Layer Shifting: What Is It?
As we have said, layer shifting is a common problem that occurs with 3D printers, and it is fairly easy to spot. The tell-tale sign of layer shifting is a staircase effect. Your printed object will have misaligned layers that look like a staircase.
Know that the severity of layer shifting can vary. It can occur throughout the print or only in a few spots. The shift between the layers can be a massive gap or just a few millimeters. It could cause the entire object to collapse, or it could only ruin the look. Either way, layer shifting is always noticeable and will ruin your 3D print.
If you want to know you to properly deal with layer shifting, you must realize that layer shifting refers to a problem with the execution of the print, not the model. Layer shifting is when the printer misaligns even when the instructions given to it are correct. If your 3D models have misaligned layers in the computer, then you have a different problem.
Layer Shifting: What Causes It?
Once you understand that layer shifting is an execution problem, it is a straightforward path to deducing that the problem must lie in the printer itself.
In short, layer shifting occurs because 3D printers do not have a feedback system. The 3D printer moves the printhead according to the directions it receives from the slicer software, but if something occurs to interrupt or alter this motion, the printer has no way of knowing. It will continue to print as though nothing had happened, which will result in layer shifting.
Imagine that you are printing an object. Things are going smoothly, but then you accidentally bump into the printer, joggling the print head a bit. The printer has no way of knowing that the print head shifted a few extra millimeters to the left. It continues to move the head in its previous pattern, but now everything has shifted a few millimeters to the left. This is layer shifting.
The printer is essentially blind to the movement of the print head and extruder. It sends instructions but remains unaware if something changes, which is why layer shifting requires manual adjustments to fix.
Unfortunately, there are several different factors besides physically bumping the printer, which can result in layer shifting. You will need to check for the following to determine where the issue occurred and, consequently, how to fix it.
For now, we will simply be discussing what causes layer shifting. We will outline a step-by-step process for identifying these issues in the next section. It is essential that you first know what you are looking for before getting into the steps to fix these issues.
Cause 1: Loose Belts
3D printers have to be precise. Being off by a few millimeters can ruin the print. Because of this need for precision, loose mechanical parts can be a big issue.
One component that can become loose is the belts. If the belts do not have the proper tension, the extruder will slip as it moves. Tightening the belts is a fairly simple process, which we will outline in our step by step maintenance guide.
Cause 2: Pulley Problems
Besides loose belts, pulleys are another mechanical component whose malfunctioning can cause your printer to misalign.
One potential problem with your pulleys is that they may not be properly attached to the machine. If your pulleys are loose, then they may slip and cause the extruder to move. You can tell if your pulley is loose by checking the screws that attach the pulley to your printer. They should be as tight as possible.
The other potential issue that could lie in your pulleys is resistance when they turn. If your pulleys are not turning smoothly, there will be delays in the physical movement of your extruder, which will cause the layer alignment to get off. Resistance in your pulleys likely has other underlying, such as the axis motors, which will require further investigation.
Cause 3: Loose Axis Block Covers
Another potential mechanical issue is loose axis block covers. If the cover on your axis block is loose, the precision of your printer will be affected. There should be two screws that attach the axis block cover. Make sure they are as tight as possible.
Cause 4: Restricted Extruder Motion
If your extruder experiences any delays throughout its movement, the printer will remain unaware and continue producing extrusion at the same speed causing a layer shift.
Similar to restricted pulley rotation, if you notice that your extruder is experiencing restriction or delayed movement at some point in its motion, there is likely a further underlying cause. The delayed movement of the extruder causes the layer shift, but something else has caused the restriction of the extruder, such as a faulty motor. You will need to investigate further.
Cause 5: Print Head Collisions
There is one potential cause of layer shifting that is not a mechanical failure: print head collisions. During its movement, the print head may hit the model and be blocked. Most printers cannot detect a collision and will continue to print despite having been blocked.
We will discuss how to fix print head collisions in the step by step correction guide below.
Cause 6: Printer is Faster than Motor
Sometimes the printer attempts to print faster than the motor can move it. The printer often tries to move past areas where it is not extruding as fast as possible. If the printer thinks it is moving faster than the motor can actually move it, it will begin extruding again at the incorrect place.
Cause 7: Faulty Motor
If you are discovering resistance with your pulleys or extruder, a faulty motor may be the underlying problem. If your motor is not performing at its full competency, then there will be delays and decreased speed with your extruder, which will cause layer shifting.
Cause 8: Endstop Problem
Another thing that can cause layer shifting is an incorrect endstop. Endstops tell the printer when they have reached the end of the row. If these are not working as they should, the printer will end a row at the wrong place, causing them to start everything else from that point in the wrong position.
Cause 9: Overheated Electronics
If none of the other causes is the culprit, then it is likely that your printer is being overworked and some of the electronics have become too hot. The stepper drives, which control the motor’s motion, in particular, will cause issues if they overheat.
