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Troubleshooting Guide to 26 Common 3D Printing Problems

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Problems with your 3D printer? Read our 3D printing troubleshooting guide to common 3D printing problems and their solutions.

It’s amazing what your 3D printer can produce. But we’ve all had those infuriating moments when, despite everything, a seemingly simple model just refuses to print successfully.

You’ve checked the model, seen countless others make it without issue, but try as you might it just won’t print. What is it that keeps going wrong?

Here at ALL3DP, we’ve had our fair share of print failures. But the upside to those failures is that we’ve become finely tuned to recognizing and solving many common 3D printing problems.

Direct from our 3D printer troubleshooting experience, we’ve collected together 26 of the most common 3D printing problems and replicated them here.

This article will help you to quickly diagnose your 3D printing issues, and find the solution with our 3D printer troubleshooting guide. Discover how and when these 3D printing problems occur, and the steps you can take to avoid them in future.

Don’t know your problem by name? Flip through the problems by clicking on the headlines.

Troubleshooting Guide to 26 Common 3D Printing Problems

  1. Blocked Bowden Nozzle
  2. Broken Infill
  3. Cracks In Tall Objects
  4. Elephant Foot
  5. Extrusion Temperature Too High
  6. Fine Detail Not Printing Correctly
  7. Gaps between Infill and Outer Wall
  8. Ghosting of the Internal Structure
  9. Layer Misalignment
  10. Leaning Models
  11. Misaligned Layers
  12. Missing Layers
  13. Model Overhangs
  14. More First Layer Problems
  15. Non-Manifold Edges
  16. Nozzle Cleaning with the Cold Pull Method
  17. Over-Extrusion
  18. Pillowing
  19. Poor Surface Quality for Supported Models
  20. Print Dimension Accuracy
  21. Shifting Layers
  22. Snapped filament
  23. Stringing
  24. Stripped filament
  25. Under-Extrusion
  26. Warping

3D Printing Problems #1: Blocked Bowden Nozzle Blocked Bowden Nozzle

What’s the 3D Printing Problem?

You initiate a print job but whatever you try, nothing comes out of the nozzle. Extracting the filament and reinserting doesn’t work.

What’s Causing the 3D Printing Problem?

A small piece of filament has been left behind in the nozzle after changing spools, often because the filament has snapped off at the end. When the new filament is loaded, the piece of old filament that is left in the nozzle doesn’t allow the new filament to be pushed through.

Alternatively, a build up of molten plastic in the end of the nozzle has hardened and will need manual removal. Specialist, cheap or old filaments are a common cause.

3D Printing Troubleshooting: Blocked Bowden Nozzle

3D Printing Troubleshooting Tip #1: Unblock with a needle

If you’re lucky then unblocking can be a quick and easy process. Start by removing the filament. Then using the control panel select the “heat up nozzle” setting and increase to the melting point of the stuck filament. In the case of the Ultimaker 2 go to Maintenance > Heat Up nozzle. For PLA set the temperature to 220 C. Once the nozzle reaches the correct temperature, use a small pin to clear the hole (being careful not to burn your fingers). If your nozzle is 0.4mm then you need a pin that is smaller; an airbrush cleaning kit works perfectly.

3D Printing Troubleshooting Tip #2: Push old filament through

If you find that the nozzle is still blocked then you may be able to push the filament through with another bit of filament. Start by removing the filament as before and then remove the feeder tube from the print head. Heat up the hot end to 220 C for PLA and then using another piece of filament push this through from the top to try to force the stuck filament in the nozzle out. Usually if new filament hasn’t succeeded in unblocking then the extra pressure you can exert by hand might just do the job. However don’t push to hard as you’ll bend the horizontal printer rods.
Once the end clears use a needle to push through the nozzle and a brush to clean any filament excess.

3D Printing Troubleshooting Tip #3: Dismantle and rebuild the hotend

In extreme cases when the nozzle remains blocked, you’ll need to do a little surgery and dismantle the hot end. If you’ve never done this before then it’s a good idea to make notes and take photographs so you know where everything fits when you reassemble. Start by removing the filament, then check your printer’s manual to see exactly how to dismantle the hot end.

3D Printing Problem Checklist: Blocked Bowden Nozzle

  • Heat the nozzle and clean with a needle and brass cleaning brush
  • Remove the feeder tube and try pushing the filament through with another piece of filament
  • Dismantle the hot end and see if you can extract the filament blockage

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3D Printing Problems #2: Broken Infill

What’s the 3D Printing Problem?

The internal structure of your print is missing or broken.

What’s Causing this 3D Printing Problem?

There are a number of reasons for the misprinting of the internal structure. The most common is incorrect settings within the slicing software, but it can also be due to a slightly blocked nozzle.

3D Printing Troubleshooting: Broken Infill

3D Printing Troubleshooting Tip #1: Check the Fill density

In your slicing software check the infill density. A value of around 20% is normal; any less than this and you’re likely to have issues. For larger prints you may want to increase this to ensure that the model has enough support.

3D Printing Troubleshooting Tip #2: Infill Speed

The speed at which the infill is printed can have a major effect on the quality of the structure. If the infill is looking week then decrease the infill print speed.

3D Printing Troubleshooting Tip #3: Change the pattern

Most slicing software enables you to change the internal structure. You can have a grid pattern, or triangle, honeycomb, and more. Try selecting a different option.

3D Printing Troubleshooting Tip #4: Check your nozzle

It might be that there is a slight blockage in the nozzle. While the blockage doesn’t effect the printing of the thicker exterior walls, because there is less flow for the internal structure the filament is getting caught.

3D Printing Problem Checklist: Broken Infill

  • Check and adjust the Fill density
  • Decrease the Infill Speed
  • Try a different infill pattern
  • Check your nozzle for blockages

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3D Printing Problems #3: Cracks In Tall Objects Cracks In Tall Objects

What’s the 3D Printing Problem?

There are cracks on the sides, especially on taller models. This can be one of the most surprising issues in 3D Printing as it tends to manifest itself in larger prints, and usually whilst you’re not looking.

What’s Causing this 3D Printing Problem?

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: Cracks In Tall Objects

3D Printing Troubleshooting Tip #1: Extruder temperature

Start by increasing the extruder temperature; a good start would be to increase it by 10ºC. On the side of your filament box you’ll see the working hot end temperatures, try to keep the temperature adjustment within these values.

3D Printing Troubleshooting Tip #2: Fan direction and speed

Double check your fans, make sure that they’re on and aimed at the model. If they are try reducing their speed.

3D Printing Problem Checklist: Cracks In Tall Objects

  • Check the hot end temperature and raise at 10-degree intervals
  • Check the position and speed of the cooling fans

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3D Printing Problems #4: Elephant Foot Elephant Foot

What’s the 3D Printing Problem?

The base of the model is slightly bulging outwards, otherwise known as “elephant foot”

What’s Causing this 3D Printing Problem?

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: Elephant Foot

3D Printing Troubleshooting Tip #1: The right balance

To stop elephant foot appearing in your 3D prints the base layers of the model need to be cooled sufficiently so that they can support the structure above, but if you apply too much cooling to the base layers you can create warping. Getting the balance right can be tricky, start by lowering the temperature of the print platform by intervals of 5 degrees, (within +/- 20 degrees of the recommended temperature). If your  Bottom / Top Thickness is set to 0.6mm then start the fan after the fan at a slightly lower height.

3D Printing Troubleshooting Tip #2: A level base

More often than not the majority of print issues can be traced back to the level of the print platform. Each printer has a slightly different technique for print platform leveling. Start by using your printers manufacturers recommended procedure. Then print a calibration cube and just watch how the filament is laid down. From printing of the cube you should be able to see if the filament is being laid down evenly, if the nozzle is too close to the print platform and scraping through the molten filament or too high and causing the filament to blob.

3D Printing Troubleshooting Tip #3: Raise the nozzle

Just raising the height of the nozzle slightly can often help, but be careful too high and it won’t stick to the platform.

