The majority of people who own 3D printers will experience all sorts of issues with them. This can range anywhere from filament getting clogged to prints ending up looking like pasta. Most people who run into these issues will try to adjust their slicer settings (like retraction, extrusion, etc.) in hopes that this will fix the issue.

However, a lot of times it doesn’t and can’t. Simply put, the condition of your materials and the thermodynamic properties of your 3D printer parts have a huge influence on how successful your prints will be. Below, you’ll find the top 3 reasons why your 3D prints are failing, and what you can do about them:

Wet Filament

Whenever someone stumbles upon a stringy mess on their print, their immediate reaction is to increase retraction. While this can help, most of the time using dry filament will fix the issue immediately. Why does filament get wet and why does this help?

Well, a lot of filaments are hygroscopic, which means they retain moisture from their environment. If you live in a humid climate and leave your filament out all the time, your filament will end up getting wet. It is unavoidable.

Now, the reason this causes stringiness is that every time you go to print, you are heating up the filament with water trapped inside of it. When you go above 100°C, the water will boil out and pop (sometimes you can hear this). This popping disrupts the flow of plastic through your nozzle and ends up causing erratic extrusion behavior.

So, how do you prevent your filament from getting wet?

1) Buy a sealed container that you can store your filaments in. This will aid in keeping out moisture from your environment.

2) Place desiccant inside of this sealed container that can absorb moisture from the air surrounding the filament. While there are many different types of desiccant on the market, Slice Engineering's Filament Drying Desiccant seems to be the best one. This desiccant is 10X stronger than silica gel and is optimized for 3D printing applications.

Heat Creep

Simply put, heat creep is when heat travels up a hotend (which is the component on your 3D printer that is actually melting the plastic) and melts the filament too early.

In order to understand why this matters, the general anatomy of a 3D printer will need to be understood first (and is explained in the next paragraph). If you already know the parts of a 3D printer, feel free to skip the next 2 paragraphs.

To start, you have a roll of plastic, called filament, that you are putting into a component called the extruder. The extruder is responsible for providing the pushing force for the plastic filament as it makes its way towards the hotend.

Now, the hotend is made up of three main components: the hot block, the heat sink, and the heat break. The hot block is responsible for melting the plastic, the heat sink is responsible for keeping the plastic cool (and usually has a fan attached), and the heat break is responsible for separating the hot zone (on the hot block) from the cold zone (on the heat sink).

So, why is heat creep such an issue? Well, unlike most materials, plastics don’t have a clean transition from solid to liquid during melting. As filament moves through the hotend, it heats up and reaches the material’s glass transition temperature (Tg), entering a semi-solid, semi-liquid, “gooey” state.

While in this state, the plastic responds to applied forces like a wet noodle, causing undesirable print effects like reduction in resolution, blobbing, and jamming. This is where an efficient heat break comes into play. An efficient heat break narrows the physical distance during which the plastic is in this gooey-like state, ideally creating the shortest path from a cold zone to a hot zone.

With an inefficient heat break, you’ll end up having the heat cross over the heat break and into the heat sink which causes clogging, blobbing, and jamming.

Unfortunately, the majority of stock 3D printer heat breaks are made out of one material (since this is a lot cheaper). With this being said, this small component can have a drastic effect on your 3D printer performance and can end up ruining a lot of your prints if you don’t have an efficient one.

Our top recommendation for a replacement heat break would be the Copperhead® Heat Break. This bimetallic heat break is very affordable, will significantly increase the performance of your machine, and comes in multiple variants to fit printers from brands like Creality, MakerBot, and Prusa.

Aside from that, it will allow you to use engineering-grade plastics (like carbon fiber for drone frames & PETG for high-strength prototyping) that you didn’t even realize you had the option of using.

Inaccurate Temperature Sensing

This is an issue most people don’t even think about. At a base level, hotends on 3D printers heat up by having a heater cartridge pump heat into the hot block. The amount of heat that is pumped into the hot block is regulated by a temperature sensor on the hot block.

This closed-loop system is constantly monitored by the temperature sensor (just like the AC system in your house). If the temperature sensor reads the hot block is at a higher temperature than its set temperature, it will turn off the heater cartridge. If the temperature sensor reads the hot block is at a lower temperature than its set temperature, it will turn on the heater cartridge until the set temperature is reached.

Now, what if the temperature sensor is sensing the wrong temperature? In this case, your hot block will never ACTUALLY be at the temperature that you set since it is basing its feedback system on an inaccurate measurement. Being that filaments need a specific temperature to melt at, reading bad temperature measurements is a recipe for disaster. Luckily, there is a solution for this that doesn’t involve you finding a new temperature sensor. This solution exists in an inexpensive chemical called Boron Nitride Paste.

By applying Boron Nitride Paste into your sensor/heater holes and onto these components themselves, you’ll be getting rid of air gaps, increasing the amount of surface area these components are touching, and improving the conduction of heat throughout your hot block. Simply put, your temperature sensor will be reading the temperature the entire hot block is at since heat is being conducted through the hot block a lot more efficiently.