How to improve low-end FDM 3D printers

Until a few years ago, the only alternatives to start in the world of 3D printing were to acquire a commercial domestic printer, the cost of which was in many cases inaccessible, or to acquire the parts and components necessary to assemble a 3D printer from the RepRap project, either in kit form or separately. This last option was really affordable, but it required high knowledge and expertise in both assembly, programming and calibration to obtain good results. This was a significant barrier for many users whose goal was only to get started in the 3D printing process and not in the 3D printer building and calibration process.

Image 1: RepRap Mendel printer. Source: reprap.org

However, that has changed. Currently it is possible to purchase pre-assembled and pre-configured FDM 3D printers at really low prices. Brands such as Creality, Tevo, Anycubic, Artillery or Geeetech produce simple and ready-to-use printers with prices below € 500 and in some cases even below € 300.

A large part of this type of 3D printers are usually very low-quality equipment, with common failures and in many cases practically unusable, however, there are a few models that have achieved excellent value for money and monopolize good reviews in social networks.

Image 2 Ender 3 Printer. Source: creality3dofficial.com

Models like the Ender 3 and the CR-10s by Creality or the Sidewinder X1 by Artillery have become the gateway to the world of 3D printing for many users and although they may be ideal options to start, soon many users start to be aware of the limitations of this type of printers.

Cost savings and limitations.

Despite the good value for money of some of these 3D printers, it is inevitable that, in order to obtain such low prices, it is necessary to sacrifice the quality of certain components.

In general, the main weak points of these printers are the following:

• The quality and stability of the frame.
• The quality of the printing bases.
• The hotend.
• The extruder.

Some owners of this type of printer, who want to make the leap to more complex prints or more advanced materials, find that their 3D printer is not capable of reaching the right temperatures or that their extruder is unable to correctly pull a flexible material. In these cases, the question arises whether to make the leap to a higher quality printer, with the high investment involved, or to forgo using other types of materials and settle for the current quality.

Image 3: Original E3D and clone nozzle. Source: Hackaday.com

However, there is an intermediate solution: try to improve weaknesses and upgrade certain key printer components with high quality ones like those used in higher-end printers. In this way, the print quality can be substantially improved and the range of materials available can be expanded.

The quality and stability of the frame or structure

In general, the frames of these printers are usually light and in some cases not very robust. This is especially pronounced in the most economic ones, where in many cases the use of plastic structural components is abused.

Image 4: Geeetech i3. Source: geeetech.com

This implies that it is impossible to achieve high speeds and accelerations without causing vibrations that affect the print quality. Perhaps this is a less important weak point, since, knowing the speed limitation of each 3D printer and keeping the print speed below, the vibrations will be almost non-existent and the print quality good. It is also possible to improve the robustness of the 3D printer using printed parts or to improve stability by anchoring the 3D printer to a solid base that minimizes vibrations.

Print bed quality

Not always bigger means better. The higher the print volume on a printer, the more important it is to use high-quality components. Perhaps where this can be most clearly seen is in the printing dock. Currently many of these printers include a base made of a 2 or 3 mm thick aluminum sheet with a plastic sheet on its surface. While on a base less than 25 cm the flatness of the aluminum plate is usually quite good, on large-format 3D printers with bases of 40 cm or 50 cm the bases usually show poor flatness, especially in those with a thickness less than 4 or 5 mm. In this case, even if they are perfectly level, adherence problems or the impossibility of printing on the entire base usually appear.

The most advisable thing is to be realistic about the print size that we will need before purchasing a printer and opt for the smallest size that meets our needs. In most cases a 20 cm x 20 cm or 25 cm x 25 cm base is more than enough.

However, there are times when a large format printer is really necessary or we even find a small base that has poor flatness. In these situations the solution is quite simple and inexpensive. To improve a low quality base, you can buy a crystal the size of our base and place it directly on top of the base. The crystals usually have an almost perfect flatness, far superior to aluminum bases. In addition, to achieve the perfect base we can place an original or PEI Buildtak sheet on its surface that will ensure the best adherence of the pieces.

