CoreXY 3D Printer: Why It Makes a Difference

A CoreXY printer will have a square, cartesian design, which is different from a Prusa in that the print bed moves only on the vertical Z axis, while the print head moves on the horizontal X and Y axes. It is distinguished from the similar H-Bot printer because the much longer belt and pulley system used in a CoreXY system eliminates the excess torque that causes faster wearing in the belts and gantry.

CoreXY printers are typically cube-shaped, and on higher-end models will include an enclosure. The print head moves by employing two long timing belts, each of them connected to a stepper motor. Depending on which way each motor is spinning, the print head will move in different directions. An interesting quirk of the CoreXY design is that the print head will only move diagonally when a single stepper motor is activated.

Due to the design of the frames and the way in which the axes move, CoreXY printers have a number of advantages over other 3D printers, but at the same time, there are also some downsides. In the following article, we will be exploring both the good and the bad to determine whether CoreXY designs are really worth looking at, or if you should just stick with the more popular designs that are flooding the market.

One of the biggest advantages of CoreXY printers is that they can print faster without leaving behind artifacts in your print. This is because there are no moving parts of the significant mass.

With other printer designs, there’s typically a moving gantry that is attached to the stepper motors or the print bed. During a print, this gets hurled back and forth, which tends to cause excess vibration and results in artifacts.

On the other hand, the CoreXY design has all of the stepper motors fixed, and the print bed moves vertically. This means that the toolhead is the only part of the printer that is being moved at an appreciable speed with significant mass, and therefore a lot less vibration occurs.

What this means is that a CoreXY printer is capable of much higher print speeds, without as many print quality problems, such as ghosting and ringing.

Another advantage of having a bed that moves vertically, CoreXY printers are able to offer the same build volume while having smaller overall dimensions. This is a feature shared by certain designs like the H-bot.

On i3-style printers, the base needs to be around twice the size of the build volume so that the bed can move freely back and forth, allowing the tool head to access the entire build area. Typically, this results in a printer being longer than it is wide, making it difficult to efficiently place on some workbenches, and even harder to properly enclose.

With a CoreXY printer, the tool head moves horizontally in both the X and Y directions, allowing it to access to the entire build plate without needing extra space, making it much easier to enclose and place on shelves.

All in all, you might think that the CoreXY printer style may look bigger, but it actually has a smaller overall footprint compared to the i3 style and other FDM 3D printer designs.

So we’ve discussed two major advantages of a CoreXY printer. But let’s take some time to explore some of the downsides, and see whether they outweigh the advantages or not.

For starters, one of the biggest problems with a CoreXY printer is the belt system. While belts are essential to the functionality of the CoreXY design, they also cause problems if they are not aligned properly or if the tension is too high/too low.

When the belts are not properly aligned and parallel, they can create some major issues. The tension in the belts will potentially cause increased wear, could throw off the printer’s accuracy, and in some cases might cause certain malfunctions like bending printer components and negatively impacting the quality of prints.

The tension in the belts also plays an important role in the CoreXY design. If the belts are cheap, they can stretch and wear out, ultimately causing the printer to lose accuracy over time. As with any other FDM 3D printer, having the belt tension too high or too low can cause problems in part wear, accuracy, and overall print quality. Due to the increased length of the belts in a CoreXY 3D printer, these problems could end up being amplified and harder to repair, especially where wearing is concerned.

Another problem with the CoreXY system is caused by the design of the frame itself. Although the frame is quite stable in comparison with some i3 printers, the prints will lack dimensional accuracy if the frame assembly isn’t perfectly square. This issue can be solved by assembling the printer with a set square on hand, but it is more of a hassle than is experienced with i3 designs. Another consideration with CoreXY 3D printers is to add corner brackets to ensure that the frame stays square over time.

So, is having a CoreXY 3D printer design worth dealing with the aforementioned issues and higher price? We would wager that yes, it is.

Professional FDM 3D printers tend to follow the CoreXY 3D printer design, and there seems to be a good reason for that. It may cost more for one of these machines, but it’s hard to ignore the benefits of the design.

Building or even designing your own is always a possibility, and this has proven to be quite a popular option for some makers. Many people choose CoreXY over other designs because, at its core, it is actually more compact and easier to build. And, if the assembly is done correctly, the CoreXY design can provide even better print quality. The one trick is just to get the assembly and belt tension right.

So, if you’re thinking about buying a CoreXY 3D printer or building one from scratch, consider the pros and cons to figure out whether this design is right for your printing needs.