3D Printing Troubleshooting Tip #4: Chamfer the base

If all else fails then another option is to chamfer the base of your model. Of course, this is only possible if you have either designed the model yourself or you have access to the original file. Start with a 5mm and 45º chamfer, and experiment to get the best result.

3D Printing Problem Checklist: Elephant Foot

  • Balance print platform temperature and fan speed
  • Level the print platform
  • Check the nozzle height
  • Chamfer the model base

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3D Printing Problems #5: Extrusion Temperature Too High Extrusion Temperature Too High

What’s the 3D Printing Problem?

Filament is surprisingly resilient to all types of misconfiguration, including overheating of the hot end. It’s for this reason of resilience that noticing your hot end is too hot isn’t always as easy as you’d think it would be. The effects can be as obvious as discolored filament; in our sample here the dark line that appears half way up 3D Benchy is an obvious sign of scorching where the filament has burnt. This scorching can just appear as slight discoloration or darkening which is less obvious than the dark line above.

Another sign can be the appearance of uneven layers; when you take a closer look you can see that it’s not so much uneven as melted. Again our model shows this subtly on the cabin, and to a far greater effect on the chimney where it starts to look a little like wax running down a melted candle.

Overheating filament can also cause huge issues with accuracy especially when it comes to threadscrew holes. Finding that some holes are correct and others are too small is often an initial sign that the temperature may well be a little too high.

What’s Causing this 3D Printing Problem?

Normally, having too hot a hot end or overheating is an easy fix. The hot end is too hot so you need to cool it down. There needs to be a fine balance between melting the filament so that it will flow, and enabling the filament to solidify quickly so that the next layer can be applied to a solid surface. Before you go adjusting the temperature however, first make sure that you have loaded the correct material settings for your 3D printer (as part of the filament loading process). If you have, then it could be that you need to adjust the temperature just a touch.

3D Printing Troubleshooting: Extruder Temperature Too High

3D Printing Troubleshooting Tip #1: Check the material settings

This might seem obvious, but just double check that you’ve given the printer the correct details about the material. The latest filament temperatures range from between 180 – 260ºC or thereabout, so it’s surprising how easy it is to get this wrong.

3D Printing Troubleshooting Tip #2: Decrease the hot end temperature

In the printer or software settings decrease the hot end temperature. Depending on the severity of the overheating, drop the temperature in 5ºC intervals.

3D Printing Troubleshooting Tip #3: Speed up the print

If the filament isn’t being discoloured then you could try speeding up the print speed.

3D Printing Troubleshooting Tip #4: Check the fans

Check that the cooling fans are directed at the hot end. Check that they’re in the right position and if possible boost their speed to increase airflow over the cooling filament.

3D Printing Problem Checklist: Extruder Temperature Too High

  • Check the material settings
  • Decrease the hot end temperature
  • Speed up the print
  • Check the fan position

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3D Printing Problems #6: Fine Detail Not Printing Correctly 3D Print Problems Fine Detail

What’s the 3D Printing Problem?

Your 3D printer is a finely tuned workhorse able to churn out prints one after another without issue. But then when it comes to a print with fine detail, your printer isn’t producing the results you expect.

Those edges and corners that are supposed to be pinsharp and crisp have a defined curve and softness, and when it comes to fine intricate detail then the quality of the print is a long way from perfect.

What’s Causing this 3D Printing Problem?

There are a number of issues that can affect the quality of printing when it comes to fine detail.

The most common cause of low detail prints is of course the layer height. If you have a low resolution set for your printer then you’re not going to be able to print fine quality, however good your printer is.

Nozzle size is another obvious issue. There’s a very delicate balance between nozzle size and fine print quality. In a production environment the a 0.5mm nozzle is ideal, for general purpose a 0.4mm, and fine detail 0.4mm or smaller.

The smaller nozzle will also mean that your machine will need to be finely tuned as any issues will be amplified.

Nozzle temperature is all important, as your printer needs to be able to extrude the plastic smoothly. When it comes to detail make sure your nozzle is clean prior to starting, even the slightest build up of filament or a small blockage will highlight in the print.

Print speed will also have a huge effect on the detail; for detailed prints go as slow as you dare. You may have to adjust the fan speed to accommodate the increase in extrusion time. Some printers even benefit from the extruder fan being switched to its lowest setting (or even off).

Filament isn’t just filament, quality brands spend a fortune fine tuning their formulas to create a smooth flowing and setting filament. Although cheaper brands might look the same, the tolerances of diameter and content can vary and this inconsistency will again be highlighted in the final print.

Finally check that the print platform is level. Even the slightest error in the level will have reproductions throughout the print when printing at high resolutions. Finding a good calibration print is an easy way of checking just how well your printer is tuned.

3D Printer Troubleshooting: Fine Detail Not Printing Correctly

3D Printing Troubleshooting Tip #1: Increase the resolution

Increase the resolution, a higher resolution will enable you to print finer quality.

3D Printing Troubleshooting Tip #2: Nozzle Diameter

The smaller the nozzle the higher detail you can print. But a small nozzle also means lower tolerances so your machine needs to be highly tuned.

3D Printing Troubleshooting Tip #3: Make sure everything is serviced

Any additional friction from slightly misaligned rods or loose belts will be instantly apparent in your print. Make sure everything is tight and aligned.

3D Printing Troubleshooting Tip #4: Clean your nozzle

Before starting a detailed print make sure that your nozzle is clean any blockage will be instantly apparent.

3D Printing Troubleshooting Tip #5: Slow it down

Reduce the speed of extrusion, a nice slow extrusion is less prone to error.

3D Printing Troubleshooting Tip #6: Use quality filament

Selecting the right material from a quality filament manufacture is a key to good quality prints.

3D Printing Troubleshooting Tip #7: Check platform level

Run through you printers calibration procedure to check that the platform is level.

3D Printing Problem Checklist: Fine Detail Not Printing Correctly

  • Low resolution
  • Nozzle diameter
  • Make sure everything is serviced
  • Clean your nozzle
  • Slow it down
  • Use quality filament
  • Check platform level

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3D Printing Problems #7: Gaps between Infill and Outer Wall

What’s the 3D Printing Problem?

When you look at the top or bottom of the print, you can see a slight gap between the infill and the outer perimeter walls.

What’s Causing this 3D Printing Problem?

Gaps between the perimeter and top layers used to be a common problem, but as printer accuracy has improved and the support for different materials extends, it’s now less of an issue than it was.

However the new wave of advanced materials are far less forgiving than the likes of PLA and ABS, and we’re starting to see a slight resurgence of the problem.
Gaps are caused by the filament used for the infill and outer walls not quite meeting bonding and is a relatively easy fix.

The most obvious cause of the problem is that the infill overlap is not set, or it’s set to “0”. This means that the slicing software is actually telling the printer not to allow the two parts of the print to meet.

Another issue could be the order in which you have set the infill and outer perimeters to be printed. If you’re printing the perimeter first for a high-quality print then there is generally little or no overlap which can again cause the problem.

3D Printing Troubleshooting: Gaps between Infill and Outer Wall

3D Printing Troubleshooting Tip #1: Check the infill overlap

This is by far the most common issue and is really easy to resolve. In your slicing software locate the ‘Infill Overlap’ option and increase the value.

  • In Cura by default this is set to 15% so raise it to 30%.
  • In Simplify3D you’ll find the option in ‘Edit Process Settings > Infill > Outline Overlap’ again increase the value. This setting is directly linked to the extrusion width, so the % value will be a % of whatever you’re extrusion width is. When adjusting this setting always keep it below 50% or you’ll start to see the effects of the overlap in the outer perimeters of your print.

3D Printing Troubleshooting Tip #2: Printing infill before the perimeter

If you’re printing with a relatively thin outer wall the structure of the infill can show through. If this happens then you can switch the order by which the printer lays down the infill and perimeter layers. For example, in Cura check to see if you have ‘Infill prints after perimeters’ ticked.

