One day, we will be able to press a button and a nearly perfect 3D printed object will appear a few hours later. No fuss, no muss. Sounds great, right!? Although 3D technology has come a long way, there is no magic button yet and every maker will run into a challenge once in a while. But you’re a maker, so you tinker and always figure out a fix.
To help you find fixes a little faster, here’s a few of the common errors you might run into and possible adjustments to solve these problems.
1) Stringing/Oozing
During non-print movements, sometimes filament will ooze from the nozzle and is dragged to the next place. This causes stringing that looks like thin cobwebs between your print and can be a pain to remove.
Enable Retraction: One potential cause of this is your retraction settings aren’t set properly in your slicer program. Luckily this is a simple fix. Every slicer has a feature called retraction which tells your 3d printer to ease pressure in your nozzle and stop filament from coming out between non-print moves. This will prevent the excess material from being dragged from one area of the print to another. When the printing resumes, filament will be pushed out of the nozzle to begin again. If your retraction settings are too high, it may clog your nozzle so you may have to do some experimenting with what works for your printer and the filament you’re using.
One thing to note is the difference in retraction settings for Bowden vs. Direct Drive extruders. Retraction distance determines how much filament is pulled up from the nozzle and should be higher for Bowden extruders because there is more distance in between the nozzle and your drive gear where your filament feeds in. For Direct Drive extruders, the recommended setting is below 2.5mm as anything more can cause a jam. Recommended retraction settings for Bowden extruders are between 1mm and 5mm. If you’re having issues, adjust incrementally by .5mm to find the best setting for your printer and filament. Retraction speed should be set at 30-45mm.
Adjust travel speed for non-print moves: The slower your nozzle moves during non-print moves, the more time filament has to ooze out. Speeding up the nozzle for those movements may help prevent stringing. To see a great example of how to experiment with retraction and nozzle speed, check out the series of test prints that MatterHackers did to figure out the best settings to prevent oozing on their printer. They found that 150mm/s travel speed was ideal for their printer, but this will vary so you may want to play around with this.
Adjust your nozzle temperature: Filament will also have a tendency to ooze from the nozzle when extrusion temperatures are too high. Start by checking the suggested print temperatures for the filament you’re using (this will vary a lot between ABS and PLA). Try adjusting the temperature by 5-10 degrees lower from there and see what gives you the best results.
2) Print not sticking to the bed
One moment your print is doing great, and the next you turn around and the nozzle is dragging your print back and fourth over the bed. It continues to extrude filament that just curls at the nozzle and begins to look like coloured scribbles rather than the beautiful masterpiece you expected.
To achieve solid bed adhesion, it’s all about finding the right settings for the first layer of your print. For great first layer adhesion, make sure you do the following:
Level your bed: Your first layers won’t adhere properly to the bed if the distance between the nozzle and your bed isn’t equal throughout the different points of the print. That’s why it’s important to level your bed. Follow the step by step instructions in our Bed Leveling Guide to make sure it’s done properly!
Adjust your starting Z-axis: Even if your bed is level, you want to make sure your nozzle is the right distance away from the bed for the first layer of your print. You can adjust the nozzle position by hand or your slicer program may have settings to adjust this as well. To do it by hand, move the nozzle to the middle of the print bed and bring your Z-axis to home. You don’t want the nozzle to touch the plate, but it shouldn’t be too far either. A good way to test it is to make sure when the filament goes onto the bed, it is flat not round so it’s “squished” onto the bed. Make adjustments by .05mm and see what works best.
Adjust your bed temperature: The purpose of a heated bed is to try to create an even overall temperature for your print. When filament comes out of the nozzle it is very hot and if it is placed on a cold bed and cools too quickly, it will shrink and could hinder adhesion.For PLA recommended heated bed temperatures are between 35-70C and ABS is around 90-110C.
Use Kapton Tape or Glue: Additional tools to help with bed adhesion include Kapton tape, or glue. One layer of Kapton tape over your bed should do the trick! If you are still having issues, you can put a thin layer of glue over the Kapton tape as well. If the Kapton tape begins to rip after you try to take your print off the bed, you should replace the layer for your next print.
3) Plastic Overheating
As we discussed above, when plastic comes out of the extruder and cools too quickly, it can cause warping which leads to poor bed adhesion. When the plastic doesn’t cool down fast enough, it can lead to poor print quality and undefined design features. How do you find a happy medium where you have good bed adhesion but your filament isn’t so hot that it’s preventing your print from solidifying?
Photo source: Richrap Blog
Lower printing temperature: It may seem obvious, but if you notice your design features aren’t turning out, try lowering the print temperature by 5-10 degrees. This will help the layers cool faster and take form so you can print with more detail.