Layer Shifting: How Do I Fix It?
With so many potential causes, correcting layer shifting may seem like a gargantuan task. However, using this step by step guide will allow you to find the issue, correct it, and get back to printing in no time!
Since the problem could be any number of the above causes, a step by step approach for checking and correcting each component will allow you to find the issue in the most timely manner. Once you have corrected the layer shifting, there is no need to continue to the next step.
Step 1: Try Decreasing the Print Speed
Before you do anything else, try slowing down your print speed. If the printer is trying to move faster than the motor can handle, your layers will be misaligned.
3D printing takes a long time, and it may be that in trying to speed up the process, you have caused an issue. Therefore, the first step to try is simply decreasing your printer’s speed. By slowing down, your printer may regain the precision it needs to avoid layer shifting.
Step 2: Check for Print Head Collisions
Before you start checking all of your printer’s physical components, make sure that the issue does not lie in the one cause that does not represent a mechanical issue: print head collisions.
Turn your printer back on, and allow it to continue printing, and watch to see if the print head makes contact with the model. You should be able to see if the print head is being blocked by the model.
If this is the case, there are two things you can do to fix it. First, try slowing down the speed of the print head. This should stop it from recklessly bumping into the parts of the print that have already been created.
You can also make a slight adjustment in your slicing software to stop print head collisions. If you add a Z hop, the print head will be lifted before it begins moving on its non-extruding path, ensuring that it does not hit the print while moving to its next position.
Step 3: Turn the Printer Off!
If Steps 1 and 2 did not fix the problem, then it is time to begin a physical inspection.
Hopefully, this was already clear, but for your safety and to avoid damaging the printer, turn your printer off before you start messing with it! There will be times when you need to turn the printer back on to check things, but the first step should be to turn the printer off.
If you end up needing to remove different parts, such as a motor, to inspect them further, take the additional safety precaution of unplugging the printer. You should also unplug the individual piece from the printer.
Most of your inspection will be done with it off. You will only turn the printer back on when you need to make tests. If you locate a problem and apply the recommended fixes, you should then turn the printer back on to test if the layer ending has been corrected. If it has, you can stop. If not, continue to the next step.
Step 4: Clean Your Printer
Now that you know you will need to be checking the mechanical parts of your printer, you should stop the inspection and take the time to clean your printer. Allowing dust and grime to clog your printer can cause all sorts of issues, so since you are going to be examining them anyway, it is an excellent time to wipe the dust off your printer’s parts.
Step 5: Ensure Good Endstop Connection
If you believe the problem is due to an endstop issue, then there is a fast fix. Simply check to make sure that the wires connecting the endstop switches to the motherboard are secure. If they are loose, resecure them and try printing again. If this does not fix the problem, then the layer shifting is likely caused by something else. Move on to the next step.
Step 6: Identify the Axis Where the Shift Occurred
3D printers move along three axes: X, Y, and Z. Layer shifts occur on either the X or the Y-axis (the horizontal plane). Before you do anything else, you need to determine where the layer shift occurred. This will limit the number of components you have to check.
It should be visually clear on what axis the layer shift occurred. The X-axis and Y-axis run perpendicular to each other. The shift will be a movement in a straight line along one of the axes.
Step 7: Tighten the Belts
If your layer shifting is not being caused by a printhead collection, it is time to start checking the mechanical components. Remember that if you have identified the axis where the layer shift is occurring, you only need to check that axis’s component.
The belt is a great place to start. You need to check the belt’s tension. There should be no sagging or give. If there is, you need to correct this.
First, compare the loose belt to a tight one. Does it appear thinner or worn? If so, you may need to replace the belt rather than simply re-tightening it.
If you determine that the belt does not need to be replaced, you will next need to locate the tensioner for this belt’s axis. The x and y-axis have separate tensioners for their respective belts, so check your manual to discover where the one you need is located.
The tensioner can be turned using a tool such as a screwdriver or pliers. Do not attempt to turn the tensioner without using an appropriate tool as you may cause damage! Some 3D printers have knobs here, which will make things easier. Turn the tensioner until the belt is once again tight.
Do not tighten the belt too much. Make sure you are still able to pluck it as too tight belts can cause other issues.
You can also buy belt tensioners for your 3D printer. If you chose to do this, check the product details to make sure the tensioner is compatible with your printer.
Step 8: Check the Pulleys
If the belts are in tight shape, then the next component to check is the pulley. First, see if the pulley is loose. If the pulley can wiggle around, use a screwdriver to tighten the two screws that attach the pulley to the printer.
If the pulley is properly attached, turn it manually to check for resistance. If you are unsure whether there is resistance, try turning the pulley on the axis that is not suffering from a layer shift as a point of comparison.