3D Printing Troubleshooting Tip #3: Increase Hot end temperature

Some of the latest advanced materials such as XT-CF20 are a little less forgiving when it comes to spread due to the carbon fibres that make up part of their structure. When printing with these materials you may find that a slight 5-10º increase in hotend temperature makes all the difference.

3D Printing Troubleshooting Tip #4: Slow it down

Okay, so you may be in a rush to get the printout, but printing at higher speeds can cause all sorts of issues if the printer isn’t perfectly calibrated. If you need to print quick you can still avoid gaps by decreasing the speed of the top layer.

3D Printing Problem Checklist: Gaps between Infill and Outer Wall

  • Check the infill overlap
  • Printing infill before the perimeter
  • Increase hotend temperature
  • Slow it down

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3D Printing Problems #8: Ghosting of the Internal Structure Ghosting of the Internal Structure

What’s the 3D Printing Problem?

The final print looks fine but an outline of the internal support structure can be seen through the walls of the print.

What’s Causing this 3D Printing Problem?

The issue with ghosting happens due to the infill encroaching into the path of the perimeter. This effect is most visible when your print has thin walls. The problems is caused by the infill structure overlapping with the perimeter line as it’s being laid down. Although this ghosting is an issue it’s actually an important part of the printing process, as it helps the internal structure bond effectively to the external walls. Luckily it’s very easy to overcome.

Another cause of ghosting can be that you have set an incorrect wall thickness in relation to the size of nozzle that you’re using. In normal print conditions the size of the nozzle should be directly related to the nozzle size, so if you have a 0.4mm nozzle then the wall thickness should be a multiple of this, either 0.4, 0.8, 0.12 and so forth.

3D Printing Troubleshooting: Ghosting of the Internal Structure

3D Printing Troubleshooting Tip #1: Check the shell thickness

Make sure that the value you have selected for the shell thickness is a multiple of the nozzle size.

3D Printing Troubleshooting Tip #2: Increase the shell thickness

The easiest solution is to increase the shell thickness. By doubling the size it should cover any overlap caused by the infill.

3D Printing Troubleshooting Tip #3: Use Infill after perimeters

Most slicing software will enable you to activate Infill prints after perimeters.

  • In Cura open up the ‘Expert Settings’ and under the Infill section tick the box next to ‘Infill prints after perimeters’
  • In Simply3D Click ‘Edit Process Settings’ then select ‘Layer’ and under ‘Layer Settings’ select ‘Outside-in’ next to the ‘Outline Direction’.

3D Printing Troubleshooting Tip #4: Check print platform

Check around the model and if you see that the effect is more prevalent on one side than the other, the effect could be due to calibration. If so run through the usual calibration process.

3D Printing Troubleshooting Tip #5: Use it to your advantage

Depending on the type of model that you’re printing you can use the internal and shell printing order to your advantage. When you want a high-quality print with a good surface finish where the actual strength of the model isn’t important, select print from the Outside-in. If however the strength of the print is paramount then select Print from in Inside-Out and double the wall thickness. The reason for the difference in strength is that when you print from the Outside-in you eliminate the small amount of overlap that causes the ghosting issue, but this also means that the actual structure won’t create the same strength of bond between the internal and external structure due to the lack of overlap.

3D Printing Problem Checklist: Ghosting of the Internal Structure

  • Check the shell thickness
  • Increase the wall thickness
  • Use Infill after perimeters
  • Check print platform and recalibrate if necessary
  • Use it to your advantag5

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3D Printing Problems #9: Layer Misalignment Layer Misalignment

What’s the 3D Printing Problem?

Some layers in the middle of the objects have shifted.

What’s Causing this 3D Printing Problem?

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: Layer Misalignment

3D Printing Troubleshooting Tip #1: Check the belts

Start by checking each of the belts are tight but not over tight. You should feel a little resistance from the two belts as you pinch them together. If you find that the top section of the belt is tighter than the bottom then this is a sure fire sign that they need a tweak and tighten.

3D Printing Troubleshooting Tip #2: Check the top plate

Check the top plate and all rods and attachments at the top of the printer and make sure everything is tight and aligned.

3D Printing Troubleshooting Tip #3: Check the Z axis rods

Many printers use threaded rods rather than lead screws and although these do the job they do have a tendency to bend over time. Don’t worry about dismantling your printer to see if they’re straight, simply use the software such as ‘Printrun’ to move the print head up or down. If one of the Z axis rods is bent you’ll instantly see. Unfortunately, it’s almost impossible to accurately straighten a rod once it’s bent, but on the upside, it’s a good excuse to replace the old threaded rods for lead screws.

3D Printing Problem Checklist: Layer Misalignment

  • Check the tension in the belts
  • Check there’s no movement in the top plate
  • Make sure the Z axis rods are straight

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3D Printing Problems #10: Leaning Models Leaning Models

What’s the 3D Printing Problem?

As the print forms it starts to lean. Instead of being straight and true, vertical edges are printed at an angle, and this angle isn’t consistent throughout the print. The severity could be increasing and decreasing at different stages.

What’s Causing this 3D Printing Problem?

The cause of the issue is generally very simple; one of the pulleys attached to a stepper motor is slightly loose, or one of the belts is rubbing against something and stopping the full travel of the head. All you need to do to correct the issue is to make sure that none of the pulleys are slipping and the grub screws that hold the pulleys in place are all tightened.

Although this should be a quick and straightforward fix, one issue you may experience as you go to tighten the pulleys is that the small grub screws that tighten onto the shaft of the motor aren’t always that easy to access. Firstly diagnosing which pulley is causing the issue and then getting access to that pulley can be tricky and time-consuming.

3D Printing Troubleshooting: Leaning Models

3D Printing Troubleshooting Tip #1: Check X and Y axis

If your print is leaning to the left or right then you have an X axis issue. Back to front and you have a Y axis problem. Once you’ve diagnosed which it is you can then check the belts and pulleys. If you have a printer such as the PRUSA i3 then the process is pretty straight forward, as the steppers are directly connected to the main drive belt. For the Ultimaker and other printers that process can be a little more tricky.

3D Printing Troubleshooting Tip #2: Check the belts aren’t rubbing

Look round each of the belts and ensure that they’re not rubbing against the side of the machine or any other components. Also check to see that the alignment of the belts is correct. If one is at a slight angle then this can cause issues.

3D Printing Troubleshooting Tip #3: Tighten the stepper motor pulley grub screw

Once you diagnose which axis is causing the issue, use an Allen key to tighten the pulley grub screw that attaches to the stepper motor.

3D Printing Troubleshooting Tip #4: Check rod pulleys

More complex machines such as the Ultimaker 2 have a series of belts and pulleys. The main X, Y rods at the top of the machine feature eight pulleys. Go round each of these on the affected axis and tighten the grub screws for each. It’s unlikely that these will cause any slip but if one is loose then a belt may misalign.

3D Printing Problem Checklist: Leaning Models

  • Check X and Y axis
  • Check the belts aren’t rubbing
  • Tighten the stepper motor pulley grub screw
  • Check rod pulleys and tighten

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3D Printing Problems #11: Misaligned Layers Misaligned Layers

What’s the 3D Printing Problem?

As the print is forming, there appear to be a few issues with the quality. Look closer and you see that the layers aren’t aligning quite as they should. As each line is being laid down neatly side-by-side, you’ll see gaping. Look at the internal support structure and again the pattern looks slightly out, and the outer wall rather than being straight has slight misalignment, causing an uneven rather than smooth face. As you rotate the model around you’ll probably find that the issue only affects the print in one direction; front to back or left to right. By the time the print gets to the top it’s all starting to look a bit messy with strings of filament and a top layer that only partially covers the top of the model.

What’s Causing this 3D Printing Problem?

