3D printer strength


Optimizing Strength of 3D Printed Parts — 3DPros

Whether you are considering 3D printing for prototypes or end use applications, there are many factors you’ll need to consider to ensure the parts are strong enough for your application. In this article, we’ll take a look at the choices which have the greatest impact on part strength:

Note that this guide discusses specific considerations for FDM 3D printing; other 3D printing technologies have differing considerations.

When 3D printing end use parts like this mounting bracket for the cement extruder for our client’s structural 3D printer, part strength is top priority. We used PETG with a high infill and shell thickness to ensure this part was up to the job.

3D Printer Settings

Infill Percentage

When ordering 3D printed parts, you will typically need to specify an infill percentage. Infill Percentage represents how dense the interior of the model will be. This setting ranges from 0%, a totally hollow model, to 100%, a totally solid model. Infill has the greatest impact of compression strength, since it acts to support the interior of the model.

It seems obvious that a totally solid model would be the best choice for strength, but in practice, choosing a value beyond 60-70% has very little impact on part strength and is usually not worth the additional cost and print time. Especially for larger models with large internal spaces, increasing the infill can have a drastic impact on both the cost and print time. It is important to consider whether the benefits outweigh the drawbacks for your application.

Increasing the infill percentage improves the strength of 3D printed parts, especially impact resistance, but the benefits taper beyond 60%.

Refer to our Infill Percentage Guide for more details and other considerations for this setting.

Shell Thickness

Another lesser known setting, the shell thickness, also plays a significant role in part strength. Shell Thickness refers to the thickness of the outer surfaces of the part. Most 3D printing services use a standard thickness of about 1.0 - 1.5 mm, but increasing this setting can greatly increase the tensile strength and impact strength of your parts.

Increasing the shell thickness of parts can significantly improve the strength of 3D printed parts, even with a lower infill percentage.

Material Choice

The material your parts are made from also has a significant impact on strength. Typically, 3D printed parts are made from PLA, ABS, or PETG plastics. Its important to consider the types of force that your parts will undergo when deciding on the most suitable material.

ABS, PETG, and PLA have differing strength characteristics which are important to consider when 3D printing end use parts.

For parts which need tensile strength to resist forces pulling on the object, PETG is the strongest option, followed by PLA. ABS is the least effective choice for resisting this type of force. PETG has especially strong bonding between layers and is stronger than other options, which is why it is an especially good choice for thin parts with high strength requirements.

If your parts are subjected to bending forces, ABS is typically the strongest option due to its ductility, followed by PETG. PLA is more rigid and brittle than the other options, which means it is not a good choice for applications that require flexural resistance.

If parts need to resist impact, such as being subjected to falls, ABS or PETG perform about equally. PLA is less suitable for this use due to its rigidity.

For more information on material options and other considerations, refer to our Materials Guide.

Part Orientation

Part Orientation, or how the part is positioned on the 3D printer, is a strength consideration unique to 3D printing. To understand why the orientation has such a significant impact, you need to know how parts are produced on an FDM 3D printer. Parts are 3D printed by depositing thin layers of melted plastic at gradually increasing heights in order to form a 3 dimensional part.

3D printed parts are created by depositing thin layers of plastic, each slightly higher than the last.

Althought the plastic of each layer bonds to the previous layer, the interfaces between these layers are a weak point. When 3D Printed parts crack or break, it is typically between layer lines.

Considering this characteristic of 3D printed parts is especially useful when forces are subjected on the part in a specific direction. For example, if you were designing a bracket for a shelf, you know that the largest forces will be pushing downward where the bracket attaches to the shelf. Using this information, printing the bracket on its side will ensure that the force is not acting along the interfaces between layers.

In cases where you cannot avoid forces acting across layers, consider using PETG since it has the best layer bonding performance of the common materials.

We printed the same shelf bracket in two different orientations. Which of these do you think will perform better?

The part with a thin interface across layer lines (on the left in the first image) failed with relatively little force.

Keep in mind that other factors can also impact the best choice for part orientation. For example, part orientation affects which surfaces of the print will be smoothest. In some cases, part orientation can also affect the cost of the print because more support material may be required to enable a certain part orientation.

Other Considerations

While you can use the techniques in this guide to improve the strength of your parts, strength is just one of many factors you are likely thinking about when considering 3D printing for your project. Other requirements, such as the appearance of the parts, cost of production, and timeframe, can require you to make difficult trade-offs. If you aren’t sure how to proceed or just want to run your ideas by someone, we would love to hear about your project and help you figure out the best way to print it!

Next Steps

Want to Learn more about buying your own 3D printer?

Our informational site www.crealityexperts.com is a great place to start! We have used Creality brand 3D printers for years and have been very happy with them

Looking to order 3D printed parts?

You can find a local vendor on Treatstock; a site for small 3D printing businesses to list their services. We have worked with them in the past and had great experiences, and we highly recommend them if you are looking to work with a small business

Are 3D Printed Parts Strong & Durable? PLA, ABS & PETG – 3D Printerly

Companies worldwide have recently turned to 3D printing to create technical parts quickly while saving some money in the process. But, developing 3D versions of pieces involves using new materials that might not be as durable. So, are 3D printed parts strong?

3D printed parts are very strong, especially when using specialized filament like PEEK or Polycarbonate, which is used for bullet-proof glass and riot shields. Infill density, wall thickness and print orientation can be adjusted to increase strength.

There’s a lot that goes into the strength of a 3D part. So, we’re going to be reviewing the materials used during 3D printing, how strong they really are, and what you can do to increase the strength of your 3D printed parts.