Image 5: BuildTak adherence base. Source: Buildtak.com

Another very interesting option to improve the printing bases up to 310 mm, is to install a high-quality magnetic base such as the BuildTak FlexPlate or the Ziflex base. These types of bases not only improve the flatness and adherence of the original base, but also facilitate the removal of printed parts.

Image 6: Ziflex flexible base. Source: Zimple3D.com

The Hotend

Most of these printers use low quality clones from branded hotends such as the E3D V6 and the E3D volcano. Although aesthetically they may seem the same, internally they have nothing to do. Unlike the original V6 hotends, these clone hotends are not all-metal, but the filament is driven through a low-quality PTFE tube. This, together with the fact that the cooling of the hotels is not in many cases ideal, implies that these printers are limited to printing materials with printing temperatures below 260 ºC. In addition, the probability of jams and Heat Creep is multiplied compared to a high-quality hotend.

Image 7: original V6 vs clone. Source: spiritdude.wordpress.com

Other printers like Creality use their own hotend, and although it is a good quality component, it is still a basic model limited to using materials with printing temperatures below 255 ºC.

Image 8: Original Creality Hotend. Source: creality.com

Updating a cheap printer's hotend may be one of the most important improvements that can be made, however, it can also be one of the most complex. When the serial hotend is a clone of one of recognized brands such as E3D or Slice Engineering, the best option is simple and consists of replacing it with its original equivalent. This not only implies the improvement of using a high-quality hotend, but also opens the door to having all the spare parts and accessories of each ecosystem, something of great importance in the long term if you want to advance in the world of 3D printing . In this case the only complication is the need to modify the printer firmware when the thermistor is replaced. It is important to know if the printer we want to update allows firmware modifications, otherwise it will be necessary to maintain the serial thermistor.

In cases where the hotend is self-designed, the process can be complicated. In the absence of a high-quality equivalent that allows for easy replacement, it may be necessary to redesign and produce new parts to accommodate an E3D or Slice Engineering hotend. This process can be very complicated for many users.

Image 9: Mosquito adaptation to an Ender 3. Source: thingiverse.com/brotherchris

However, this is simplified for those users of Creality 3D printers and other 3D printers using the same hotend, such as the Tevo Tornado, TronXY X5S, Alfawise U20 or Lotmaxx SC-10.

The American brand MicroSwiss has developed a high-quality all-metal hotend fully compatible with the Creality hotend. This hotend allows you to easily print filaments with temperatures up to 285 ºC, it consists of a grade 5 titanium heatbreak, a high-quality heatsink and a nickel-plated brass nozzle. In addition, it offers a wide range of compatible nozzles in multiple materials and diameters.

Image 10: MicroSwiss Hotend All Metal for Creality printers. Source: Microswiss.com

Extruder

Many of these printers use high quality extruder clones, however, as in the previous case, although the appearance is similar, the performance is much lower. Upgrading the extruder is probably the most important improvement, along with the hotend, and the one that can most affect the final print quality. On the other hand, in many cases it can be the most complex and the one that requires the most investment.

Here three situations can occur:

• Direct extruder printers
• Bowden extruder printers
• Bowden extruder printers converted to direct

Printers with direct extruder.

This case is similar to that of the hotends. If the printer has a clone from a recognized brand such as Titan Aero or Bondtech BMG, the best option is its original equivalent. However, in this case you have to be more careful and make sure there is compatibility. Unlike hotends, where in most cases the dimensions are the same as the original equivalent, extruders may have design differences that make direct replacement impossible. Most brands such as E3D or Bondtech provide plans and measurements of their extruders on their web pages, and it is also easy to find precise models of these extruders in the main 3D file repositories. It is recommended to measure the extruder of the 3D printer and compare it to the original one to make sure it can be easily replaced.

Image 11: Titan Aero clone. Source: Aliexpress.com

When the extruder has its own design, it will be necessary to adapt the printer carriage. Designs can be found in the main 3D file repositories to adapt quality extruders like the Titan Aero to the most common printers like some Creality ones. In the event that a new carriage needs to be designed, it may be a good option to replace the original extruder with the new E3D Hemera, its integrated T-Slot mounting system makes it easy to integrate into any printer.

