Which 3D Printer Parts Are Most Likely to Break?

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Which 3D Printer Parts Are Most Likely to Break?

Because 3D printers are complex pieces of technology and are made up of an assortment of different working parts, it is worth taking the time to note which parts might be the most susceptible to breaking down and how much hassle and cost they may be to fix.

Please listen to my sad voice of experience! It’s much more efficient to spend an hour doing some maintenance rather than having your 24-hour print fail half-way through!

So, you see, anticipating which 3D printer parts are likely to break can save you a lot of hassle as you can plan for maintenance or replacements and plan fixes and replacements before you carry out important work.

It’s always a good idea to learn which components are the most fragile and why they are more prone to failing.  

This helps you not only avoid future failures, but it also makes it much easier to diagnose problems when your 3D printer fails, or your print doesn’t turn out exactly as you’d hoped.

Fortunately for you, as I’ve worked with 3D printers for nearly twenty years, I have a pretty good idea of which parts tend to fail, which I will share with you!

I use a variety of brands and models, from the Ender 3 to huge 3D Systems machines and everything in between, which makes it easy to spot common weaknesses across different brands and technologies.

What Makes Parts Fail?

The rule of thumb, as far as which parts are the most susceptible to breaking and the requiring repair or replacement, is that they tend to be directly correlated with being subjected to changes in temperature (i.e., parts that get repeatedly hot and cold) and components that are subjected to lots of motion and therefore friction.

Secondly, some parts on a 3D printer are inherently weaker because they are subjected to forces that cause them to fatigue. Often 3D printers are made to a low cost, which makes them cheaper for us to buy. The downside is manufacturers make certain parts as strong as they need to be and no more.

It helps to think about it in terms of which are the parts that are most likely to break if the whole printer were to be shipped and had to endure being bashed around in the back of a delivery van.


So, what looks like the most common culprit when a 3D printer stops working as it should? As it turns out, the PTFE tube that carries the filament into the hotend is the most commonly reported failure on FDM 3D printers.

If you think about my earlier points on what makes 3D printer parts break, the PTFE tubes are subjected to both heat and motion. They are made from a material that will definitely fail after being subjected to repeated heat cycles and back and forth motion.

There are all-metallic hotends available that do away with the PTFE tube. Although this completely prevents this kind of failure, I don’t recommend you change to an all-metal hotend solely for this reason.

PTFE is used because it is far lower friction than metal and prevents lots of clogging issues. All metal hotends are great for high-temperature filaments but are more prone to clogging.

The best thing you can do is schedule in replacing your PTFE tube. I recommend something like once every 500 hours of printing. Still, you should expect failure to be possible after 250 hours, so if you have an important print. It’s been more than 250 hours since you changed the PTFE tube, just go ahead and swap it out before risking your 30-hour Millennium Falcon!

It’s worth noting that one of the causes of the PTFE tube failing prematurely is excess heat, so if you find it’s often failing, check your nozzle temps are well below 250C.

Cooling Fans

Like on laptops, one of the most common things to break down on 3D printers is the cooling fans. The bottom line is that manufacturers often scrimp on the cooling fan as there are so many cheap versions available.

Just because your printer came from the manufacturer a certain way doesn’t mean that you can’t make your own improvements. When it comes to the cooling fans, there are several aftermarket upgrades you can buy. These will not only last longer than the stock versions but also offer you a performance advantage.

Another thing that you can do is to print your own fan cover, which will protect the blades, and direct the air to where it is needed most. You can also put small rubber pads to cushion the fan and like this considerably lower vibration noise.


One of the smallest and most fragile parts of a 3D printer is the little sensors that measure temperature called thermistors. They measure the temperature of key components such as the hotend and the heated bed and turn the heat on or off depending on whether the component is at the required operating temperature.

Thermistors are actually quite robust little parts as they have no moving parts. However, they are small and at risk of physical damage from being knocked or scraped when you’re removing a print.

As a general rule, the higher the temperature that the materials that you are using require, the more susceptible a transistor is to breaking.

Drive Belts

Many 3D printers use belts to move the X and Y-axis. These rubber belts are prone to breaking, especially if they have been fitted too tight or too loose. You should check the tension of your belts periodically and adjust if necessary to prevent damage.


Budget 3D printers often use cheaper bearings and sometimes even ship with bearings that shouldn’t have passed quality control checks at the factory. Fortunately, even good quality bearings of the type used in 3D printers are very cheap and easy to get hold of. Therefore, it’s a very good idea to check your bearings for any signs of wear and replace them as soon as possible. Worn bearings usually feel and sound rough when they move so it’s easy to tell if they need replacing.

Routine Checks

We are so used to mechanical machines working without thinking about it. 50 years ago, you wouldn’t travel anyway in a car without taking a pretty comprehensive tool kit with you! And of course, before any long journey, you would check the oil and water and maybe even gap your spark plugs!

3D printers are still early in their development. So when you’re using one, you should think like a pioneer of new technology rather than just pressing buttons on your microwave!  

If you treat your 3D printer well throughout its life, chances are that you’ll get a lot of use out of it.

3D printers go through a lot of abuse in the hours that they are printing. You can see the forces involved as your printer no doubt bounces back and forth with the rapidly accelerating and decelerating printhead. For multiple hours many parts are heated up to over 200C. Meanwhile, motors, bearings, and belts are all being pushed back and forth.

After a few weeks of printing, you should expect that some bolts may have worked themselves loose. A belt may have stretched a few millimeters. So, get checking and tightening where necessary!


Most 3D printers are built well and will print happily for years, but all that printing can take its toll. Make sure you check over your 3D printer regularly for loose bolts and any wear or damage. Following the guidelines in this article, make a maintenance schedule, and stick to it. A few dollars spent in preventative maintenance will save you much hassle and stress later and will ensure your investment performs at its peak for years and years.

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