3D Printing Brim: When You Should Use It

Preventing warping, aiding adhesion and reducing waste – what's not to love about a 3D printing edge? Read on to learn more!

Poor adhesion of the first layer can make 3D printing downright impossible. Models with complex geometry can separate from the bed as the print progresses, and warping—which becomes a problem during the print process and isn't obvious from the start—can ruin prints and cost lost time. All these problems can be solved partially or completely with the help of brim (periphery).

Brim is an optional addition to your print and can be enabled in your slicing software. This is not part of your model, but rather a clipping setting to help with the print quality of the first layer of your stamp. Whether you need one depends on the nature of the part you will be printing and the quality of your printer.

There are three different options for add-ons: skirt, raft and brim (skirt, top and periphery). In this article we will focus on brim, discussing when you should use them, when you should avoid them, and how to use them brim properly to get the most out of it.

Let's dive in!

When to use brim?

The periphery is like skirt with 0 mm distance from the model. You can also say it's like raft, which is only one layer at the periphery of the model, but which uses less material, takes less time to print and is easier to remove.

A fringe may not be necessary for every pattern you print. The key is knowing when to use it and when you can do without it. Even in cases where you use brim, the settings of the periphery are important to consider and can affect the overall print result. There is no cure-all when it comes to brim and you need to consider each individual situation.

So, let's check some situations when the periphery is a good decision.

Distortion

Warpage is a problem in 3D printing that causes the first layers of the print to shrink due to the pulling of the layers above. This is something that happens as printing progresses. By the time distortion becomes apparent, you may have already invested a lot of time and material into the print.

Distortion can occur with many filamentary materials, although some are more prone to distortion than others. ABS , for example, is notorious. Poor quality threads are also more prone to warping. In addition to the materials, the actual design of the model can cause this problem. Large flat-bottomed models, for example, may distort during printing.

The use of periphery ( brim) helps with warping because it acts as a mesh to force the bottom of the impression to stay attached to the bed. Similar to how the upper parts of the print can try to pull the base up, periphery will pull it down, holding it in place.

When you want to use brim, to prevent distortion, the number of lines defining the width of the peripheryso, will depend on the surface area of your base layer. The bigger it is, the more lines it should have brim, so that there is enough force to pull the part.

Risk geometries

Imagine printing a standing horse. Each hoof and leg is printed separately, then attached to the body as the print progresses. These small individual parts can loosen due to the slight pulling of the thread with each added layer. It's not unusual for the print to start off without a problem and a few layers up, one of the hoofs separates from the bed. After that, the print is spoiled.

Similarly, parts with prominent curves in the first layer or even sharp corners can have problems sticking to the 3D printer table. This can be solved with brim, which helps hold the geometry in place. If you intend to print a sphere or similar geometry where there is very little surface touching the build plate, the periphery can prevent separation from the build plate.

Small support structures

If a print needs supports, but there isn't enough room to place them because, for example, the part they support is too small, the printer may have trouble placing such small geometry and the supports may not stick properly. Therefore the peripheries can help hold the geometry of the support in the same way as they would with the main stamp. This is because plastic adheres better to itself than to other materials, which is why everything usually goes smoothly after the first coat.

Brim basically takes the brunt of the adhesion effort of the first layer. This way, the actual part to be printed can simply be attached to itself brim.

When you should not use a peripheral

If you are considering brim, to check whether the print bed is properly leveled, whether the filament is extruding or other printing settings, but you don't need actual help to stick the first layer, it's better to use skirt. Uses less material and does not touch the model.

The use of brim is a good way to check the calibration and adhesion of the first layer before starting the actual print. However, brim it can mess with the dimensional accuracy of the parts because it can be clamped too tightly, requiring cutting and possibly sanding.

Edges can negatively affect parts that have a snap function or parts that need to be assembled into other parts. Such parts require high dimensional accuracy, but brim it can actually change the final geometry of your model. It may not be necessary to avoid it completely, but it is important to consider the optimal orientation of the bed in order to maintain the functionality of the print.

In contrast, if you intend to print a figurine where dimensional accuracy is not as important, you can use brim, to help the first layer without affecting the final result at all.

Pros / cons

All that said above, let's look at the pros and cons.

Pluses

• Prevents distortion problems.
• Improves bed adhesion resulting in higher chances of successful printing.
• Uses less material compared to raft and is easier to remove.
• The edges do not change the surface finish of the first layer. When you use raft , the first layer is not as smooth as that which attaches directly to the print bed because a gap must be left between raft and the model to facilitate separation. S brim this is not a problem because it only goes around the model.

Cons

• Depending on how close together the lines are in your first layer, sanding or cutting may be necessary.
• If you have a requirement for dimensional accuracy but need to cut or grind the peripheries, this may negatively affect accuracy.
• Brims produce a quantity of waste material.
• It is possible to break delicate geometries when removing the peripheries, so caution is advised when doing so.

Slicer settings

Depending on the cutting software you use, the setting of the brim may change a little. You'll notice differences between different slicers' approaches to them. In Cura, for example, the settings for brim are among the build plate adhesion settings. In Simplify3D brim is considered an add-on, while in PrusaSlicer it is merged with raft and has its own category of settings, brim and brim.

Cura and PrusaSlicer allow you to have brim only on the outside or on both the outside and the inside of the seal. In Simplify brim it can only be outside. In all three options, you can add an offset to brim. If you enter values around 0.1mm or 0.2mm, you can solve the problem of having to sand your stamp afterwards.

Regardless of the differences, it is easy to understand its essence in any new software with some experience. In the following sections, we will explain in more detail how to set up brim in Girl.

1. Open the “Print settings” panel, then click the “Build Plate Adhesion” tab.
2. Select "Brim" in the "Build Plate Adhesion Type" drop-down menu.
3. In the "Brim Line Count" field, you can specify the width of your periphery by number of lines.

These are the only two settings in the “Basic” settings configuration, but if you check “All” in the drop-down menu next to the “Search Settings” field, there are more several settings to play with.

A few of the settings include "Brim Distance", which is an offset relative to the brim, and "Brim Replaces Support", which replaces the brim supports in low sections that need support. When Brim Replaces Support is not enabled, if the model is a standing cylinder, for example, it will also create a brim on the inside.

Brim Tips

As with everything in 3D printing, there is no one-size-fits-all way to get everything set up and get great results the first time. You need experience and a little analysis to understand what is needed in each case. To help you out, we have some tips to get you started.

Purpose

• Think about the purpose of brim. It matters what you want to achieve with it.
• If you want to print a model containing complex geometry, you don't need much brim.
• If you need to prevent warping, you need more lines, so brim to have the necessary force to pull the bottom layer of the impression.

Size

• The number of lines required is relative to the size of the bottom surface of the print. There is no perfect fixed size of brim.
• If a model measures 10 x 10 x 10 mm, brimwith 5 lines is large enough for all purposes. However, if the model is 230 x 230 x 230 mm and you need brim, to prevent distortion, the 5-line brim may be irrelevant because it will be too small compared to the overall model.

Removal of brim

• The cutting of brim can result in unsightly finishes and sharp edges.
• Try to break brim, without cutting it. You can bend it several times, which will weaken and separate the material.
• Make sure your print is not delicate enough that brim to pull it or break it.

Use of different materials

If you have a printer with two print heads/cores, you can also try to print peripheries s PVA , which is a soluble thread. The periphery will be removed easily. However, since it is water soluble, you may want to consider the environmental impact first.