Video 1: E3D Hemera mounting system. Source: e3d.com

In any case, changing the extruder in many cases implies modifying the steps per mm in the firmware, so we must make sure we can do it. In case of not being able to permanently modify the printer signature, the M92 command must be added in the printing gcode with the appropriate step configuration.

Bowden extruder printers.

This is probably the simplest case. Being fixed at one point, making a support adapted to a specific extruder is really easy. In this case, the best option is to replace the standard extruder with an original Bondtech BMG.

For most Creality and Tevo Tornado printer owners the process is even much easier. Bondtech has a version of its renowned BMG specially adapted for these printers.

Image 12: Bondtech extruder for Creality printers. Source: Bondtech.com

As in the previous case, it may be necessary to modify the configuration of steps per mm of the firmware.

In any case, whether the extruder is replaced or not, what should always be updated is the bowden tube. Replacing the standard PTFE tube with a Capricorn XS is a simple, inexpensive and much more important modification than you think. Having a bowden tube with a tight internal diameter and low friction greatly improves the precision and consistency of the extrusion. If we combine a Bondtech BMG extruder with a Capricorn XS bowden tube, we will get one of the best bowden systems that currently exist on the market.

Image 13: Current PTFE tube vs Capricorn XS. Source: Captubes.com

Bowden extruder printers converted to direct

In most cases it is the most complex option. In addition to the need to completely redesign the carriage to fit a direct extruder and modify the firmware to adapt the steps per mm, when modifying the position of the extruder it is necessary to extend the motor cable.

For those users of bowden printers, it is the best update possible, although it can be a very complex process, reserved only for the most experienced users.

However, as in the previous cases, users of Creality printers have several options to perform this conversion quickly and easily thanks to Bondtech and Microswiss. There are currently three direct extruders compatible with Creality printers:

MicroSwiss

MicroSwiss in addition to its Hotend All Metal for Creality printers, also offers a high-quality DDG extruder. It is a lightweight extruder made entirely of machined aluminum. It is compatible with the original Creality hotend, however the best option to get the most out of the printer is to combine it with the renowned MicroSwiss Hotend All Metal. The installation of this extruder is really simple and requires a few steps, in addition to being the cheapest option.

Image 14: MicroSwiss extruder for Creality. Source: Microswiss.com

Bondtech DDS

It is one of the most professional and complete options. It consists of a complete head consisting of a Bondtech BMG extruder and an original V6 hotend. Everything completely assembled and wired. This update allows you to have a direct extruder with some of the best components currently on the market, with the advantage of being able to install them easily and quickly. In addition, it allows the use of all the components of the V6 system, more complete than the Mk8 that comes standard. In this case it is also necessary to modify the steps per mm of the extruder motor in the firmware and the thermistor parámeters.

Image 15: DDS extruder for Creality printers. Source: bondtech.com

Bondtech DDX

It is the new direct extruder for Creality printers. It is the most versatile option of the three. Like the previous one, it is based on an adapted Bondtech DDX extruder, but in this case it does not incorporate the hotend, but is directly compatible with Creality's own. In addition, it allows the renowned Slice Mosquito and Copperhead hotends to be used through an adaptation kit. Combined with either of these two hotends, it is probably one of the most advanced direct extrusion systems out there today, on par with those found in many professional printers.

Image 16: Bondtech DDX extruder. Bondtech.com source

For many low-end printer users who want to make progress exploring new materials or improving the quality of their prints, updating certain components of their printer may be the best option without having to make the investment of acquiring a semi-professional or professional 3D printer. Simply updating the extruder and hotend assembly can improve the quality considerably as well as experiment with materials that were previously unfeasible or use new nozzles with diameters from 0.25 mm to 1.5 mm.

These options are especially interesting for those owners of Creality brand printers, since they have the widest range of options, as well as the best compatibility.