Increase your cooling fan: Cooling fans help cool down the layers of your print before they begin to melt into each other and potentially change shape. Some printers will have cooling fans built in which you can control with your slicer software and some will need to have an external cooling fan built in. You can also try using a regular fan or handheld to cool down the layers.
Slow down your print speed: When you print slowly, you give each layer time to cool and stick to the bed or previous layer. The great thing is, there aren’t many negative side effects to printing slowly, other than you having to wait longer for it to finish! So you’re not at risk of ruining your print by printing slower. When doing complicated or detailed prints, don’t be afraid to slow it right down.
Other problems?
If you are experiencing problems other than the ones above, check out Simplify3D’s Troubleshooting Guide – it’s an awesome resource and a great place to start looking if you’re experiencing abnormalities in your prints. Keep in mind, it’s always best to experiment with your settings on a test print. That way, you avoid wasting time and filament on a longer more complicated print. Check out these test prints and give them a try!
3D printing is usually a great deal of fun, but it can also be a massive source of rage and frustration. You know that feeling; try as you might, that gosh-darned 3D print won’t turn out right. Why does it keep going wrong?
ALL3DP to the rescue with our comprehensive 3D printing troubleshooting guide. We’ve detailed the 16 most common 3D printing problems, so you can quickly diagnose the issue you’re experiencing, together with a series of recommended solutions.
Read how and when these 3D printing problems occur, and the steps you can take to avoid them in future.
3D Printing Problems #1: Warping
Warping: The front corner of this pyramid has lifted up.
What’s the problem? At the base of the model, the print bends upwards until it’s no longer level with the print platform. This can also result in horizontal cracks in upper parts.
What’s the cause? Warping is a common 3D printing problem, which happens when the first layers of heated plastic are cooling down too rapidly and begun to contract. This causes the edges of the model to bend upwards.
3D printing troubleshooting:
Use a heated print bed to keep the plastic at a temperature just below the point where it gets solid. This is called the “glass transition temperature”. This way, the first layer will stay flat on the print bed.
Increase adhesion of the first layer to the print bed by spreading a tiny film of glue evenly on the bed.
Make sure the level of the print bed has been calibrated properly.
You may consider adding a raft or pads to increase platform adhesion.
Another option is to tweak the cooling fan, so it doesn’t get switched on until after a certain number of layers have been printed, or adjust the percentage so it’s not operating at full power.
Even if your printer has a heated bed, it’s always recommended that you use glue and regularly calibrate the bed level.
3D Printing Problems #2: Elephant Foot
Unsightly bulges at the base.
What’s the problem? The base of the model is slightly bulging outwards, otherwise known as “elephant foot”
What’s the cause? This ungainly effect can also be caused by the weight of the rest of the model pressing down the first layers, when the lower layers haven’t had time to cool back into a solid – particularly when your printer has a heated bed.
3D printing troubleshooting: It’s tricky to find the right balance between getting rid of warping and avoiding the elephant foot effect. To minimize bulges at the base of your model, we recommend leveling the printer bed and moving the nozzle a little further away from the bed (but not too far, otherwise the print won’t stick). Additionally, lower the bed temperature slightly.
If you’ve create the 3D model yourself, put a small chamfer at the bottom of the model. Start with a 5mm and 45º chamfer, and experiment to get the best result.
3D Printing Problems #3: More First Layer Problems
Warping because of the small footprint (left); Uneven first layer (right)
What’s the problem?
The first layer does not stick properly, and some parts come loose.
There are unwanted lines at the bottom.
What’s the cause? These 3D printing problems are typical signs that the print bed hasn’t been leveled properly. If the nozzle is too far away from the bed, the bottom surface often shows unwanted lines, and/or the first layer does not stick. If the nozzle is too close, blobs may be the result.
Also important: the print bed has to be as clean as possible. Fingerprints on the plate can prevent the first layer from sticking to the plate.
3D printing troubleshooting:
Use your printer software to re-level the print bed.
Clean the bed of fingerprints.
Apply a fine film of glue before printing.
3D Printing Problems #4: Lower Parts Shrink
What’s the problem? The lower part of the model caves in.
What’s the cause? This happens when the temperature of the heat bed is too high.
Plastic being heated and extruded behaves like a rubber band. First it expands, and when cooling down it shrinks. The heat from the bed only rises to a certain height (depending on the temperature). Up to this height, the extruded plastic stays warm – and malleable – longer than the plastic layers above the height. This way it may yield under the weight of the upper layers and cave in.
3D printing troubleshooting: A simple tactic here is to reduce the bed heat. In some printers the default bed temperature is 75ºC, whereas the recommended temperature for PLA is 50 – 60ºC. Additionally, set the fan in the printer to fully blow at the lowest height.
When printing small models, we recommend you print two copies or two different objects. This way the print head will take more time to print one layer after the other.
