a block.

All you have to do is make sure your sketch is constrained and pick out a closed loop, then choose the desired height using either dimensions or planes to pick out the positioning you want. In some CAD programs, you also have the option to taper the edges of your object during this step, which is ideal for 3D printers that use injection molding.


Ever wondered how some 3D-printed objects manage flawless curving and streamlined shapes? Lofts are the secret weapon, as they smooth out complicated objects and use algorithms to fill in the gaps across multiple planes.


This is the best option for round or spherical objects. From a closed loop, the revolver tool can rotate that loop on an axis or chosen line. This tool is very customizable, allowing you to set different angles or extension points.


You can take your 2D object and essentially “sweep” it across the plane while clicking and dragging, and it will leave a trail of that object behind. This is great for elongating objects or things like tricky appliance installation parts.

Make sure you have two essential things before you begin a sweep: a defined path to sweep along as well as the defined object itself. Sweeping can be intimidating because it’s so freeform and easy to mess up. That’s why mechanical engineering companies are great options for flawless results in 3D printing.

What Comes Next?

After you have your desired 3D object, you’ll simply convert your CAD to a file that your 3D printer can read and execute. The two most common types of 3D printing files are standard tessellation language (STL) and additive manufacturing file (AMF). STL files may be bigger and take more time due to the number of implemented commands. AMFs are less common but tend to store the commands in a more condensed and convenient manner that requires less data.

After you’ve converted to the best file type for your printer, make sure you set the proper sizing, proportions, and orientation before beginning the physical printing process. After this, you can send the STL file or AMF to the slicing software. This essentially slices up the 3D object into thin layers that the printer will be printing in. This software is doubly important because it contains the G-code, which translates human commands into computer speech that the printer can follow.

The Midwest Designs Guarantee

If you want flawless 3D designs without the hassle of tackling the steep learning curve, Midwest Designs is the best option to consider. We understand your time is valuable, and we won’t be satisfied with a finished product until you are. At our company, we can guarantee top-quality results, the lowest overhead around with zero premiums, and the best support you can find.

We specialize in all your 3D printing needs, from logos and figurines to prototypes and gadgets. Check out the “work” tab on our website to view some of our favorite past projects and see our expertise for yourself!

While some people feel confident tackling digital design and working with CAD software, many of us simply don’t have the time in our schedules to tinker with it. This is especially true for professionals and business owners. We understand this and want to help you succeed with your small business. Commission us here at Midwest Designs LLC for your next 3D printing project today so we can make your concept a reality.