Over time the parts of your 3D printer — such as nuts, bolts and belts — will become loose and require a tighten. The effect of misaligned layers is similar to the cause of the more pronounced effects of shifting layers and there is no doubt that there is a crossover. If left unchecked, this problem will eventually result in shifting layers, but as the issue starts the visual effect on the prints is far less pronounced and can look very different. The cause is usually linked directly to a loose belt.

3D Printing Troubleshooting: Misaligned Layers

3D Printing Troubleshooting Tip #1: Check belt tension

Start by going around your printer and checking the belt tensions. Use your thumb and index finger to pinch the belts together. If the belts easily touch without putting up any resistance then they’re too loose; when you pinch you should feel a bit of slack at first and then resistance before the two belts touch.

3D Printing Troubleshooting Tip #2: Are top and bottom belts the same?

The printer belts are normally just one continuous loop hooked around two pulleys. A common issue is that over time the belt can slip on one pulley and gradually gets tighter on the top compared with the bottom — or visa versa — and again this can cause issue.

3D Printing Troubleshooting Tip #3: Tighten the belt tensioner

If you own a printer such as the PRUSA i3 then this correction for the X or Y axis really couldn’t be easier. Just tighten the belt tensioners at the front and on the side of the machine. On an Ultimaker the two stepper motors for the X and Y axis can be loosened slightly by untightening the allen key bolts and then pushing down on the motors and re-tightened. If it’s one of the main belts then the belt has probably slipped inside the block that secures the two ends of the belt. If this is the case the block will need to be removed and adjusted before being re-fitted.

3D Printing Problem Checklist: Misaligned Layers

  • Check belt tension
  • Are top and bottom belts the same?
  • Tighten the belt tensioner

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3D Printing Problems #12: Missing Layers Missing Layers

What’s the 3D Printing Problem?

There are gaps in the model because some layers have been skipped (in part or completely).

What’s Causing this 3D Printing Problem?

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: Missing Layers

3D Printing Troubleshooting Tip #1: Mechanical check

It’s good practice to give your 3D Printer the once over every now and again and the appearance of gaps in your 3D print are always a good sign that now is the time to give your 3D printer some love and attention. Start off by checking the rods and make sure that they’re all seated into either bearings or clips and haven’t popped out, shifted or moved even slightly.

3D Printing Troubleshooting Tip #2: Rod alignment Check

Make sure that all rods are still in perfect alignment and haven’t shifted. You can often tell by switching off the power (or disabling steppers) and then gently moving the print head through the X and Y axis. If there is any resistance to the movement then something is wrong and it’s usually pretty easy to tell if this is due to misalignment, a slightly bent rod or one the bearings.

3D Printing Troubleshooting Tip #3: Worn bearing

When bearings go they usually let you know about it by creating an audible din. You should also be able to feel uneven motion in the print head and when printing the machine looks like it’s vibrating slightly. If this is the case unplug the power and move the print head through the X and Y to locate the region of the broken bearing.

3D Printing Troubleshooting Tip #4: Check for oil

Lubricating the joints is easy to forget, but keeping everything well oiled is essential to the smooth running of the machine. Sewing machine oil is ideal and can be purchased for almost any haberdashery at a relatively inexpensively price. Before you go applying liberally just check that the rods are clean and free of dirt and printing debris, a quick wipe of the rods before applying fresh coat of oil is always a good idea. When all rods look clean just dab on a little, but not too much. Then use print such as Printrun to move the head through the X and Y axis to make sure that the rods are evenly covered and moving smoothly. If you add a little too much oil don’t worry just wipe some off with a lint free cloth.

3D Printing Troubleshooting Tip #5: Under-Extrusion

The final issue could be under-extrusion and finding the solution for this can cumbersome. See 3D Printing Problems #9: Under-Extrusion.

3D Printing Problem Checklist: Missing Layers

  • Check over the mechanics and make sure everything is tight
  • Double check the printer’s construction and alignment
  • Listen out for worn bearings and bent rods
  • Add a little oil to keep things running smooth

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3D Printing Problems #13: Model Overhangs

What’s the 3D Printing Problem?

You load your print into your slicing software and everything looks good. Hit print and you find that some parts of the model print absolutely fine, whilst other parts end up as a stringy mess. OK this might seem obvious and the issue of overhangs is often seen as a 3D printing rookie mistake. But it’s surprising just how often even experienced 3D printers are hit with an overhang issue.

What’s Causing this 3D Printing Problem?

The process of FFF requires that each layer is built upon another. It therefore should be obvious that if your model has a section of the print that has nothing below, then the filament will be extruded into thin air and will just end up as a stringy mess rather than an integral part of the print.

Really the slicer software should highlight that this will happen. But most slicer software will just let us go ahead and print without highlighting that the model requires some type of support structure.

3D Printing Troubleshooting: Model Overhangs

3D Printing Troubleshooting Tip #1: Add supports

The quickest and simplest solution is to add supports. Most slicing software will enable you to do this quickly. In Simplify3D click Edit Process Settings > Support > Generate support material; you can the adjust the amount, pattern and settings. In Cura just click the Support type from the Basic settings.

3D Printing Troubleshooting Tip #2: Create in model supports

Supports generated by software can be intrusive so creating your own in your modeling application is a good alternative. It takes a bit more skill but can enable some fantastic results.

3D Printing Troubleshooting Tip #3: Create a support platform

When printing a figure, arms and other extrusions are the most common areas that cause problems. Using supports from the print bed can also cause issues as they often have to span quite large vertical distances; for structures that are supposed to be easily removed and fragile, this distance is prime for causing problems. Creating a solid block or wall under arms etc and then creating a smaller support between the arm and block can be a great solution.

3D Printing Troubleshooting Tip #4: Angle the walls

If you have a shelf style overhang then an easy solution is to slope the wall at 45º so that the wall actually supports itself and removes the need for any other type of support.

3D Printing Troubleshooting Tip #5: Break the part apart

Another way to look at the model is to break it apart and rather than print in one section make two. With some models this enables you to flip what would be an overhang and make instead make it a base. The only issue with this is that you then have to find a way of sticking the two parts back together.

3D Printing Problem Checklist: Model Overhangs

  • Add supports
  • Create in model supports
  • Create a support platform
  • Angle the walls
  • Separate the model and print smaller part3

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3D Printing Problems #14: More First Layer Problems More First Layer Problems

What’s the 3D Printing Problem?

The first layer does not stick properly, and some parts come loose. There are unwanted lines at the bottom.

What’s Causing this 3D Printing Problem?

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: More First Layer Issues

3D Printing Troubleshooting Tip #1: Level the print bed

Every printer has a different process for print platform leveling, some like the latest Lulzbots utilize an extremely reliable auto leveling system, others such as the Ultimaker have a handy step-by-step approach that guides you through the adjustment process and then there’s the Prusa i3 that takes skill and determination.

3D Printing Troubleshooting Tip #2: Adjust the nozzle height

If the nozzle is too high then the filament won’t stick to the platform, to low and the nozzle will actually start to scrape the print off.

3D Printing Troubleshooting Tip #3: Clean the print platform

Every so often it’s a good idea to give the glass print platform a good clean, especially if you apply glue. The grease from your fingerprints and the excessive build up of glue deposits can all contribute to the nonstickiness of the print platform.

3D Printing Troubleshooting Tip #4: Add glue

Applying a thin layer of glue to the print platform will help add a little more adhesion if you do this make sure you give the bed a clean at regular intervals as the over application of glue can have the reverse of the desired effect.

3D Printing Troubleshooting Tip #5: Textured sheet for cold print beds

On cold print platforms, a common solution is to apply a stick-on film or sheet that increases the adhesive properties of the print platform.

3D Printing Problem Checklist: More First Layer Issues

  • Level the print platform
  • Check nozzle height
  • Clean print platform
  • Add Glue
  • Textured sheets for cold platforms

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3D Printing Problems #15: Non-Manifold Edges Non-Manifold Edges

What’s the 3D Printing Problem?

