3D prints fail occasionally, and it can be pretty frustrating when you can’t figure out what’s causing it. Sometimes, the prints fail at the same point, which can even be more bewildering. Figuring out what could be wrong can be time-consuming and sometimes even feel like an effort in futility.
3D prints may keep failing at the same point because the temperature falls, so the filament isn’t released, or because of an uneven bed. Additionally, the fan may be turning on at the same spot, so the filament clogs at the hot end. Also, check that there are no gaps in the top layer.
This article will look at the causes behind your 3D prints failing at the same point and the measures you can take to solve the problem.
1. Sudden Temperature Change
A sudden temperature change could cause the printer to fail at the same point. In some cases, the g-code, which contains the instructions for the print, may call for a lower print temperature.
When this happens, the nozzle will cool and cause the filament to clog the hot end.
However, not all filaments require the same level of heat. So, where the print may work with one color or material, you may find it stops with another due to temperature differences.
It’s also possible that the temperature was suddenly higher than before, causing the filament to drop too fast, such that it will start stringing at the same point.
How To Fix
Check the settings to see if the temperature change is responsible by printing the same model using a different material. If it finishes with a new filament, chances are you just need to make a couple of quick changes.
Use a temperature tower to test your filament and see where it works the best.
Check out this video to see a full explanation of how to use temperature towers:
If the nozzle is clogged, a sudden drop in temperature may have cooled the filament before it was extruded. If, however, the filament started stringing, the temperature at the extruder was too high. Therefore, you need to adjust the temperature settings so that it’s constant.
2. The Fan Suddenly Turns On or Off
Some 3D printers have multiple fans.
One fan blows on the tube before it reaches the hot end. This keeps the heat from getting to the filament and causes it to melt prematurely.
The other fan is located beyond the hot end. Its purpose is to cool and solidify the filament as soon as it’s extruded.
Some printers use a single fan for both functions. However, it’s easier to control the print process when operating with two fans.
If the printer has a fan that keeps the filament from melting before it gets to the hot end, should it stop suddenly, the heat might creep up, causing the filament to move faster and clog the nozzle. When this happens, the printer will stop releasing material at the same point.
If the fan at the hot end stops, the material won’t cool quickly. This may affect how the filament sets and dries, and the change may be evident in print.
How To Fix
Check the settings to ensure that the fan runs continually. Then, adjust the fan speed until you get the rate that works best for your prints.
Again, running test prints will be helpful here as you’ll be able to see how the fans affect the filament.
3. Uneven Bed
A leveled 3D printer bed is critical because it’ll affect the quality of your print.
Getting the bed perfectly flat may not be possible, but the more level it is, the better. If the bed is uneven, the nozzle will be too close to the bed in certain areas. This will cause warping of the print.
Some signs that the print bed isn’t level include:
- The filament fails to stick on the bed in specific areas.
- The nozzle fails to release filament at the same point.
- The print height is different even though the number of layers is the same.
- Differing gaps between the filament lines.
How To Fix
If your printer is automatic or semi-automatic, you should try and level the bed. However, sometimes, the automated systems don’t work as well as when you do it manually.
Check the point where the print is faulty so that you can focus on this area.
3D beds are usually held in place by adjustable screws, which you should be able to loosen to increase the distance between the nozzle and the bed.
Ideally, the nozzle should slightly touch the bed. If it’s too far, the filament released will form blobs. If it’s too close, the nozzle may not release the material at all.
Place a piece of paper on the bed while moving the nozzle back and forth. If the paper faces resistance because the nozzle is too close to the bed, loosen the screw to lower the print bed.
If the paper slips through easily, the nozzle is too high. You should tighten the screw to raise the bed slightly higher in the affected area.
4. Extruder Fails To Release Filament at the Starting Point
If your 3D printer fails to release filament every time you start a new print, then there may be a void in the nozzle where the filament is absent. This usually occurs when you are preheating the extruder and when it’s cooling after a print.
When you start printing, the filament is not extruded until the 3D printer has heated up sufficiently to initiate the consistent flow of material.
Another likely cause is the nozzle is too close to the print bed when you start printing. It doesn’t have sufficient space to release material, so it’ll only begin extruding when you move to the next layer after the print bed moves lower.
It’s also possible that filament clogged the nozzle while cooling.
This YouTube video will give clues behind your printer’s failure to extrude filament and possible solutions:
How To Fix
Here are the steps oh how to fix the clogged nozzle:
- Allow the printer to run for a few minutes to allow for the easy flow of filament.
- Use a needle to unclog the nozzle.
- Ensure the nozzle isn’t too close to the bed when you start printing.
