Why 3d print layers are not sticking – and 8 fixes

The prices for 3D printers have changed drastically and many people are now able to easily buy them, having 3D printers in their workshops. This has led many people to the ability to create whatever they can imagine; however many first-time printers quickly find that their prints are not turning out how they want.

3D printed layers won’t stick to each other when the heat is wrong, not enough filament is pushed through, or you are using the wrong filament for your design. Having a printing bed that is heated will significantly increase the quality of your printing and in many cases, it will help prevent layers from going missing or being too damaged.

Knowing what causes the problems does not always mean that you know how to fix them, with 3D printing many things can cause the same problem. Knowing what each solution is to all the problems will help you prevent bad prints and create some amazing prints that will amaze anyone who looks at them. Some of the weirdest printing mistakes can happen when just one slight mistake has been made during the planning stage of the print.

These are the things you need to know about 3D printing mistakes and how to fix them!

What can cause your layers not to stick properly?

As far as layers not sticking go many challenges can cause your prints to go into complete chaos. Some of the best printers were the ones that regularly experienced the challenge of not having perfect prints. It’s important to learn from your mistakes, which is why it’s important to have a few test prints before you start printing the largest thing you can.

These are the challenges that many people face when they start printing more complex designs, usually having not read the right instructions. If you find that your prints are not working properly you need to look at these things to have the print work properly.

Too hot or cold temperatures

This is usually the first thing that people use mistakenly, by setting the printer to be too hot or cold many printer owners assume that they are being safe with their new tool. Some of the most amazing prints are ruined by a filament that either did not stick properly to each layer or was so hot that the previous layer melted away from the nozzle.

The biggest mistake made by people with any filament is that they heat the filament too much, causing streaks, melts, and bends. However, when the filament is not heated to the right temperature it will be too cold, causing the layers not to stick to each other. Each of these has its challenges and when you do not have the temperatures right the nozzle can be clogged as well.

The reason so many people use the wrong temperatures is simple, the filament may be new or a different thickness, with many printers not always reading the instructions. Most filaments of each thickness and type will have a recommended temperature that you need to use them at. Reading what this is on the packaging or the seller’s website will help you in designing your prints.

Layering too fast

3D printing is a long process, something that many printers quickly learn is that even making a simple whistle can take up to 3 or 4 hours. This leads to the next big reason people find their prints not layering properly, usually ending up with prints that go out of shape as the print continues. When layering too fast there is a simple problem that occurs that can rarely be repeated.

When you are layering too fast the printer is moving to the next layer too fast, especially if the heat is too low or high. This causes the print to buckle under its weight, holes to form, or in most cases having rough layers that need to be sanded down significantly.

Layering too fast usually happens when people want to make their prints complete faster, telling the printer to move so fast that the filament does not have the chance to put the filament down. This causes the previous layer to not melt and accept the new layer, or the current layer that is being put down to become too thin.

Not enough filament

As a part of creating the design for your print, some 3D printers will allow you to change how much filament is being melted and put down. Sometimes designers will want to create thicker parts to some prints or have their designs have thinner parts that are almost see-through. This is when people start changing the amount of filament melted and pushed through.

Usually, this leads to the print having some spots that are too thick, however, not evenly, and other times there are thinner designs that won’t stick together. Some of the most frustrating things can happen when you are not pushing through enough filament, usually, something that causes hidden structural issues that are only seen when the print breaks down after the print is done.

Filament and nozzles all have their requirements and keeping these balanced is an important part of printing. It is vital to remember that a more expensive 3D printer will automatically know how fast to feed through the filament when you are using filaments that the manufacturer has licensed.

When using the wrong filaments

In the perfect world, all the filaments that you can use for your 3D printers will work with all the 3D printers in them. However, many owners quickly learn that bargain filament that they may find online or in shops are not at all the same as the name brand filaments. This is usually because the filament they have acquired is not the right mixture for what they are looking for.

Using filaments that require heating temperatures beyond your printer’s capabilities usually causes the layers to not stick together at all. When a filament has been created from the wrong material you may find that it can melt quite easily, however, the filament won’t stick to each new layer being made. Some of the most frustrating printing issues are the ones where the filament is not reacting properly.

It may seem odd but sticking to name brand filament usually allows you to rest easy, knowing that the printer will be programmed to know how to treat the filament. You can use a lower-cost filament, but you will have to use trial and error to find the right settings, usually leading to you wasting more filament than actually using them. However, some people like to use cheaper filament when they are testing odd designs before doing final prints.

How do you fix your layers not sticking properly?

While there are many common causes of 3D printing layers not working, many times it can feel impossible to know what is wrong just by looking at the final print. This is usually because you will be seeing many mistakes that are made for the first time when encountering a new problem. Some of the most frustrating feelings you can have are when a 5-hour print comes out and there are layered mistakes that seemingly only happened every few layers.

These are the most common things you can change and check on to fix your 3D printing, going from the easiest to change too much more extreme. You should consider doing these as you are testing and trying to figure out how the layering will work perfectly.