Parts of your print are missing or the final print is weak and falls apart despite the exterior quality of the print looking fine. Sections of the print look completely different from the print preview or the final print has geometry errors that make no sense.

What’s Causing this 3D Printing Problem?

Non-manifold edge are the common cause of misshapen or odd prints. Non-manifold edges are the edges of models that can only exist in the 3D space and not the physical world.

For example if you have two cubes in the real world and try to overlap them directly, it’s physically impossible as the solid outer walls prevent the two objects from intersecting.

In the 3D world you can simply intersect the two, they still exist as individual objects, but the software we use also enables them to intersect in the virtual world.

In order to get the two to print correctly the objects need to be merged so that any inner walls are removed and an object with a single undivided inner cavity is left.

Another common cause is if you have an object such as a cube and delete one of the surfaces. You essentially have an object with a hole, it might look like a shape with five sides, but it only exists in the virtual 3D space, this is geometry with no physical form.

Although you can see the outer walls in the software, the walls that meet the hole only have dimensions in two axis. The third dimension which we see as the thickness of the wall is only illustrative and has no real physical dimension. When it comes to slicing the model the software does it’s best and in many cases will repair the hole, however in more complex models the effects can be interesting to say the least.

3D Printing Troubleshooting: Non-Manifold Edges

3D Printing Troubleshooting Tip #1: Use latest slicer software

Most of the latest slicer engines all support the automatic fixing of non-manifold edges but it’s still good practice to ensure that your models are correctly formed and print ready.

3D Printing Troubleshooting Tip 2: Fix in Horrible in Cura

In Cura open Expert Settings and make sure that under ‘Fix Horrible’ you have Combine everything (Type-A) ticked.

3D Printing Troubleshooting Tip #3: Fix ‘Non-manifold’ in Silmplify3D

In edit ‘Process settings’ click the ‘Advanced’ tab and select ‘Heal’ next to ‘Non-manifold segments.

3D Printing Troubleshooting Tip #4: Use the layer view

In your slicer software use the layer view to check through the model so you can see where the issues appear. A quick slide through the layers will often highlight an easy to fix problem.

3D Printing Troubleshooting Tip #5: Use software to fix issues

One of the easiest ways to fix models with non-manifold edges is to use software; Blender and Meshmixer both have features built in that will quickly enable you to highlight problems with your models and fix them prior to slicing.

3D Printing Troubleshooting Tip #6: Merge objects

Really it’s better to fix your 3D models prior to importing them into your slicing software. To do this, make sure that when you have two objects that do intersect or overlap you choose the appropriate Boolean function to either intersect, merge or subtract.

3D Printing Problem Checklist: Non-Manifold Edges

  • Keep your slicer software up to date
  • “Fix Horrible” (in Cura)
  • “Fix Non-manifold” (in Simplify3D)
  • Use the layer view to check for mistakes
  • Use software like Blender or Meshmixer to fix issues
  • Merge objects

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3D Printing Problems #16: Nozzle Cleaning with the Cold Pull Method Nozzle Cleaning with the Cold Pull Method

What’s the 3D Printing Problem?

Like any machine, a 3D printer needs to be maintained. Sure, some printers need less maintenance than others, but they all need to be looked after. Consumables, moving parts and hot ends can all contribute to problems; essentially, the more you use your printer and the older it gets the more attention it’s going to need.

Regularly checking your machine over, giving it a bit of oil and making sure everything is tight are simple but effective solutions for prolonging the life of your printer. More time consuming but equally important is making sure that your nozzle is clean.

Nozzle cleaning should be at the top of the maintenance list, and as we start to see more dual extruders the need for nozzle cleaning will become even more important. Essentially a good nozzle clean will ensure that your printer continues extruding smooth fluid filament.

A contaminated nozzle isn’t going to be obvious, in fact your printer will probably work perfectly well with a small build-up of carbonised filament welded to the inside of your nozzle. It can and will sit there for weeks or even months without you realising, but there will be small signs in the quality of your prints.

The effects are often overlooked; such as small nicks in the outer walls, small flecks of dark filament or small changes in print quality between models. These defects are often simply put down to the slight variants we come to expect from 3D printers, but really there could be something a little more sinister going on.

What’s Causing this 3D Printing Problem?

It’s inevitable that if you’re heating and cooling different types of filament within your printer there’s going to be a little residue left by each.

If you switch from a PLA to ABS, for example, then if a small amount of PLA is left in the nozzle it will heated beyond its normal melting point. That can mean it will carbonise and burn.

Likewise, switch between ABS and Nylon and again you’ll probably witness something similar. It’s not uncommon to see a wisp of smoke appear briefly as the new filament is fed through.

This carbonised filament burns to the inside of the nozzle and builds up over time, causing issues when it comes to smooth extrusion. To fix, we have to take a look at what is known as the cold pull method.

3D Printing Troubleshooting: Nozzle Cleaning with the Cold Pull Method

3D Printing Troubleshooting Tip #1: Choose your material

You can use ABS or Nylon for this, but over time we’ve found that the most consistent results come from Nylon due to its higher melting point. The filament also holds its shape far better. ABS is more common however, so we’ll use it here.

3D Printing Troubleshooting Tip #2: Remove filament

Start by removing the filament that’s already in the print head in the usual way for your printer. Then remove the Bowden tube or release the direct drive, so that when the time comes you can manually feed the filament through.

3D Printing Troubleshooting Tip #3: Increase the nozzle temperature

Increase the nozzle temperature to 240 degrees. We’re using ABS, but if using Nylon check the melting point temperature on the packaging. Leave it at this temperature for 5 minutes without pushing the filament through.

3D Printing Troubleshooting Tip #4: Push the filament through

Slowly apply pressure to the filament until it starts to come out of the nozzle. Pull it back slightly and push it back through again until it starts to flow from the nozzle.

3D Printing Troubleshooting Tip #5: Reduce the nozzle temperature

Reduce the temperature to 180 degrees for ABS or 140 degrees for Nylon (you’ll need to experiment a little for your filament). Leave the printer at this temperature for 5 minutes.

3D Printing Troubleshooting Tip #6: Extract the filament

Pull out the filament from the head. When you look at the end you should see some black carbonised material at the end. Repeat the process until clean. If the filament won’t pull from the nozzle, increase the hot end slightly.

3D Printing Problem Checklist: Nozzle Cleaning with the Cold Pull Method

  • Choose your material
  • Remove filament
  • Increase the nozzle temperature
  • Push the filament through.
  • Reduce the nozzle temperature
  • Extract the filament

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3D Printing Problems #17: Over-Extrusion

What’s the 3D Printing 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 Causing this 3D Printing Problem?

Typically, the Extrusion multiplier or Flow setting in your slicing software is too high (see the section above)

3D Printing Troubleshooting: Over-Extrusion

3D Printing Troubleshooting Tip #1: Extrusion multiplier

Open your slicer software and check that you have the correct Extrusion multiplier selected.

3D Printing Troubleshooting Tip #2: Flow setting

If that all looks correct then decrease the Flow setting in your printer’s software.

3D Printing Problem Checklist: Over-Extrusion

  • Check you have the right extrusion multiplier settings
  • Decrease the filament flow settings

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3D Printing Problems #18: Pillowing

What’s the 3D Printing Problem?

The top surface of the print shows unsightly bumps or even holes.

What’s Causing this 3D Printing Problem?

The two most common causes are improper cooling of the top layer and that the top surface isn’t thick enough.

3D Printing Troubleshooting: Pillowing

3D Printing Troubleshooting Tip #1: Filament size

More common with 1.75 mm filament. Pillowing is an issue that can affect all 3D printers, however, it’s far more common on those using 1.75 mm filament over 2.85mm.