If you do feel resistance, then check the pulley for any obstructions or materials that may have gotten caught and caused a blockage. If the pulley is clean and free of obstacles, then the resistance is probably due to a motor issue. Skip to Step X to check the axis motor.
Step 9: Wiggle the Axis Block Covers
If the axis block cover is loose, then the axis will jiggle. If you can wiggle the axis block cover, then you will need to take a screwdriver and tighten the two screws which hold this part in place until there is no wiggling.
Step 10: Manually Test Extruder Motion
If none of your mechanical components are loose and slipping, then you need to check the overall extruder motion. With the printer off, manually move the extruder to each corner of the track.
The extruder should be able to move smoothly around all four corners. If you feel resistance, then you will need to do some maintenance. The felt resistance should be obvious if there is a problem, so do not overthink whether you feel it or not.
If you are encountering significant resistance when manually moving the extruder, then you need to either perform axis maintenance (Step 11) or check for a faulty motor (Step 12).
Step 11: Axes Maintenance
If nothing has worked yet, it could be that your axes need some tender loving care. A lack of proper maintenance can result in a guide rail that is not parallel or experiencing a lot of friction.
Guide Rail is Not Parallel
The guide rail which moves the extruder should be parallel to the axis. If it is not, this will cause all movement on that rail to be slightly off. You can check if your guide rail is parallel by using a straight edge to compare the guide rail to the axis,
If you notice that the guide rail is not parallel, you will need to do some maintenance. Before doing anything else, check your printer’s manual to see if there is a guide on how to align the guide rail for your particular model.
A non-parallel guide rail could indicate a problem during assembly or damage to the rail, which would require a replacement. Some guide rail problems can be fixed with jigs such as explained here. The most important thing is to check about your particular model as the methods for fixing this may differ.
Too Much Friction
The other thing that can greatly impede extruder movement is friction. If you believe friction may be the problem, the first step is to thoroughly clean your guide rails and moving parts. Dust or other gunk can cause serious clogs and reduced movement.
Once your parts are clean, you should apply a lubricant to ensure that movement is smooth. Check your printer manual or the manufacturer’s website to see what type of lubricant they recommend for use of their machine.
If you have not been using a lubricant up to this point, your guide rail and other parts may have become damaged over time. If you notice scratches, dents, or other forms of wear, a lubricant may no longer be able to solve the problem. At this point, you need to replace the worn part and ensure that you perform preventative maintenance on the new part.
Step 12: Check for a Faulty Motor
If none of the belts, pulleys, guide rails, or axis block covers are loose or damaged, but your printer is still displaying some sort of movement issue, then the answer likely lies in the motor.
To check the motor, you will first need to carefully remove both axis motors. You will need the motor of the axis where the layer shift did not occur as a reference point to determine if the other is faulty.
Once you have removed the motor, try turning the rotating part manually. It should rotate smoothly. If you are unsure what that should feel like, rotate the other motor manually as well to get an idea of what it should feel like. If the first motor is much harder to turn, it may be faulty.
If you suspect you have a faulty motor, you probably want to make sure before you buy another. You can test your suspicion by switching the motors. Put the X-axis motor on the Y-axis and the Y-axis motor on the X-axis. If the layer shift also switches axes, then the motor is indeed at fault.
Step 13: Keep It Cool
If steps 1 through 12 have yielded no results, it may be that your printer was simply too hot, which caused the motor to skip. To ensure that this does not happen again, make sure your ventilation grates are clean. You can also use a small fan to get more airflow to the motors.
How Do I Prevent Layer Shifting from Happening in the First Place?
Fixing a layer shift issue is great, but it is even better not to have the issue in the first place. What steps can you take to ensure that you do not have to worry about layer shifts at all?
The steps for preventing layer shifting is one step: maintenance. If you perform preventative care on your printer, you are far less likely to find yourself with issues such as layer shifting.
Here are some preventative maintenance steps you can take to prevent layer shifting:
- Dust – Dust causes friction and, if left long enough, can turn into grime that will clog your moving parts. Take the time to wipe your printer off periodically to avoid these issues.
- Lubricate – Save yourself from having to replace worn out parts by lubricating. If the extruder can glide easily along the guide rails, it will cause less wear and tear overall.
- Regularly check belts and pulleys – Over time, your belts will loosen. However, if you remember to check and retighten these periodically, then you will catch the issue before it causes any further problems. Furthermore, if you continue to use a belt that has slipped, the belt will become damaged, and you will have to buy a new one. Do regular check-ups to catch slips early.
- Keep airflow available – Remember to clean your ventilation grates and even provide a fan so that your electronics do not overheat on long jobs.
- Remember that faster isn’t always better – Do not always try to print at the fastest speed possible. If you are facing consistent layer shifting issues and overheating, you may simply be pushing your printer too hard. Slow down, and give your printer time to be precise.