1. Adjust the printing temperature

This should be the first thing you are checking when your prints are turning out badly, many printers tend to rather go too hot than too cold. This is because a printer that is too cold can cause damage to the nozzle, which can take several hours and a lot of money to fix. This is why you will see that the default temperatures on filaments and printing machines are usually quite high.

If everything else in the machine is perfect then this temperature will also work like a dream. However, things are rarely perfect, and changing the temperature to be slightly lower or higher than the default will drastically change how your layers are made. Just be sure to first try the default and then change the temperatures around.

2. Change the fan and cooling speeds

An easy change that can be made without having to rely on too much guesswork is changing the speed of the fans that will be colling the machine and the print. The fans usually work to help control the temperature within the machine as it is printing, allowing some parts to be entirely cool to the touch by the time the nozzle goes back to it.

This is usually what you want, however, if you are printing smaller 3D objects you may find that the fans you have installed are not able to cool the layers as the nozzle moves around. Adjusting the fans to work a bit harder during these prints will easily allow you to have much cleaner and sleeker-looking 3D prints.

3. Increase the flow rate

One of the last things you can change that will not have too much of a knock-on effect on the rest of the printer is changing the flow rate. The filament is usually hanged in a large spool on the back of the printer or hooks near it. As the printer works there is a small motor that pulls through the filament as it is melted, much the same way as a regular glue gun.

However, this rate can be adjusted, with some nozzles requiring more filament to be pushed through than others. Adjusting the speed of the flow rate usually results in everything looking slightly better. It is important to remember that thinner filament will require faster flow rates or else the filament will become heated to a level uncontrolled by the printer.

4. Decreasing or increasing the printing speed

As you are adjusting everything else you could usually only give a cursory glance at everything else, however, once you start working on the printing speed you will need to slightly adjust everything else. Printing speed is how fast the nozzle moves to create each layer, which will affect the temperature, feed, and cooling that is happening in the printer.

Many printer owners are not aware that they need to change this speed to fit with the filament they are using, ending up with models that look slightly too layered for comfort.

5. Lower the layer height

One of the trickier things you can do is adjusting the layering height that the printer will do on each pass. Adjusting the layer height can solve issues of the previous layer melting too fast, or the next layer not sticking properly. However, because the filament thickness, melt point, speed of the nozzle and the cooling from the fans need to be considered it can be a challenge.

Most owners will never change the height of each new layer being made, sticking to the default layer height that is set out by the filament. When you do change this setting you should keep a close eye on the first few layers, as the nozzle may not go high enough to start the new layer. This can cause issues and challenges as the nozzle will become damaged and the prints will not look good.

6. Use an enclosure

A solution that sounds simple on paper but immensely complicated to implement right is the addition of an enclosure for the entire 3D printer. Most 3D printers on the market right now will have an enclosure already, however, some low-cost ones will not have one. Opting to spend the money on other parts of the system.

If you are experiencing that the nozzle is unable to reach the right temperature or that you must build a more robust cooling system, enclosures are usually the answer. This is owing to the enclosure creating a closed system that stops dust from getting onto your prints, but more importantly, allows programmed fans to cool down everything.

7. Realign the bed

The bed on which you are printing everything is one of the three most important parts of your 3D printer, it is also the most painful part of the printer to get perfect. Most nozzles can simply be removed, with the filament constantly being replaced, however, the bed may last the entire lifetime of the printer.

This is why you need to get it perfectly level when you first assemble the 3D printer, an uneven bed will cause newly applied layers to slope. These slopes cause the print to sag in the direction that the bed is uneven in, having the bed perfectly water level is the only way to have your prints not be lopsided for life.

8. New printing bed

When everything else seems to not work and your prints are constantly moving with the nozzle even when you know the temperatures and every other setting is perfect you will need to solve one last problem. The prints you are making need to be stuck to the bed you are printing on, many printers use different methods to achieve this, but there is only one tried and tested method that always works.

You may need to invest in fitting your 3D printer with a heated bed, this keeps the bottom layer of the model you are printing firmly stuck to the bed. This allows the rest of the print to stand stable and proper as the nozzle slowly completes the entire project. It should be noted that a heated bed has its own set of challenges but the versatility that it introduces should never be forgotten.

What are the characteristics of the two commonly used filaments?

Now that we know about all the things that can change how you are printing and what you should do to fix the challenges you may face there is only one thing left. The two types of filaments you can use should be remembered for their unique characteristics. Many cosplay lovers have learned to use PLA filament while more industrial designers prefer to use ABS filament.

These are the characteristics of each filament that you need to remember whenever you are choosing to stock up for your next project.

Conclusion

The layers of your 3D printing not working properly is not abnormal and many people quickly learn what they need to do to have the best possible prints. Even prints that may not look perfect can usually be sanded down to have perfectly smooth surfaces, many figure makers resort to acetone as well.

As long as the printer has enough filament and energy you may never have to adjust it, after the initial four months of getting everything just right!