Have you ever had trouble placing magnets in the right spot and figuring out how deep they should go in your printed parts? Installation problems may cause an unstable connection between parts. It can also cause magnets to chip and produce damage. Such issues are indeed common because the installation details really affect how well the parts connect. Magnets are often used to connect parts securely because of their attractive force. Usually, magnets are installed on the connecting surfaces of the parts. By positioning them accurately during installation, their magnetic force, at full strength, is utilised to achieve a strong and reliable bond.We can see that magnets are used in Preischl 3D's design, the D20 Dice Box magnetic. In this design, magnetic attraction is used to hold the two parts tightly together, so they do not easily come apart (see the image below). How can we achieve this snug fit? The key is to keep an appropriate gap between the magnet surface and the cavity surface. Maintaining a proper gap stops protrusion, which can cause bumps or damage. It also lets the magnets operate at full strength. This arrangement ensures a secure fit between the parts. So, controlling the magnet's installation position and depth is crucial for a tight fit.Preischl 3D. (2023). D20 Dice Box magnetic [Photograph]. MakerWorld. Retrieved September 23, 2025, from https://makerworld.com/en/@Preischl3DHowever, in practice, it is common to experience the magnet surface not being flush with the cavity surface. What does this look like? What impact does an unflush installation cause? Let us take a look at it together.There are mainly two types of unflush installations.If the magnet surface is raised above the magnet cavity surface, a gap will form between the mating parts. Such a gap will impact the appearance of the print. It may also cause magnets to collide with each other, causing damage.(see the image below)If the magnet surface is recessed too deeply below the magnet cavity surface, a gap will form between the magnets. Such a gap weakens the magnetic attraction. Consequently, the mating parts do not fit tightly, which affects their performance. In such cases, we can see unflushed surfaces on the connecting surface of the parts.(see the image below)To ensure flush magnet installation, we summarised a few methods below. Let us go through the methods one by one to help you improve installation accuracy and product quality.Use magnets designed with negative tolerancesDesign a clearanceSchedule a pause and embed magnets1. Use magnets designed with negative tolerancesAll manufactured objects have tolerances. It means that actual dimensions may differ slightly from the design specifications. Magnets designed with negative tolerances will not exceed the design specifications. But they might be a bit smaller. Materials cool down and shrink during the FDM print process. It results in the dimensions of the magnet cavity being slightly smaller than the design. So, parts designed with negative tolerances are better suited for 3D printing. This helps achieve a precise fit. The image below shows the assembled model using magnets designed with negative tolerances. As such, we recommend using magnets designed with the negative tolerance from Maker's Supply to boost your print quality. The magnets provided by Maker's Supply offer the following benefits.Globally standardised specifications: This ensures users and creators receive parts with consistent dimensions, preventing compatibility issues.Strict tolerance control: Using negative tolerance to manage material shrinkage in FDM printing. It ensures the installation surface is flush.Moderate magnetic strength: Offers an optimal magnetic strength for easy use. It helps avoid problems during disassembly and reduces the risk of impact-related damage.Usually, when using magnets provided by Maker's Supply, we suggest the following socket dimensions: the magnet socket diameter should be the magnet's diameter plus 0.2 mm, and the socket depth should match the magnet's thickness. For easier and secure installation, please consider applying the methods described in the article 'Ways to Optimise a Magnet Socket'.2. Design a clearanceDesigning a clearance can create extra space for magnet installation. It effectively stops the magnet surface from protruding above the cavity surface. You can consider leaving a gap of around 0.2 mm between the magnet surface and the cavity surface. Meanwhile, add a chamfer to the cavity's outer edge.To leave enough space for installation after slicing, please consider how the layer height and the depth of the clearance relate. The depth of the clearance should be set as an integer multiple of the layer height. For example, if the layer height is 0.12 mm, we suggest a 0.24 mm clearance in depth.A chamfer reduces noticeable sinking and makes the appearance more pleasing. The image below shows how the parts fit after using a clearance design.When the magnet cavity faces downwards, the cavity bottom tends to sag even with bridging or support. This makes the cavity depth smaller than designed. So, we suggest adding an extra layer (about one layer height) to the cavity, on top of the design above. This helps make up for sagging. The image below shows the magnet cavity faces downwards.3. Schedule a pause and embed magnetsScheduling