The MIKA3D Printer Nozzle Cleaning Kit (available on Amazon.com) has multiple cleaning accessories, including tweezers and needles of different sizes. The needles are flexible, don’t break easily, and are compatible with various nozzles.
5. First Print Layer Fails To Stick to the Bed
One common problem in 3D printing is the 3D print fails to stick to the bed. This usually happens to the first layer, and it can be frustrating.
The first layer is essential because it forms the foundation of the other layers.
The print may fail to stick to the bed for various reasons, such as:
- The print bed is uneven.
- The extruder may be too far from the bed.
- The printer may be running too fast.
- Wrong temperature and cooling settings.
How To Fix
Here’s how to fix your 3D printer when the print fails to stick to the bed:
- If your printer bed is adjustable, loosen or tighten the screws or knobs to reposition the bed until it’s level.
- Ensure the nozzle isn’t too far from the bed. The filament starts cooling as soon as it leaves the hot end, and it starts to harden before it gets to the bed. If it gets too hard, it won’t stick.
- Use a slower speed to print the first layer to ensure the material bonds to the bed. Go to the settings and adjust the first layer speed. For example, if the rate is set at 50%, the first layer should be 50% slower than the other layers.
- Adjust the temperature and cooling settings. Filament tends to contract as it cools. If the first layer of your print appears to stick on the bed but separates when it cools, the temperature of the printer bed may be too low. You can also choose to adjust the fan speed to keep the filament from cooling too fast.
- Use an adhesive on the printer bed to help the material stick. Some 3D printers come with adhesives ideal for the print bed, while others don’t. Kapton tape seems to favor ABS, while blue painter’s tape works well with PLA. Other adhesives you can try include hair spray and a glue stick.
The Gizmo Dorks Kapton Tape (available on Amazon.com) is a superior adhesive for 3D printing. It’s resistant to high temperatures, prints stick to it readily, and it’s easy to detach the prints once you finish printing. In addition, one tape can go for multiple print cycles, and since a pack has ten sheets, you’ll print for a long time before you need to replace the adhesive.
6. Gaps in the Top Layer
Some 3D printers allow you to adjust the number of solid layers. This typically helps to save on filament that isn’t seen or needed for structure.
The top, bottom, and sides layers are often solid, while the inner layers are partially hollow.
Unfortunately, gaps in the top layer may appear despite the settings for a solid layer. If this happens to different prints, you need to check the cause.
Sometimes the gaps in the top layers may be caused by:
- The sunken solid layer fills the gaps in the lower layers.
- The solid layers aren’t enough to block the gaps.
- The infill percentage may be too low. If the infill percentage is only 10%, you’ll have huge pockets of air in your print. This is a poor foundation for the solid layers.
- The problem may be your nozzle isn’t extruding enough plastic to support the print. Sometimes the settings may be correct, but the nozzle isn’t releasing as much material as required. This is known as under extrusion.
How To Fix
Here’s how to fix gaps on the top layer:
- Ensure the software has the correct diameter of the filament you’re using. You can confirm the filament’s diameter using a pair of calipers. Most filaments have a diameter of 1.75 and 2.85 mm (0.07 and 0.11 inches).
- Alter the flow rate of the filament from the extruder. If the problem is under extrusion, changing the flow rate means more material will be coming from the nozzle. For example, if the flow rate was 1.0, and you change it to 1.08, it means the extruder is releasing 8% more material than it did previously.
- Print more solid layers. If the gaps keep appearing on the top layer of your print, you should consider increasing the number of solid layers. For example, if three solid layers don’t work, increase it to five to see if the problem will be solved.
- Increase the infill percentage. If you’re using 10%, increase it to 30% or 40%. The gaps will be smaller, hence providing more support to the solid layers.
7. G-Code Settings Pause the Print After Set Duration
The g-code (Geometric Code) is how users communicate with the machine, inputting commands so it knows what to do. Unfortunately, it’s easy to overlook some settings, especially if you’re new to 3D printing.
In general, once you have a 3D model, you’ll then import it to slicing software. That software will slice the design into layers and create a g-code file that the printer can read.
This is pretty advanced, so if you’re not familiar with g-code, you likely won’t be able to read it. However, it is possible that the g-code command may hold an instruction for the printer to pause after a set duration.
How To Fix
Check the g-code and pay close attention to the settings right before the printer fails. Hidden amongst the codes will be the problem. If you can read g-code, you should be able to make the necessary changes.
In addition, update all of the software, and try a new print to see if it works. Also, try a new slicer. They’re plentiful and free, so you can try again and see if the initial print will complete.
Failures in 3D printing aren’t unusual. Sadly, since one problem may have multiple possible causes, it takes time to find the culprit.
Fortunately, when you discover the problem, solving is usually a quick process. However, you need to be patient when troubleshooting the issues to ensure you get it right.