How To Tighten Ender 3 Belt Tension?

Do you want to know how to tighten Ender 3 belt and how tight they should be? If yes! Then continue reading this article as I’ve covered everything that you need to know about Ender 3 belt and their tension or tightness. 

I have covered everything from the disadvantages of loose belts to solid upgrades for your Ender 3 while covering the step-by-step process to tighten your Ender 3 belt and how to find the right tension for it and also some important things to keep in mind when adjusting the tension.

So, how tight should Ender 3 belts be? You want to tighten the belts to the point where there is no looseness or excess play in the belts. The belts should be as tight as they possibly can, without causing any stretching and physical damage to the belts. To get a better idea can continue reading the rest of the article.

Disadvantages of loose belt

The main disadvantage of having a loose belt on Ender 3 is a decrease in the quality of the print. Basically, when the belts are loose they won’t properly grip in the stepper motor gear, leading it to skipping gears. 

Skipping gears will lead the print to fail because either your print layers will start to shift or your print might have some visible layer lines depending on how loose your 3d printer belt is.

A picture showing layer shifting caused by loose belts in Ender 3

The above problems can be easily avoided by properly tensioning the belt on your 3d printer. So, now let’s look at how to perfectly tighten the belt on Ender 3.

How to tighten Ender 3 Belt

Since the belt for the y-axis comes pre-configured from the factory you will not need to tighten it because in my case they were perfectly tensioned and did not need to be tightened. For your Ender 3’s y belt, the factory settings should be fine 

How to tighten x belt on Ender 3

On the polar opposite of your x-axis motor, you will see your Ender 3’s x-axis idler. This is the part that is deciding the tension of your Ender 3’s x-axis belt. Changing the belt’s tension is very simple you just have to adjust and move the idler to the correct position

To follow along you will need only one tool and that is the second-largest Allen key that came with your printer and the largest Allen key which is optional(recommended).

To tighten the belt that moves along the x-axis on your Creality Ender 3 printer follow the steps below:

  1. So the first step is to loosen the two screws on the right side of the aluminum profile with the second-largest Allen key of your Ender 3 to the point where you can move the idler without applying much force. Don’t completely take them out or don’t lose them too much otherwise, you will need to do more hard work in setting it up again.
  2. Now you can easily adjust the tension of the belt by pulling the idler in the right direction. You have two options for this, either you can pull by hand or you can use the largest hex screwdriver that came with your printer. Pass the large hex screwdriver in between the idler and the aluminum profile and push the idler outwards to tighten the belt which I recommend or you can use your hands to pull the idler outwards to create tension on the belt.
  3. Pull the idler as much as you can, once you are sure you cannot pull it any further, or else the belt will break or stretch. Tighten the screws on the aluminum frame one by one while keeping the idler in the same spot.

Now check and make sure that the belt is not rubbing against the aluminum frame when moving the printhead and also check if the idler is parallel to the x-axis or not. If the belt is rubbing against an aluminum frame or it is not parallel to the x-axis then you need to loosen the screws again readjust the belt and tighten the screws again while making sure that these don’t happen again.

Now that you have tightened your printer’s x-axis belt, you will not have any of the problems that I have mentioned above. However, if you are still getting any of the above problems or your printer’s y-axis belt seems loose then follow the steps below to tighten the y-axis belt on your printer:

The process will be almost identical with one exception and that is the number of screws you have to tighten and loosen to adjust the tension of your Ender 3’s y-axis belt.

How to tighten y-axis belt on Ender 3

  1. Loosen the 2 screws on each side of your Ender 3’s y-axis aluminum frame so that the idler can move freely without too much force, just like you did for the x-axis.
  2. Pull back the idler as much as you can to tightly tension the belt for more accurate prints and hold it in place.
  3. While holding the idler in the same place tighten all the screws to keep the idler tight and secure.

Warning: Don’t pull the idler too much because this can damage your printer’s belt. If you put too much pressure on the belt, you will notice some peeling or stretch marks, which will cause the belt to break pretty soon.

-> personal exp: initial loose so bad print, lucky that start so fix and not fun

How tight should Ender 3 belts be

Many Ender 3 users get confused about how much should they tighten the belt and what is too tight or too loose for their printer. For the first time when I was tensioning my Ender 3’s belts I got confused how much tight they should be? How did I find out? By trial and error and at this point with my experience over the years I can get it right on the first try.

Now if you are doing it for the first time how can you find the perfect tensino? Well, the answer to this question is very simple, keep the belts as tight as possible without putting too much stress on them. Pull them to the point where you cannot pull them any further and stop at that point, if you go any further than that then the belt might snap and break causing damage to your printer and potentially hurting you.

Tight belts will prevent your Ender 3 from skipping gears which will result in precise movement of the printhead and in turn, you will get better prints with fewer layer lines. On the contrary, Extremely tight belts will lead to premature wear and tear of the belt and the stepper motor as well.

How to check tightness

This is not as complicated as many people make it sound I’ll explain you what I do for my 3d printer, the first step is to understand that you need to find it through trial and error and find the right tension that works for your prints and printer.

Now how do you check the tightness of your Ender 3’s belt? Well, what I like to do is pluck the belt to check the tension. Follow the steps below to replicate the test:

  1. Insert your finger under the belt, if you cannot insert the tip of your finger then the belt is too tight and you must release the tension a little bit by losing it. And if your whole finger goes under the belt then the belt is way too loose and will lead to inaccurate prints, in this case, you need to tighten it. The tip of your finger should go only a few millimeters under the belt and if that is the case then the belt is perfectly tensioned.
  2. Once the above test is clear, simply pluck the belt using your fingertip if it vibrates for a second or less tension is fine. If it doesn’t vibrate at all, loosen the tension by a little bit and if it keeps vibrating tighten the belt.

These two tests or steps are enough to find the right tension that your belt needs. Now I suggest testing practically by printing a calibration cube. If you see major layer lines or layer shifts then you need to readjust and tighten the belt and if your print looks fine then congrats you have perfectly tensioned the printer’s belt.


In this post, I gave you the personal method that I use to tighten and find the right tension for the Ender 3’s belt. It is very important to have the perfect tension for your Ender 3’s belt because belt tension affects both the print quality and life expectancy of the parts of your Ender 3. I always try to keep the process as simple as possible and I advise the same for you as well. Overcomplicating things doesn’t guarantee better results but sometimes it can even do the opposite.

If you still have any doubts or queries related to the process that you would like to ask you can always ask them in the comment box below.

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