Benchy Issues Troubleshooting Step-By-Step Guide

When troubleshooting 3D Benchy prints, focusing on the most common issues can help streamline your diagnostic process. We’ve narrowed it down to four (4) easy troubleshooting steps with eight (8) key problems since these are the most frequent culprits behind print quality issues, making them a practical starting point for most users.

Step 1: Assess the Overall Print Quality

Begin by evaluating the general appearance of the Benchy model. A successful print should closely resemble a small boat with smooth, consistent layers. While minor imperfections such as slight steps on the cabin roof may be acceptable, look for obvious flaws such as warping, layer misalignment, or stringing. This initial assessment provides a good starting point to identify potential problem areas and determine the overall calibration of your printer.

Stringing or Hairy Prints

Stringing, often referred to as “hairy prints,” occurs when fine strands of filament appear between parts of the model, giving it an unwanted fuzzy appearance. This issue typically occurs due to incorrect printing temperatures or retraction settings. Printing at too high a temperature makes the filament overly runny and slow to cool, increasing the likelihood of stringing. Insufficient retraction settings can also contribute by allowing the excess filament to extrude during non-print movements, leading to unwanted strands between parts of the model.

To address stringing, you can increase the retraction distance and speed in your slicer settings to minimize oozing during non-printing movements. Additionally, lowering the printing temperature to stay within the filament’s recommended range can help reduce excessive melting, further preventing the formation of these filament strands.

Warping

Warping occurs when the cooling forces within a printed object exceed the adhesion strength holding it to the build plate. This issue becomes more visible with greater temperature differences within the object or between the printing and room temperatures. Warping typically causes the base of the model to lift from the build plate, resulting in distortion. It is often triggered by poor bed adhesion or rapid cooling of the material. 

To fix this, make sure that the build plate is clean and leveled. Applying a glue stick or painter’s tape helps improve adhesion, while avoiding drafts and keeping a consistent ambient temperature can further reduce the likelihood of warping.

Layer Shifting and Misaligned Layers

Layer shifting occurs when layers become misaligned during printing, resulting in a skewed or stepped appearance in the final benchy model. This problem is typically caused by loose belts, mechanical obstructions, or stepper motor issues. 

To resolve layer shifting, start by tightening the belts to ensure proper tension and checking that pulleys are securely fastened to motor shafts, preferably aligned with the flat side of the motor shaft for optimal grip. Inspect the printer for any obstructions, mechanical issues, or friction, particularly on the affected axis. 

Next, clean and lubricate components like smooth rods, lead screws, or rails, and check for broken bearings. Slow down your print speed, as motors skipping due to high speeds can cause shifting. Adjust jerk and acceleration settings if needed for smoother movement. 

After that, check that the filament is unspooling cleanly, as knots or tangles on the spool can block extruder movement and lead to shifting. If warping or curling is also an issue, ensure that no parts of the print are curling upward to interfere with the HotEnd’s movement. 

Lastly, the stepper motor drivers should be calibrated, and, if necessary, the Vref should be slightly increased for the motor to provide additional strength for accurate and consistent movement.

Pro Tip: If you’re using a Prusa MK3(S), disable silent mode to reduce the likelihood of 3D printing errors like layer shifting or inconsistent extrusion.

Step 2: Examine the Hull Surface

The hull is a key feature to assess, as it highlights your printer’s ability to handle curves and smooth surfaces. Check for an even, rounded appearance with minimal layer lines. Inconsistencies such as ridges, bumps, or rough textures may indicate issues with extrusion, cooling, or mechanical alignment. A clean hull suggests your printer is performing well in maintaining layer adhesion and smooth motion control.

Blobs and 3D Printing Zits

Blobs and 3D printing zits are instances of excess filament accumulating on certain areas of your benchy print. Unlike stringing, these defects are localized and typically occur in specific spots rather than across the entire model. They are often caused by incorrect retraction settings, which allow the additional filament to ooze out and deposit onto the print during non-print movements or layer transitions.

One common culprit is the Z-hop, where the nozzle lifts before retraction or travel. While this feature can be useful, it may encourage blobs at the retraction point. To resolve this, either increase retraction settings or disable Z-hop in your slicer. 