3D Printing Troubleshooting Tip #2: Check the fan position

Cooling is normally the issue start by checking your fans. As the print starts your printers fans will be set to low or off, after the first few layers have printed they should kick into action. Check that the fans around the hotend start to spin, then as the print finishes check the fans are all good and working. If all seems OK just double check that the direction of the fans is correct and that they’re pushing cool air towards your print and not elsewhere.

3D Printing Troubleshooting Tip #3: Set fan speed in G-Code

Another cooling issue happens when each successive top layer of molten plastic is applied. As it covers the inner support structure it needs to be cooled quickly to avoid falling into the holes between the supports. The speed of the fans can be adjusted in the G-Code, a common G-Code for Fan On is M106 and is M107 Fan Off. You then just need to the Fan speed to maximum for those top layers.
An example would for a 1cm x 1cm cube printer at 0.1mm layer height. The G-Code in this case output through CURA for the Prusa i3, we can look through the code and see that there are 97 layers. Knowing that we have a ‘Bottom / Top Thickness setting’ of 0.6mm we can look back to ;LAYER:91 then in the line after add M106 S255. M106 sets the fan going and S255 sets it to full blast.

3D Printing Troubleshooting Tip #4: Increase top layer thickness

The easiest solution is to increase the top layer thickness. Most applications will enable you to do this in the advanced section, under the ‘Bottom / Top Thickness setting’. You’re aiming for at least 6 layers of material normally and up to 8 for smaller nozzles and filament. If your layer height is therefore set to 0.1mm then set the ‘Bottom / Top Thickness setting’ to 0.6mm. If the effect of pillowing still exists then increase to 0.8mm.

3D Printing Problem Checklist: Pillowing

  • Go large and increase the filament size
  • Make sure the fans are up to speed and positioned
  • Manually set the fan speed
  • Increase the top layer thickness

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3D Printing Problems #19: Poor Surface Quality for Supported Models

What’s the 3D Printing Problem?

You’ve printed a complex model with supports created with your chosen software. But when it comes to removing the structure, small remnants of material are left on the surface. When you try to sand or remove the remaining material, it ruins the overall effect of the model.

What’s Causing this 3D Printing Problem?

Supports are an essential part of 3D modelling and a subject that can divide opinion. Many models can actually avoid the need for supports completely with a little adjustment of the model to angle verticals, or design integral support structures into the model. You may also be surprised by the full capabilities of your printer, with most being able to bridge 50 mm gaps and print angles of 50º without any support at all.

Software solutions such as Cura and Simplify3D are capable of producing outstanding support structures, and for the most part these automatically generated supports will far exceed the quality of any home grown solution. But although auto-generated supports do the job, they can be difficult to remove. Applying your own support structures is a neater solution, but you’ll need to delve into the settings of your software to tailor the supports to your models.

Using Cura, click on the “Custom” options tab and then scroll down to “Supports”. By default you’ll have two options; “Enable Support” and “Support Placement”. Hover your mouse over the grey bar until you see the “Gear” and click, you’ll now see the Cura preferences; select “Support Pattern” and “Support Density” to start. There’s plenty of other options here that you can start to play with as you become familiar with the adjustments.

These settings will enable you to fine tune the support structure, and minimize the effect that the structures will have on the surface of your models. However, as careful as you are with the support settings, the supports themselves will be bonded to your model, so will always leave some sort of trace mark.

The issue of surface finish when supports are used is a big one and the severity of the effect will change depending on the material types you use. A more brittle filament such as PLA is often harder to work and finish than a decent ABS.

3D Printer Troubleshooting: Poor Surface Quality for Supported Models

3D Printing Troubleshooting Tip #1: Dual Extrusion

An expensive solution, but if the majority of your prints use complex support structures then a dual extrusion printer such as the Ultimaker 3 or the Cel RoboxDual is really the only way to go.

3D Printing Troubleshooting Tip #2: Check support placement

Cura and most software will enable you choose whether your support structure is just touching the build plate or everywhere. For most models select “Touching the Build Plate” to avoid cleaning areas of the model that really shouldn’t require supports.

3D Printing Troubleshooting Tip #3: Check the capability of the printer

Quite often people use supports without realising that their printer will quite happily bridge a gap or print at relatively steep angles. Most printers are capable of bridging gaps of 50 mm and printing angles of 50º without error. Create a test print and see what your printer is really capable of.

3D Printing Troubleshooting Tip #4: Adjust the support pattern

Depending on the model type, a change in the support pattern might be all it takes; try switching from “Grid” to “Zig Zag”.

3D Printing Troubleshooting Tip #5: Reduce Support Density

In your slicer software switch the view to “Layers” and take a look through the support structure. Default software will usually apply a dense support structure. If you reduce this density the support will become weaker, but as long as your printer is finely tuned this shouldn’t be an issue. In Cura a support density of 5 can be used successfully and vastly reduces the effect of the structure on the model’s surface.

3D Printing Troubleshooting Tip #6: Use the lower end of the filament temperature

Double check the filament temperature range and adjust the hot-end temperature to the minimum for the material. This may result in a weaker bond between the layers, but will also make it easier to remove the support structure.

3D Printing Problem Checklist: Poor Surface Quality for Supported Models

  • Dual Extrusion
  • Check support placement
  • Check the capability of the printer
  • Adjust the support pattern
  • Reduce Support Density
  • Use the lower end of the filament temperature

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What’s the 3D Printing Problem?

When you’re designing a product in your CAD application, the dimensions you’ve painstakingly planned need to be perfectly reproduced by your 3D Printer.

However when it comes to bolting your product together, you find that all that accurate measurement and design has gone to pot. Nothing aligns, all the holes are the wrong size, and nothing fits.

Print dimension accuracy is actually one of the few the areas of 3D printing where it’s highly likely that your printer is absolutely fine. Before you start checking the printer over, just double check that you have all your measurements correct.

Once you’ve checked the basics of measurements, then let’s take a closer look at the printer.

What’s Causing this 3D Printing Problem?

Let’s start with the measurements and the most common problem. First of all check that you’re working in real world measurements; cm and mm are probably best, although inches etc are fine if you must.

If all is fine with the unit selection, then double check the physical measurements of the parts. When it comes to measuring, always measure twice!

Now if you have separate prints that need to fit together, such as a male to female connector, or screw and hole, then make sure the insert is slightly smaller than the hole you’ve created for it.

For example if you have an M5 screw and you’ve created an 5mm diameter hole for it to go in, then it’s not going to fit (at least not without quite a bit of determination). OK this is obvious they’re both 5mm. In order to solve this, just increase the hole size by 0.1mm for a fine print and possibly 0.2mm for a low quality print. Print and try again. If it still doesn’t fit enlarge it a little more. If the hole looks oval then it’s not an issue with the hole measurement

If you’ve created a low polygon shape, then the likelihood is that your hole is no longer round and instead has slightly straightened edges. When printing an object with holes, always ensure you keep a moderate polygon count to keep those smooth round holes for things to fit in.

The same goes for custom shapes that need to fit together. Reducing the polygon count of one object can cause all sorts of issues if the two sections have rounded edges that need to interconnect.

Once you’ve finished checking everything with the models dimensions, it’s time to turn your attention to the printer. The first few layers are all important when it comes to print accuracy. Print out a test cube 50mm x 50mm and use digital calipers to check the measurements; make sure you print the cube at the same layer height you’ll be printing your final model. Firstly check the overall height to see if it equals 50mm, if it does then all is fine on the Z-axis. If not, then carefully measure the top 20 layers — these should equal 20mm. If this is correct but the overall height is wrong, then it’s likely that the first few layers are causing the issue.

To resolve this, check the height of the nozzle from the print platform and that it’s within the margin of error for your printer in relation to the layer height. If your nozzle height is 1mm from the print platform and your layer height is 2mm, you may find too much filament is being laid down in that first layer and causing the issue. If this is the case, either recalibrate your printer and ensure the nozzle to platform distance is increased or reduce the layer height.