When printing models with a large footprint, do not reduce bed temperature too much — otherwise the edges may warp.
3D Printing Problems #5: Skewed Prints / Shifted Layers / Leaning
Shifted layers in Fred Kahl’s “3D printer hangover”
What’s the problem? The upper layers are shifted.
What’s the cause? This is a mechanical fault with the printer, either because:
The head does not move easily on the X or Y rods.
The rods are not aligned correctly, i.e., they are not 100% square.
One of the pulleys is not fixed properly to the axis.
3D printing troubleshooting:
Turn the printer off and check whether you can move the head easily along the rods with your hands. If the head moves stiffly or it moves more easily in one direction, apply a drop of machine oil to the rod.
To see if the rods are correctly aligned, move the head to the left and the right side of the printer and check that the distance between the sliding blocks and the pulleys are equal on both sides. Repeat this for the front/back of the printer. If you notice misalignment, loosen the screws on the two pulleys of the rod in question. Nudge the sliding block a bit until the rod is aligned again, then tighten the screws. Repeat for the other rod.
Check to see if the screws that hold the pulleys in place are secure, and tighten them if necessary.
3D Printing Problems #6: Layer Misalignment
Flawed layer alignment.
What’s the problem? Some layers in the middle of the objects have shifted.
What’s the cause?
The printer belts aren’t well tightened.
The top plate isn’t fastened and wobbles around independent of the bottom plate.
One of the rods in the Z axis is not perfectly straight.
3D printing troubleshooting:
Check the belts and re-tighten them, if necessary.
Check the top plate and fasten it, if necessary.
Check the Z axis rods and replace them if they’re not 100% straight.
3D Printing Problems #7: Missing Layers
What’s the problem? There are gaps in the model, because some layers have been skipped (in part or completely).
What’s the cause?
The printer failed to provide the amount of plastic required for printing the skipped layers. This is called (temporary) under-extrusion. There may have been a problem with the filament (e.g. the diameter varies), the filament spool, the feeder wheel or a clogged nozzle.
Friction has caused the bed to temporarily get stuck. The cause may be that the vertical rods are not perfectly aligned with the linear bearings.
There is a problem with one of the Z axis rods or bearings. The rod could be distorted, dirty or had been oiled excessively.
3D printing troubleshooting:
Check the rods and bearings for problems and fix them. If there is too much oil, for example, remove it.
If you suspect misalignment of rods and bearings, consult your printer’s documentation to see how to correct it.
Finding the cause for under-extrusion is more cumbersome.
3D Printing Problems #8: Cracks In Tall Objects
What’s the problem? There are cracks on the sides, especially on taller models.
What’s the cause? In higher layers the material cools faster, because the heat from the heated print bed doesn’t reach that high. Because of this, adhesion in the upper layers is lower.
3D printing troubleshooting: Increase the extruder temperature; a good start would be to increase it by 10ºC. Also experiment with increasing the bed temperature by 5 – 10ºC.
3D Printing Problems #9: Pillowing
Pillowing: The top surface shows bumps and/or holes.
What’s the problem? The top surface shows unsightly bumps or even holes.
What’s the cause?
The typical cause is improper cooling.
The top surface is not thick enough.
3D printing troubleshooting:
Set the cooling fans to top speed when the top surfaces are printed.
Make sure the top surfaces are at least 6 layers thick.
3D Printing Problems #10: Stringing
Stringing: Unwanted strings of plastic between the parts of the object.
What’s the problem? There are unsightly strings of plastic between parts of the model.
What’s the cause? When the print head moves over an open area (otherwise known as travel move), some filament has dripped from the nozzle.
3D printing troubleshooting: Most printers have a feature called retraction. When retraction has been enabled, the printer retracts the filament in the nozzle before a travel move. This way, no surplus plastic can drip from the nozzle and produce strings. Make sure you enable retraction in the slicing software for your printer, but be aware that this can prolong the time required to print an object.
3D Printing Problems #11: Under-extrusion
What’s the problem? Under-extrusion is when the printer cannot supply the material needed (or as fast as needed). Under-extrusion results in thin layers, in layers with unwanted gaps, or in missing layers entirely.
What’s the cause? There are several possible causes:
The diameter of the filament used does not match the diameter set in the slicing software.
The amount of material that is extruded is too low because of faulty slicer software settings.
The flow of the material through the extruder is restricted by dirt in the nozzle.
3D printing troubleshooting:
In Simplify3D, you set the filament diameter in the Edit Process Settings dialog.
Check the filament diameter and the diameter setting in the slicing software – correct the software setting, if necessary. The filament diameter is printed on the spool or on the package: if not, measure it using calipers.
