How to Determine If You Need 3D Printing Supports

3D printers have been a tremendous breakthrough for unseasoned inventors and experienced engineers alike. The manufacturing industry is quickly capitalizing on the design possibilities and convenience that additive manufacturing has unlocked.

However, there are also challenges that come along with using 3D printers in design and manufacturing. One of these concerns 3D printing supports. Support structures require time and energy — and they use up valuable printer filaments — but they’re decidedly essential for certain projects.

Explore this guide to determine whether your 3D printing project needs the help of outside supports and how to get the best results.

When Do I Not Need 3D Printing Supports?

There are some situations where you may not need to incorporate 3D printing supports. Here are some of them:

• The design has no bridges, sharp angles, or overhangs: These design elements are your best clue as to whether or not you need 3D printer supports. Imagine the letter “T” and “Y” — does your design have similar overhangs?
• Printer performance negates the requirement: Some 3D printers are simply more advanced than others. You should have the option to run an overhang test — or download one online — to get a sense of how well your printer will perform.
• You have a high-speed printer: Another characteristic of the printer itself that makes a difference is its operational speed. Printers that operate more slowly present a greater risk of bridges or overhangs sagging or breaking during fabrication.

You’re encouraged to take advantage of any available overhang tests. Your printer will be subjected to a range of increasingly difficult overhangs to render, ranging from gentle to severe angles. You’ll be able to pinpoint the precise point where your printer begins to struggle.

When Do I Need to Use 3D Printing Supports?

To determine when you do need 3D printing supports, it’s useful to revise the first point above — you need them for bridges, sharp angles, and overhangs.

Recall the letters “T” and “Y” — these are good visual representations of the sorts of structures that will require the placement of 3D printing supports. You’re looking for any shape that juts out without any support from other elements of the design. These areas may sag under their own weight before they’re fully cured if the printer isn’t instructed to place supports beneath them first.

There are a few handy rules to remember when making this determination. Here are the two most common to keep in mind.

1. The 45-Degree Rule

Imagine that “Y” shape with the arms drawn at 45 degrees off the center line. Anything jutting out at a harsher angle than this won’t receive adequate support from the material beneath it and will almost certainly require 3D printing supports, unless you’ve already met one of the other three criteria named in the previous section.

2. The 55m Bridge Rule

Bridges are another one of the telltale structures that will require the addition of supports. Not all bridges need assistance, however.

Picture the “bridge” between the two upright portions of the letter “H.” In a real-world 3D printing design, if that bridge measures more than 5mm across, you should add supports. Again, this is a general rule — your particular printer may provide better or worse results, but this is a great place to begin your trials.

Now, let’s answer some of the other questions you might have about using 3D printer supports.

What Do I Do If My Design Requires 3D Printing Supports?

You can use your slicer software to provide guidance on using or not using supports. Slicer software is the program that converts your finalized digital model into a functional set of instructions for the printer to execute.

Then again, you might prefer to alter your design to make it easier to print without supports. Check out these ways you can make it happen:

1. Incorporate Chamfers

Chamfers take a flat or rounded overhang with a severe angle and distribute it across several angles instead, measuring less than 45 degrees each.

2. Hide Supports in the Design Itself

It’s possible to use clever designs to make sure the model supports itself without outside aid. For an example of this in practice, take a look at some famous marble sculptures featuring outstretched arms or brandished weapons — more often than not, these are subtly resting on another part of the statue.

3. Reorient the Design

Simply reorienting the design is often the most straightforward method. Again, picture the shape of the letter “Y” or “T.” If we print them as-is, they both have severe overhangs that need attention. However, if we invert them and print them upside-down, no such overhang — nor need for outside supports — exists.

What Are the Downsides of Using 3D Printing Supports?

1. Cost

Adding to the overall material costs is one of the chief disadvantages of relying on supports. For the most part, support structures are thrown away after they’ve served their purpose. Job shops on a budget might lament the material waste — and it’s not ideal in an age of eco-conscious consumerism.

2. Time

Time is another additional expenditure associated with 3D printing supports. Printing additional shapes will take additional time. This could delay your time to market for a new product or cause supply chain hangups with your distribution partners if you don’t plan for it.

3. Additional Processing

3D-printed workpieces require additional processing to remove the supports after the printing has run its course. This takes time, as so does the act of sanding, polishing, and carrying out other finishing processes to ensure the desired level of quality without any artifacts left over from the printing phase.

What Are the Types of 3D Printing Supports?

1. Breakaway Supports

If you’re using a printer with a single extruder, it will probably create breakaway 3D printer supports without any manual intervention. You have the ability to increase or reduce the density of support structures when you use this method, which can help slightly mitigate the cost of using additional material.

2. Accordion or Linear Supports

Linear supports are among the most prevalent types of support used in additive manufacturing today. With this method, the printer attaches upright “pillars” across the breadth of the overhang. It’s a versatile method that works with almost any structure that requires support, but it’s also relatively difficult to remove the supports after printing is done and presents more of a risk of damaging the workpiece.

3. Tree Supports

These tree-like supports limit the amount of contact between the support and the actual design, unlike accordion supports. You’ll want linear supports for anything with a close-to-perfectly-horizontal overhang, but any other angle does better with tree-like supports. They don’t bear as much weight, but they’re a lot easier to remove.

4. Dissolvable Supports

Once you invest in a printer with more than one extruder, even more options become available to you. With the ability to use two different materials at once, you could fabricate the base workpiece with PLA and then use a biodegradable material in the other extruder, like PVA, to create supports that easily wash away. The chief advantage is a close-to-zero chance of damaging the model during removal and processing.

Now You Know All About 3D Printing Supports

Now that you’ve completed this crash course in using support structures with 3D printers, what are you planning to make with this newfound knowledge?