Now check the X and Y dimensions. If they’re a good 1mm smaller than they should be but all proportions look correct, it could be due to filament thermal contraction. This is relatively common with ABS; in order to correct work out the percentage of error and increase the scale of the print to compensate. Using high quality filaments is the best way to avoid this.

Back to the hole and have a look inside; if the walls look smooth then everything is ok. If you see the layers protruding slightly then this could be a sign that the nozzle is too hot and the filament is oozing after it’s been laid down.

If the hole looks oval, then it could be that one of your belts is loose or there is a slight misalignment of the X and Y axis. Check all are tight and everything is clicked and screwed into place as it should be.

3D Printer Troubleshooting: Print Dimension Accuracy

3D Printing Troubleshooting Tip #1: Check dimensions

In your 3D printing application make sure you have the correct real world dimensions selected.

3D Printing Troubleshooting Tip #2: Double check the measurements

If you’re designing a part that needs to connect with other objects, double check your measurements and use a digital caliper.

3D Printing Troubleshooting Tip #3: Make sure parts fit

If you’re making a screw hole, create a virtual 3D M5 screw with a diameter slightly larger than it should be and use this to extract / create a boolean subtraction from the model you need the hole to appear in.

3D Printing Troubleshooting Tip #4: Keep polygon count high

Reducing the polygon count of your models can cause issues with the slightly flattened edges. Make sure you keep polygons within a reasonable count.

3D Printing Troubleshooting Tip #5: Print a test cube

Use a 3D Print Calibration Cube to check the X. Y and Z dimensions of your print.

3D Printing Troubleshooting Tip #6: Check nozzle temperature

If there are blobs on the inside of a hole then double check the nozzle temperature and reduce.

3D Printing Troubleshooting Tip #7: Check belts and rails

Check over the belt tension and make sure all axis are straight and correctly aligned.

3D Printing Problem Checklist: Print Dimension Accuracy

  • Check dimensions
  • Double check the measurements
  • Make sure parts fit
  • Keep polygon count high
  • Check nozzle temperature
  • Check belts and rails

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3D Printing Problems #21: Shifting Layers Shifting Layers

What’s the 3D Printing Problem?

The lower and top layers shift so that you get a stepping effect through the print. Usually it’s quite subtle, but these images shows a print with a more pronounced effect.

What’s Causing the 3D Printing Problem?

There’s a variety of reasons for shifting layers, and these can be as simple as someone knocking the printer during the print process! More involved shifting layer problems can be down to bent or misaligned rods, or even the nozzle catching on the print and causing a slight shift in position of the platform.

3D Printing Troubleshooting: Shifting Layers

3D Printing Troubleshooting Tip #1: Check that the printer is on a stable base

Place the printer on a stable base and in a location where it will avoid being knocked, pocked and generally fiddled with. Even a small nudge of the printer can shift the print base and cause issues.

3D Printing Troubleshooting Tip #2: Check the print base is secure

Most 3D printers use some form of detachable print base. Although this is handy when it comes to removing prints, and of course avoids damage to the printer, it also means that over time clips and screws can work loose. Make sure that when you reinstall the print platform it’s clipped or bolted tightly in place to avoid any slip or movement.

3D Printing Troubleshooting Tip #3: Watch out for warped upper layers

If you’re printing a high quality print upper layers can easily warp if cooled too quickly. As the layers warp they rise and can cause an obstruction to the nozzle as it moves, in most cases the print will release from the platform, but if it doesn’t the powerful stepper motors can push the print and platform around.  If your prints are suffering from warping in the upper layers try reducing the speed of the fans slightly.

3D Printing Troubleshooting Tip #4: Printing too fast for your machine

It is possible to speed up the print times for your machine by increasing temperature and flow. However whilst this may result in the filament flowing in the correct quality the rest of the machine may struggle to keep up. If you hear a clicking during printing this could  be a sign that the printer is going to fast. If you do hear a click the first port of call is to check that the filament isn’t slipping, before you take a look at the actual printer speed. To adjust your printers speed open up your slicer software and change the print speed.
In Simply 3D go to ‘Other > Default Printing Speed (mm/min)’
In Cura go to ‘Basic > Print Speed (mm/s)’

3D Printing Troubleshooting Tip #5: Check the belts

If layers are still shifting then it’s time to check the belts. A quick check is to just go around all belts and pinch the two together. The tension in each belt should be the same, if not then you’ll need to adjust the belt position to even out the belt tension. Over time the rubber belts will stretch (You can often tell if they do as they’ll start to slip on the drive pulleys), if there is quite a bit of play in the belts then it’s time to replace them with new ones. Over tight belts can also be an issue but this is usually only a problem if you’ve built the machine yourself. Some printers such as the Prusa i3 have belt tensioning screws that enable you to easily adjust the belt tensions.

3D Printing Troubleshooting Tip #6: Check the drive pulleys

These are the usually connected directly to a stepper motor or to one of the main rods that drives the print head. If you carefully rotate the pulley you’ll see a small grub screw. Hold onto the rod and taking hold of the attached belt and then tug the belt and try to force the pulley to turn. You should find that there is no slip between the pulley and stepper or rod, if there is tighten the grub screw and try again.

3D Printing Troubleshooting Tip #7: Check the rods are clean and give them some oil

Over time debris can build up on the rods which means that at some points along their length they cause more friction than others, which in turn can affect the free movement of the head and again cause layer shifting. A quick wipe and re-oil of the rods usually solves the issue.

3D Printing Troubleshooting Tip #8: Bent or misaligned rods

If you see the print head falter at certain points then it could be that one of the rods has become slightly bent. You can usually tell by switching off the machine so there’s no power going through the steppers and then move the print head through the X and Y axis. If you feel resistance then you know something is amiss. Start by seeing if the rods are aligned, if they are then remove the rods and roll them on a flat surface. If any are bent then it will be quite obvious.

3D Printing Problem Checklist: Shifting Layers

  • Check that the printer is on a stable base
  • Check the print base is secure
  • Watch out for warped upper layers
  • Printing too fast for your machine
  • Check the belts
  • Check the drive pulleys
  • Check the rods are clean and apply some oil
  • Bent or misaligned rods

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3D Printing Problems #22: Snapped filament Snapped filament

What’s the 3D Printing Problem?

The filament spool still looks full, and when you check there appears to be filament in the feed tube, but nothing’s coming out of the nozzle. This is more of an issue with Bowden feed printers than direct feed as the filament is hidden so breakages aren’t always immediately obvious.

What’s Causing the 3D Printing Problem?

Caused by a number of issues but primarily old or cheap filament. Although the majority of filaments such as PLA and ABS do last a long time, if they’re kept in the wrong conditions such as in direct sun light then they can become brittle. Then once fed into the printer no amount of adjustment is going to help.

Another issue is filament diameter, and this can vary through manufacturer and batch. Sometimes if the idler tensioner is too tight then some filament that still has a good amount of life left in it can snap under the pressure.

3D Printing Troubleshooting: Snapped Filament

3D Printing Troubleshooting Tip #1: Remove the filament

The first thing to do is to remove the filament from the printer in the usual way. In the case of the Ultimaker select Maintenance and Change Material. As the filament will usually have snapped inside the tube you’ll need to remove the tube from both the extruder and hotend. Then heat the nozzle and pull out the filament.

3D Printing Troubleshooting Tip #2: Try another filament

If after reloading the filament it happens again, use another filament to check to see if it’s not just the old brittle filament that should be disposed off.

3D Printing Troubleshooting Tip #3: Loosen the idler tension

If the new filament snaps check that the idler tensioner isn’t too tight by loosening all the way. As the print starts tighten until there is no slippage of the filament.

3D Printing Troubleshooting Tip #4: Check the nozzle

Check the nozzle isn’t blocked and give it a good clean.

3D Printing Troubleshooting Tip #5: Check flow rate and temperature

If the problem continues check that the hotend is getting hot and to the correct temperature. Also check that the flow rate of the filament is at 100% and not higher.

