To print anything, your 3D printer needs to know exactly where the entire model is, so it can avoid bumping it and lay the next layer perfectly on top. To do this, it has the entire structure of the model to be printed and assumes that it will stay where it is printed. For this to be true, the print must stick to the print bed firmly. If the print comes loose from the print bed during the printing process, it will fail. Usually with dramatic results that resemble a disorganized bird’s nest or tumbleweed. To prevent this from happening, it is important to ensure that the first layer properly adheres to the print bed.
How to Get Good Print Adhesion
To properly stick your first layer to the print bed, it is important to ensure that the bed itself is level and clean. If the bed isn’t level, then the printer won’t have an accurate view of where the printed material is going, leading to a range of print issues including adhesion problems.
Prints stick to the print bed through a process called wetting. Wetting is the ability of a liquid to conform to the shape of and stick to a solid surface, in this case the print bed. Increasing the contact surface area can really help with this process. There are two main ways to increase surface area; the first is to add texture, the other is to add material.
A rough material has more surface area than a smooth material in the same area; frosted glass is a common print bed material choice as the frosting adds texture. Alternatively, you can use fine-grained sandpaper to make microscopic scratches on the bed surface yourself, or you can add covers such as builders’ tape, glue, or PEI film.
If you have a textured surface, you may want to add more material. You can choose to make a raft or a brim to increase the contact area significantly. Both rafts and brims involve printing an unnecessarily broad first layer. The difference is a brim touches the side of the first layer of the print, whereas, with a raft, the entire print is lifted a layer and printed on top of the raft. Brims are generally easier to remove, thanks to the reduced contact area, they also use less material and are generally preferred over rafts.
As with pretty much everything in 3D printing, the temperature can also have an effect. In this case, the print head temperature doesn’t have as much of an effect. However, with some materials, it is necessary to use a heated print bed. It can really help have higher ambient temperatures. To help manage and stabilize temperatures and to avoid cool breezes, a printer enclosure is recommended. This is generally more necessary for materials with higher printing temperatures.
If a lack of printer bed adhesion has been a sticking point for you, hopefully these tips will help you keep your prints in place. If you have any more tips you’d like to share, let us know down below.