Another issue is that the Z-scar (or “Zipper”) appears as a small blob at the layer change point. While it’s not always possible to eliminate Z-scars entirely, modern slicers allow you to control their placement. Choosing a specific, less noticeable location, such as a corner or the back of the print, can confine these imperfections to a straight line along the Z-axis for a cleaner result.

Moreover, blobs and dents can also occur if your filament absorbs moisture. Steam buildup inside the nozzle can cause the filament to pop, leading to blobs followed by dents from filament shortages. Drying your filament before printing and storing it in an airtight container with desiccants can prevent moisture-related issues. 

Additionally, calibrate the extruder to ensure consistent filament flow and avoid over-extrusion. Adjusting retraction settings to minimize oozing during non-printing movements and enabling coasting in your slicer to reduce pressure buildup before non-print moves can further prevent these defects. 

Overheating

Overheating is one of the most visually unappealing issues in printing a benchy, where parts of the print become deformed due to excessive heat. Signs of overheating include a print that retains its general shape but shows melted or deformed areas, often at points requiring precise detail, such as spikes or overhangs. For example, the tip of a deckhouse may appear molten or saggy, indicating overheating during the print process.

The primary cause of overheating is insufficient cooling, where the filament remains too hot and fails to solidify quickly enough. This allows layers to deform as subsequent layers are added. Proper cooling is important to avoid this issue and ensure that your print maintains its intended shape and structural integrity. 

This can be fixed by increasing the cooling fan speed to help solidify layers more quickly. It is also wise to reduce the print temperature to stay within the filament’s recommended range and prevent excessive melting. Lowering the print speed can also allow layers more time to cool and set properly, improving the quality of overhangs and other delicate features.

Step 3: Inspect the Base Layers

Carefully examine the bottom part of the Benchy, as it reveals critical information about bed adhesion and first-layer setup. A smooth and even bottom surface indicates proper bed leveling and adhesion strength, while defects such as warping, gaps, or uneven textures could signal problems with the print bed temperature, leveling, or Z-offset settings. Fixing these issues ensures a solid foundation for future prints.

Inconsistent Extrusions

Inconsistent extrusion appears as uneven layer widths or gaps in a 3D print, often caused by partial clogs, filament quality issues, or extruder calibration errors. 

To resolve this, start by cleaning the nozzle to remove any clogs that may hinder filament flow. Make sure that you’re using high-quality filament stored in a dry environment to avoid moisture absorption, which can impact print consistency. In addition, calibrate the extruder’s steps per millimeter (e-steps) to ensure precise and accurate filament feeding, resulting in smoother and more consistent prints.

Elephant’s Foot

Elephant’s foot is a classic and common issue in 3D printing where the bottom layers of a 3D print appear slightly wider, creating a flared base. This can be caused by an excessively high bed temperature or the nozzle being too close to the bed during the first layer. 

You can fix it by gradually lowering the heated bed temperature to find the optimal setting for your filament. Adjusting the Z-offset to increase the distance between the nozzle and the bed can also help prevent the material from being overly squished. Also, adding a chamfer to the model’s base in the design stage can counteract flaring and improve the final print’s appearance.

Benchy Hull Line

A Benchy’s hull line is a noticeable defect that appears along the hull of the model, often caused by transitions between print features, such as moving from infill to perimeters. 

Most users address this issue by adjusting the slicer settings to ensure consistent extrusion during these transitions. Fine-tuning the infill and perimeter overlap settings can help smooth out the transitions and minimize visible lines. To add to that, maintaining proper calibration of your printer’s mechanical components ensures smooth and accurate movement, reducing the likelihood of hull line defects.

Step 4: Measuring and Fine-Tune Calibration

Finally, precise measurements are used to evaluate the dimensional accuracy of the Benchy. 

A digital caliper is an ideal tool for this task, allowing you to compare critical dimensions, such as the width and length of the hull, against the model’s specifications with high accuracy. 

Significant discrepancies may require recalibrating the extruder steps per millimeter (e-steps) or adjusting flow rates in your slicer settings. This step ensures your printer is capable of producing models with accurate dimensions, essential for functional or precise projects.