3D Printing Problem Checklist: Snapped Filament

  • Check the filament isn’t past its best
  • Check the filament diameter
  • Adjust the idler tension
  • Check that the hot end is clear and reaches the correct temperature
  • Set the flow rate to 100%

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3D Printing Problems #23: Stringing Stringing

What’s the 3D Printing Problem?

There are unsightly strings of plastic between parts of the model.

What’s Causing this 3D Printing Problem?

When the print head moves over an open area (otherwise known as travel move), some filament has dripped from the nozzle.

3D Printing Troubleshooting: Stringing

3D Printing Troubleshooting Tip #1: Enable Retraction

Retraction is an important factor when it comes to quality of finish and can be enabled through most slicing software. Its function is pretty simple and works by retracting the filament back into the nozzle before the head moves. The idea is that it avoids molten filament from trailing behind the head creating thin strings in its wake.

3D Printing Troubleshooting Tip #2: One click retraction activation

Most applications such as Cura offer a one click activation option, this uses a set of default parameters and for the most part is perfectly adequate. However, if you want a few more options there’s often a more settings buttons. Here you can adjust the minimum travel of the head before retraction is activated.

3D Printing Troubleshooting Tip #3: Minimum travel (mm)

Reducing the minimum travel is usually the quickest fix for stringing if the standard retraction isn’t doing the job. Drop the value in 0.5mm until stringing is stopped. Activating retraction will increase your print speeds.

3D Printing Troubleshooting Tip #4: Just cut them off

This isn’t the most elegant of solutions but simply taking a scalpel to the strings is quite often the quickest and easiest solution, and has the benefit that it doesn’t increase print times.

3D Printing Problem Checklist: Stringing

  • Enable retraction
  • Adjust the minimum travel before retracting starts
  • Just clean the print with a scalpel

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3D Printing Problems #24: Stripped filament Stripped filament

What’s the 3D Printing Problem?

Stripped or slipping filament can happen at any point of the print process, and with any filament. The result is that no filament is extruded from the hot end bringing your print to an abrupt end.

What’s Causing the 3D Printing Problem?

Blockage, loose idler tensioner, wrong hot end temperature, these are just a few of the common causes, but all are usually easy to correct. The result of the problem is that the knurled nut or toothed gear in the extruder is unable to pull or push the filament through the printer. As the motor spins the small teeth on the gear that would usually grip and feed the filament through the system, instead wear it away until there is no longer any grip, and the gear and filament slip.

3D Printing Troubleshooting: Stripped Filament

3D Printing Troubleshooting Tip #1: Help feed the system

If the filament has just started to slip, you can usually tell by the noise and the appearance of plastic shavings, then apply some gentle pressure to the filament to help it through the system. This will often help to get the machine printing smoothly again.

3D Printing Troubleshooting Tip #2: Adjust the Idler tension

Start by loosing the idler, feed in the filament and tighten until it stops slipping. Filaments vary in diameter so although the idler will absorb some difference in diameter some filaments will require fine adjustment.

3D Printing Troubleshooting Tip #3: Remove the filament

In most cases you’ll need to remove and replace the filament and then feed it back through the system. Once the filament has been removed cut the filament below the area that shows signs of slipping and then feed back into the system. If the filament has snapped it may be passed its usable best. Try it again and if it snaps again and you find the filament appears brittle discard and use another filament.

3D Printing Troubleshooting Tip #4: Check the Hot end temperature

If you have just inserted a new filament as the issue started, double check that you have the right temperature.

3D Printing Problem Checklist: Stripped Filament

  • Help feed the system
  • Adjust the idler tension
  • Remove the filament
  • Check the hot end temperature

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3D Printing Problems #25: Under-Extrusion 3D Printing Problem

What’s the 3D Printing 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 (see 3D Printing Problems #5: Missing Layers).

What’s Causing this 3D Printing Problem?

There are several possible causes. First, the diameter of the filament used does not match the diameter set in the slicing software. Secondly, the amount of material that is extruded is too low because of faulty slicer software settings. Alternatively, the flow of the material through the extruder is restricted by dirt in the nozzle.

3D Printing Troubleshooting: Under-Extrusion

3D Printing Troubleshooting Tip #1: Check the filament diameter

Start with the simplest issue, have you set the correct filament diameter in the slicing software. If you’re unsure about the diameter the value along with the recommended temperature is usually printed on the box.

3D Printing Troubleshooting Tip #2: Measure the filament

If you’re still not getting the results you want and filament flow is the issue, then use a set of calipers to double check the filament diameter. You should be able to tweak the filament diameter settings accurately in the slicer software settings.

3D Printing Troubleshooting Tip #3: Check the head

After printing, most printers will lift the printhead away from the print base. Quickly check that the nozzle is clear from a build up of filament and dirt.

3D Printing Troubleshooting Tip #4: Set the extrusion multiplier

If there is no mismatch between actual filament diameter and the software setting, then check the extrusion multiplier (or flow rate or flow compensation) setting may be too low. Each slicer application will handle this slightly differently but the principle is to increase the setting in steps of 5% and then restart the print process.

  • In Simplify3D open the Edit Process Settings dialog and go to the Extruder tab – the Extrusion multiplier setting of 1.0 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).

3D Printing Problem Checklist: Under-Extrusion

  • Check the filament diameter
  • Use calipers to measure the filament diameter
  • Check that the hot end is clear
  • Adjust the extrusion multiplier at 5% intervals

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3D Printing Problems #26: Warping 3D Printing Troubleshooting

What’s the 3D Printing 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 Causing this 3D Printing Problem?

Warping is common as it’s caused by a natural characteristic of the plastic. As the ABS or PLA filament cools it starts to contract very slightly; the problem of warping arises if the plastic is cooled too quickly.

3D Printing Troubleshooting: Warping

3D Printing Troubleshooting Tip #1: Use a heated print platform

The easiest solution is to use a heated print platform and to set the temperature to a point just below the plastics melting point. This is called the “glass transition temperature”. If you get that temperature right then the first layer will stay flat on the print platform. The print platform temperature is often set by the slicer software. You’ll normally find the recommended temperature for your filament printed on the side of the packaging or on the spool.

3D Printing Troubleshooting Tip #2: Apply glue

If you still find your print lifting at the edges then apply a tiny amount of stick glue evenly on the bed to increase adhesion.

3D Printing Troubleshooting Tip #3: Try a different platform type

Change your print bed to one that offers better adhesion. Manufacturers such as Lulzbot use a PEI (Polyetherimide) print surface that offers excellent adhesion without glue. XYZPrinting supply a textured tape in the box with some of their printers, basically a large sheet of masking tape, and again adding this works excellently, although only with nonheated print platforms. Zortrax 3D printers have a perforated print bed, models weld themselves to this surface eliminating the issue completely.

3D Printing Troubleshooting Tip #4: Level the Print platform

Print platform calibration can be another cause, run through the calibration process to check that the bed is level and nozzle height is correct.

3D Printing Troubleshooting Tip #5: Increase contact

Increasing the contact between the model and bed is an easy fix and most print software has the option to add rafts or platforms.

3D Printing Troubleshooting Tip #6: Adjust advanced temperature settings

If all else fails then you’ll need to take a look at your advanced print settings both on your printer and in your print software. Try increasing the print bed temperature by increments of 5 degrees.
In the slicer software take a look at the fan cooling, this is usually set so the cooling fans switch to full power at a height of around 0.5mm, try extending this to 0.75 to give the base layers a little more time to cool naturally.

Even if your printer has a heated print platform, it’s always recommended that you use glue and regularly calibrate the bed level.

3D Printing Problem Checklist: Warping

  • Use a heated print platform
  • Add Stick glue to the print platform
  • Swap from glass to an adhesive print bed
  • Calibrate print bed
  • Add platforms or rafts
  • Adjust advance the temperature and fan settings

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