How to Avoid Layer Shifting- 3d Printing Troubleshooting

3D printing comes with loads of advantages and benefits. However, enough time in the business has taught many that it can be a nuisance regardless of the edges. Failed 3D prints can be challenging to resolve without adequate guidance. However, the problem has just a few steps for solutions.

Layer shifting occurs when your 3D print layers do not align as they should. As a result, it creates a staircase look. The staggered appearance of the print is responsible for the name “staircase effect.” The staircase look of the print ultimately renders the entire print useless, although it affects a few print locations.

To be fair, some of the effects have only a minor impression on your print. In this case, the glitches can offset the layers. However, in a serious case scenario, your printer can make a huge mess of things. When this happens, the layers shift, and the objects collapse or tilt in a distorted model, different from the intended result.

Most 3D printers feature an open-loop control system with no feedback from the tool head location. Hence, when the printer moves the tool head, it is done in anticipation that it will move. Powerful stepper motors drive the printer, and when there is no restriction, the tool head moves as it should. Unfortunately, when something goes wrong with the motor, there is no way the printer will pick it up. By implication, whatever causes a misalignment with the tool head can cause a misalignment in your prints.

Put simply; layer shifting means an improper alignment of layers due to a shift in the layers. The usual cause is either when the print head collides with an obstacle or if something else blocks the head. Apart from this, it could occur if the motor cannot match the desired printer’s speed. 

How to avoid layer shifts?

1. Adjust the pulleys and belts

Electrical and mechanical issues with the printer may be responsible for layer shifts. Motors control the tool head positioning in printers that use 3D belts. The belts are made of reinforced fibre and rubber for sturdy performance during use. However, over time, the belt stretches, and the impact can reduce the belt tension. Since the tension affects the tool head positioning, weak tension may cause the belt to slip above the pulley. In essence, the pulley will rotate, but the belt will not move.

In contrast, when the belt is too tight, it may create unnecessary friction that keeps the motors from spinning at the bearings. Apart from the belt, the printers are driven by pulleys attached to the motor shaft with grub screws. Thanks to the screws, the pulley and the motor shaft move in the same motion. However, when the screws are loose, the motor shaft and the pulley may not rotate together.

Hence, although the motor is spinning, the belt and the pulley will not budge. As a result, the tool head won’t reach its destination and will ultimately affect your print layer with its misalignment. Therefore, you should always check the fasteners for alignment. The balance is to tighten the belt moderately without over-tightening it. It should be such that the system can rotate with ease and appropriate tension.  In other words,

• Check the belt tension if your printer has one, to make sure it is not too loose. If it is, replace the belt or print your tensioner.
• Check the pulleys to make sure they are held in place with screws. Since the pulleys are made of toothed pieces of metal, they connect with the belt at special places. Hence, ensure they are screwed tight but not overly tight to avoid unnecessary friction.

More often than, this solution is handy for solving most layer shift problems. One warning, though, be careful with belt tension adjustment and always consult with the manual before proceeding with the adjustment.

Alternatively, you can:

• Observe the direction of the shift by determining the axis where the shift is happening. This way, you will know the exact component (pulleys, motor, belt, etc.) responsible for the shift.
• Check the belt connection with the pulley on the identified axis and check the belt tension. If the tension is not consistent, you should consider maintenance.
• Turn off the printer and manually move the extruder motion. If you detect significant resistance, try extruder maintenance. However, if there is no resistance, check the axis block cover to make sure it is tight. If not, use screws to tighten the cover.
• Manually move the extruder to check if the belt will slip on the pulleys. A worn-out belt or the pulley’s teeth' pressure may cause the belt to slip on the pulley. If this is the case, you may need to replace the belt.
• If the belt does not slip on the pulleys, remove the motor and check the pulley connection. Rotate the pulley to check for manual resistance. If there is, check the resistance of the pulley on the other axes motor to detect differences. If there is a difference, you should replace the faulty motor.
• More importantly, schedule routine maintenance to avoid such problems.

Monitor speed to avoid a collision

The commonest form of collision occurs when the print head collides with something. However, different factors could block the way and cause a collision. For example, when the print head hits a plastic pile-up, it can cause a layer shift.

When you print at a high and fast speed, the motor may not be able to match your printer’s speed. When the motor cannot move as fast as the printer, the printer attempts to cover non-printing space. However, this can cause a problem. In this case, you will hear a clicking sound of the motor trying to fall in the desired position without success. By implication, print misalignment will occur.

Instead of leaving the printer to run any speed, we recommend you reduce the travel speeds. This way, you will reduce the chances of the head colliding with the prints. If you detect an unusually fast printer speed, cut down the speed by 50% and monitor the difference to see if the problem persists. Click the “Edit Process Settings” and choose the Speeds tab to do this. Adjust the “Axis movement speed,” and the “Default Printing Speed” and pay attention to the difference.

The Axis movement speed manages the rapid movement speeds when the system does not extrude plastic. On the other hand, the default printing speed is responsible for the movement speeds where the extruder extrudes plastic. Therefore, if the speed of any is too fast, it can cause a shift. You can try advanced speed settings if you are qualified to try it to scale your printer’s firmware speed up or down.

Alternatively, you can adjust your software settings to move the print head from one part of the print to another part without extruding. Put differently; it means causing the printer to lift the print head before moving. This is because it clears the printer’s nozzle of printed parts to avoid accidents.

Avoid overheating

Although the two solutions above are ideal solutions for avoiding layer shifts, it is not uncommon for both to fail. In this case, it might be because of other common electrical issues. For example, the printer’s electronics could overheat. Not just this, the motor driver electronics may also become too hot and affect the printer’s performance.

This solution is considerably simple as all you need to do is to let your printer cool down before continuing with work. Check to make sure there is adequate ventilation to the motherboard. If the ventilation grills are jammed, it will send the system into an overheating frenzy. Therefore, you should check the ventilation system for signs of jams and inadequacies. Apart from this, you can place a cooling fan near the printer for a direct cooling effect.

Besides overheating, other electronic issues like an insufficient electrical current to the motors can cause a problem. When there is insufficient power, the motors won’t spin as they should. Hence, you can check the power consistency to make sure it is not responsible for the problem.

Conclusion

3D printing sure is an exciting procedure; however, it stems beyond coming up with impressive designs and feeding the machine. If all goes as planned, you won’t have any problem carrying out your routine. However, we know that all doesn’t always go as planned.

Besides learning how to repair layer shifts, it will help, if you understood the basics of the printer you are using. This way, you can carry out routine maintenance when you need to, since you can’t always call for help every time you need one.

On the upside, layer shift on 3D printing is not a common problem. However, it can be annoying when it does come up. As we've explained, you can fix the problem in minutes. We hope you find our guide a helpful way to continue your printing workflow.