There are plenty of methods of improving print bed adhesion for prints that are likely to warp. One of the most commonly used methods is a raft. Rafts, however, end up consuming a lot of filament for something that will get discarded. They also negatively affect the surface quality of the underside of the print. A brim can be a compelling alternative, offering the same strengths while minimizing the downsides.
What Is a Brim?
A brim is essentially a single layer raft – although they can be multi-layered – that only touches the outside of the print, like the brim of a hat. Alternatively, a brim can be considered a skirt with no gap between the print and skirt. Either way, a brim increases the contact area with the print bed like a raft, increasing the overall adhesion force.
This increase in adhesion helps prevent the warping of filaments prone to that – such as ABS – by holding them down. This allows you to configure the amount of adhesive force and the amount of material you want to use. It is, of course, possible to configure how wide the brim is.
While a brim can provide just the same amount of extra adhesion as a raft, it does so using a significantly reduced amount of material. Rafts tend to be thicker and have more of a structure, and extend completely underneath the print. The fact that a brim only circles the outside of the print minimizes the amount of material that will eventually be disposed of.
Once the print is complete, a raft can be relatively easily removed if done properly. This will, however, negatively affect the surface quality of the entire underside of the print. A brim is arguably easier to remove thanks to reduced contact points, which also minimizes the area that needs to be post-processed to remove artifacts left behind on the print.
As with any disposable material, the removal process runs the risk of damaging the print in a way that can’t just be sanded. Now you know the basics of using a brim when 3D printing, why not try one with your next print. Make sure to let us know if it helps.