a pause and embedding magnets is also an efficient and stable way to install magnets. Check out IDMyron's design, working mimic chest (with double bottom). Its design uses this method, scheduling a pause and embedding magnets.This method requires stopping the printing process and placing magnets into designated cavities. This way lets you secure the magnets firmly and maintain the contact surfaces flush. You can use this method to enhance installation accuracy. The image below shows the cavity reserved for the magnet.When using this method, you will notice that the printer automatically pauses before printing the selected layer. Please be assured, this is a regular operation. After the printer pauses, please continue putting the magnets into the cavities. Once completed, click the 'Resume' button to continue printing.During the pause, the space for embedding the magnet in a chambered printer (for example, the Bambu model P1S) is limited. If too much force is used to press the magnet into the cavity, it may damage the printed parts or the printer. To reduce this risk and make installation easier, the recommended cavity size below is a bit larger and held in place with glue.How to design and schedule a pause and embed magnets? Let's dive into the detailed procedure together using the model below.Open your CAD software, draw a circle on the surface of the model where you want to install the magnet. We recommend setting the circle’s diameter to be 0.3 mm larger than the magnet’s diameter. Then, extrude the circle downward by the magnet thickness plus 0.4 mm. A blind hole is formed.Design a top layer to seal the blind hole and set its thickness to 0.4 mm. Thus, it forms a cavity.(see the image below)After finishing the magnet cavity design, import the model into Bambu Studio. Then, click 'Preview'.Drag the layer slider on the right downwards to find the top layer of the magnet cavity. Then look downwards to spot the layer right underneath the top layer of the cavity. Right-click the '+' sign on the layer slider and select 'Add Pause'. A pause is scheduled before the chosen layer is printed.NotesAfter resuming printing, the nozzle will move around and above the magnet to complete the remaining layer. If the nozzle is made of steel, it may be attracted by the magnet when passing nearby or overhead, potentially pulling the magnet out of its socket. This can lead to installation failure and may cause the magnet to bump into other printer components or damage the printed part. To reduce this risk, we recommend watching the print until two layers have covered the magnet and the socket is sealed before walking away.To firmly hold the magnet in the socket, we recommend using glue. Please keep the following in mind when using glue.When using glue, please follow the safety instructions. For runny glue, avoid splashing and keep it away from eyes and skin.Please use glue suitable for both metal and plastic. Most commonly available CA (cyanoacrylate) glue is suitable for securing magnets. Among high-viscosity glues, for example, Loctite™ 416 and 3M™ PR100 offer better control over application and help prevent overflow. However, please avoid plastic-specific glue. They do not bond magnets to plastic surfaces effectively.Please control the amount of glue used and avoid excessive overflow. Excess glue could cause the surface to turn white or damage the build bed.Here is the detailed procedure for embedding the magnet. When the printer pauses printing, apply a small amount of glue to the bottom of the magnet cavity. Place the magnet in the cavity. Wait around 1 minute for the glue to harden a bit. Then, click Resume to finish printing.Scheduling a pause and embedding magnets may be uncommon for most users. Therefore, we recommend providing reminders at (but not limited to) the following 3 locations to ensure clear guidance and avoid operational errors.We recommend adding an animated GIF under Model Pictures on the model upload page to remind users to embed magnets and resume printing. The images below show where the animation is placed and how it helps explain this step.Please place detailed instructions in a visible area on the model detail page. The image below shows how to guide users through the steps to pause printing, embed magnets, and resume printing.We recommend using the Text Shape tool in Bambu Studio to place instructional text on the build plate. The image below shows a sample instruction message for the step of embedding magnets and resuming printing.Through the methods and tips shared earlier, we have developed means to address unflush magnet installation. The methods are: using magnets designed with negative tolerances, designing a clearance, and scheduling a pause to embed magnets. These methods will help achieve flush magnet installation and improve installation accuracy and efficiency. Recommended reading[1] DraftID, "Level Up Your 3D Prints with Hidden Magnets! | How To 3D Print Magnets In Your Designs,“ YouTube, 2024[2] Bambu Lab Wiki, ''View slicing information,’‘ 2025[3] Bambu Lab Wiki, ''3D Text,’‘ 2024 These articles might help you as well — take a look!Ways to Optimise a Magnet SocketWays to Reduce Line Detachment in Dome Structures If this guide sparked ideas or felt familiar, share your thoughts in the comments — let’s chat! Like and save if it helped.