Are 3D Printed Parts Weaker & Fragile?

No, 3D printed parts aren’t weaker and fragile unless you 3D print them with settings that don’t give strength. Creating a 3D print with a low level of infill, with a weaker material, with a thin wall thickness and low printing temperature is likely to lead to a 3D print that’s weak and fragile.

How Do You Make 3D Printed Parts Stronger?

Most 3D printing materials are rather durable on their own, but there are some things that can be done to increase their overall strength. This mostly comes down to the minor details in the design process.

Most important would have to be manipulating the infill, wall thickness, and the number of walls. So, let’s take a look at how each of these factors can impact the strength of a 3D printed structure.

Increase Infill Density

Infill is what’s used to fill in the walls of a 3D printed part. This is essentially the pattern within the wall that adds to the density of the piece overall. Without any infill, the walls of a 3D part would be completely hollow and rather weak to outside forces.

Infill is a great way to increase the weight of a 3D part, also improving the strength of the part at the same time.

There are plenty of different infill patterns that can be used to improve the strength of a 3D printed piece, including a grid infill or a honeycomb infill. But, just how much infill there is will determine the strength.

For regular 3D parts, up to 25% is likely more than enough. For pieces designed to support weight and impact, closer to 100% is always better.

Increase Number of Walls

Think of the walls of a 3D printed part as the support beams in a house. If a house only has four exterior walls and no support beams or interior walls, just about anything can cause the house to collapse or give under any amount of weight.

In the same way, the strength of a 3D printed piece will only exist where there are walls to support weight and impact. That’s exactly why increasing the number of walls inside a 3D printed piece can increase the strength of the structure.

This is an especially useful strategy when it comes to larger 3D printed parts with a greater surface area.

Increase Wall Thickness

The actual thickness of the walls used in a 3D printed piece will determine how much impact and weight a part can withstand. For the most part, thicker walls will mean a more durable and sturdy piece overall.

But, there does seem to be a point at which it’s difficult to print 3D printed parts when the walls are too thick.

The best part about adjusting the wall thickness is that the thickness can vary based on the area of the part. That means the outside world probably won’t know that you’ve thickened the walls unless they cut your piece in half to dissect it.

Generally speaking, extremely thin walls will be quite flimsy and won’t be able to support any exterior weight without collapsing.

Generally, walls that are at least 1.2mm thick are durable and strong for most materials, but I’d recommend going up to 2mm+ for a higher level of strength.

The Strength of Materials Used to Create 3D Parts

3D printed parts can only be as strong as the material that they’re made of. With that said, some materials are a lot stronger and more durable than others. That’s exactly why the strength of 3D printed parts varies so greatly.

Three of the more common materials used to create 3D parts include PLA, ABS, and PETG. So, let’s discuss what each of these materials is, how they can be used, and how strong they really are.

PLA (Polylactic Acid)

PLA, also known as Polylactic Acid, is perhaps the most popular material used in 3D printing. Not only is it quite cost-effective, but it’s also very easy to use to print parts.

That’s why it’s often used to print plastic containers, medical implants, and packaging materials. In most circumstances, PLA is the strongest material used in 3D printing.

Even though PLA has an impressive tensile strength of about 7,250 psi, the material does tend to be a little brittle in special circumstances. That means it’s a little more likely to break or shatter when placed under a powerful impact.

It’s also important to note that PLA has a relatively low melting point. When exposed to high temperatures, the durability and strength of PLA will severely weaken.

ABS (Acrylonitrile Butadiene Styrene)

ABS, also known as Acrylonitrile Butadiene Styrene, isn’t quite as strong as PLA, but that doesn’t at all mean that it’s a weak 3D printing material. In fact, this material is much more capable of withstanding heavy impact, often flexing and bending rather than shattering completely.

That’s all thanks to the tensile strength of about 4,700 PSI. Given the lightweight construction yet impressive durability, ABS is one of the best 3D printing materials out there.

That’s why ABS is used to make just about any type of product in the world. It’s quite a popular material when it comes to printing children’s toys like Legos, computer parts, and even piping segments.

The incredibly high melting point of ABS also makes it able to withstand just about any amount of heat.

PETG (Polyethylene Terephthalate Glycol-Modified)

PETG, also known as Polyethylene Terephthalate, is usually used to develop more complex designs and objects when it comes to 3D printing. That’s because PETG tends to be much denser, more durable, and more rigid than some of the other 3D printing materials.

For that exact reason, PETG is used to make plenty of products like food containers and signage.

Why Use 3D Printing at All?

If 3D printed parts weren’t at all strong, then they wouldn’t be used as an alternative production method for many supplies and materials.

But, are they as strong as metals like steel and aluminum? Definitely not!

However, they are quite useful when it comes to designing new pieces, printing them at a lower cost, and getting a good amount of durable use out of them. They’re also great for small parts and have a generally decent tensile strength given their size and thickness.

What’s even better is that these 3D printed parts can be manipulated to increase their strength and overall durability.

Conclusion

3D printed parts are definitely strong enough to be used to make common plastic items that can withstand great amounts of impact and even heat. For the most part, ABS tends to be much more durable, though it does have a much lower tensile strength than PLA.

But, you also need to take into consideration what’s being done to make these printed parts even stronger. When you bump up the infill density, increase the number of walls, and improve the wall thickness, you’re adding to the strength and durability of a 3D printed piece.

What is the most durable material for 3D printing?

3DPrintStory