If there is no mismatch between actual filament diameter and the software setting, the extrusion multiplier (or flow rate or flow compensation) setting may be too low. Increase the setting in 5% steps and restart printing. In Simplify3D open the Edit Process Settings dialog and go to the Extruder tab – the Extrusion multiplier setting of1.0 corresponds to 100%; in Cura open the Material tab and increase the Flow setting (you may need to enable the Flow setting through the Preferences dialog).
Check to see if there is a partial blockage in the nozzle and remove it.
3D Printing Problems #12: Over-extrusion
What’s the problem? Over-extrusion means that the printer supplies more material than needed. This results in excess material on the outside of the model printed.
What’s the cause? Typically, the Extrusion multiplier or Flow setting in your slicing software is too high (see the section above)
3D printing troubleshooting: Correct the Extrusion multiplier or Flow setting in your printer’s software.
A Flow setting way over 100% in Cura may result in over-extrusion; the Flow setting (right) is only visible when you check the Flow option in the Preferences (left).
3D Printing Problems #13: Gaps in the Top Layers
What’s the problem? There are holes or gaps in the top layers.
What’s the cause? To save print material and to speed printing, the interior of a model is not printed 100% solid. Instead, some kind of infill is printed, typically only 30% of the material, the rest of the model remains hollow. Only the top layers (and the walls and the bottom) are printed 100% solid. The are gaps in the top layers can have these causes:
There are too few solid top layers.
The infill percentage (for the interior) is too low.
The first corrective measure when you notice holes or gaps in the top surface: Increase the number of solid top layers in the slicing software. There should be at least 0.5mm of solid layers (how many layers that means depends on the layer height). The additional solid top layers do not add height to your printed model. When you increase the number from 3 to 5, for example, the last 5 layers are printed solid (instead of 3). In Simplify3D, you increase the number of solid layers on the Layer tab in the Edit Process Settings dialog. In Cura, use the Shell Thickness setting on the Quality tab to increase the solid top layers (plus the solid bottom layers and the outside walls).
When the hollow gaps in the model are too wide, because the infill percentage is only – say – 10 or 20% – the solid layers may sag. If adding more solid top layers does not correct the problem, increase the infill percentage in the slicing software. This will increase the filament consumption. In Simplify3D, the infill options are found on the Infill tab in the Edit Process Settings dialog. In Cura, you’ll find the Infill Density setting on the Infill tab.
To correct underextrusion.
3D Printing Problems #14: Visible Lines in the Bottom Layers
What’s the problem? The bottom layers have visible lines.
What’s the cause? The gap between the nozzle and the print bed is too wide.
3D printing troubleshooting:
In Cura, you can increase the thickness of outer walls and the top and bottom layers.
Make sure your print bed is leveled correctly.
Reduce the height of the very first layer – depending on your printer and the filament used, you may go down to 0.1mm (this, however, requires that the print bed is absolutely level).
How to level the print bed and adjust the gap between the nozzle and the print-bed.
3D Printing Problems #15: Scars on the Top Surface
What looks like scratches is in fact oozing of the filament when the printhead travelled over the piece.
What’s the problem? There are visible scratches and scars on the top surface of the model.
What’s the cause? The marks are caused by the nozzle that moved across the top surface.
They are actual scratches as the nozzle scrapes over the surface.
These marks are plastic oozing caused when the nozzle traveled across the surface (but did not touch the surface).
3D printing troubleshooting:
For the example above the, the Retraction Vertical Lift value in Simplify3D was too low.
To avoid scratches and reduce oozing: Increase the vertical lift (or Z-hop) setting for your printer. This setting controls how far the nozzle is lifted up above the last layer printed when travelling (without printing). In Simplify3D, you change this setting on Extruder tab of the Edit Process Settings dialog; make sure the Retraction option is enabled and increase the Retraction Vertical Lift setting. In Cura, set Enable Retraction and Retraction Distance (in the Preferences dialog) and increase the Retraction Distance value on the Material tab.
To reduce oozing more, force the printer to do a retraction before a travel move. In Simplify3D, disable the Only retract when crossing open spaces and Minimum travel for retraction options on the Advanced tab on the Edit Process settings dialog. In Cura, set the Minimum Travel Distance to 1 and Minimum Extrusion to 0. Please note that this will increase print time.
3D Printing Problems #16: No Filament Comes Out of the Nozzle
What’s the problem? The print bed is empty! There’s no filament coming out of the print-head.
What’s the cause?
The nozzle is clogged by carbonized material from previous print processes.
There is a problem with the feeder. The feeder motor may be defective, the pressure the feeder puts on the filament is too low or the filament has ground.
3D printing troubleshooting:
If the nozzle is clogged, clean it according to the printer manufacturer’s instructions.
If the motor is defective, have it replaced. Consult the printer’s documentation to see how and where to change the pressure settings – and check whether the settings are correct. If the filament has ground down, replace it.
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