Most home users who want to buy a 3D printer with a dual extruder want to print in multiple colors. That just sounds very interesting.
You are probably one of them. Correct?
The potential customer is not aware of some of the problems . Multicolor printing is imagined too simply.
Furthermore, the selection of devices is quite large. It is not (yet) as confusing as with single extruders, but the number of products is growing.
In this post I will go into the advantages and disadvantages of dual extrusion , give you a few ideas for a planned purchase and tell you which models are most suitable depending on your budget.
Dual means “containing two”. Such a 3 D printer thus contains 2 extruders (with 2 nozzles), through which 2 filaments can be processed in one print job without changing material.
Usually multi-material (e.g. object material and support material for overhangs) or multi-colored objects are printed.
There are kits , desktop devices and industrial 3D printers with which dual extrusion is possible. Some representatives are even all-in-one solutions.
Why are 2 extruders better than one?
- 2 different colors can be used without changing material,
- 2 different materials (e.g. for the production of composite materials or the use of support material such as bad / cheap or soluble filament in complex shapes) can be used without changing materials,
- 2 different nozzle diameters can be used for different object areas (to reduce the printing time),
- When using a material after the blockage of an extruder (initially) no cleaning / removal work is necessary and
- 2 identical (small) objects can be printed simultaneously as long as the distance between the nozzles is greater than their dimensions (“ditto printing”).
One could assume that the printing time is reduced (with the same nozzle diameters). Somehow that’s true.
Standard dual extruders do not print faster than devices with one extruder, because they share the same print head that has to be moved everywhere. Only the time for changing materials is eliminated.
For example, the Raise3D E2 from Raise3D offers two independently working extruders
The advantage of a blockage is of course deceptive. The 2nd extruder can also block … and it may happen more often than you think. (The support material PVA, for example, is not that easy to use.)
What are the disadvantages of dual extrusion?
- Less space is available on the print bed (ie the print volume is less) unless the frame is wider in the direction of movement of the print head than the corresponding size of the print area;
- there are fewer print models on the web;
- slicing is more complicated (each extruder must be assigned its model areas to be printed, ie separate model files);
- unequal material properties require a longer adjustment of the print settings (do both materials melt together or not ?; do both materials adhere to the print bed ?; keyword: material compatibility);
- 2 nozzles are more difficult to align in the Z-direction than one (keyword: nozzle spacing; a deeper nozzle can “scratch off” the material of the higher nozzle and if the distance to the print bed is too great, problems with the print bed adhesion can arise);
- Color contamination (oozing) can occur and
- the larger print head mass to be moved (especially with direct drive models) increases the chance of poor prints (accuracy) if no (slower) printing speed appropriate to the mass / acceleration is used.
In order to avoid oozing on the printed objects, e.g. Ooze Shields and Prime Towers are used. However, these increase the printing time.
With the most important points that speak for or against a purchase, besides the quality, your experience and your application goal (s) are.
Also pay attention to the existing support, which is particularly useful for beginners who are not afraid of additional difficulties. Problems are sure to be waiting for you – even if you are no longer a beginner.
FDM 3D printing in itself is a challenge for beginners . As you can read about the disadvantages of 2 extruders, you would have it “twice” as difficult with a dual extruder . So think twice about whether you really want to get one of these devices to start with.
If so, start by using just one of the two extruders and mastering all the basic processes with it.
If, on the other hand, you start with a single extruder, you can look out for options for a later conversion. For example, some DIY users convert their standard Prusa i3 clone to a dual extruder Prusa i3 variant. (With some other 3 D printers this also works.)
Here’s a little hack that allows you to print in multiple colors with a single extruder without changing materials. Maybe the finished object doesn’t look the way you imagine it, but still a nice idea …
You should always think carefully about what kind of objects you want to print and how often.
For example, if you need two-color printouts , and not only sporadically, but in the majority of cases , then you should consider purchasing it. Of course, the same applies to a model with many parts in different colors.
If you want to realize complex geometries and need, for example, soluble support structures , a purchase also makes sense. If, on the other hand, your planned print objects are very simple, a single extruder will surely be sufficient for your needs.
Even in the event that you need very detailed color prints, but want to paint the objects or otherwise post-process them with color (generally ask yourself whether painting would be better), you may still benefit from the use of soluble support structures.
If the production of an object takes a long time, a second spool of filament can also be useful.
Since dual extruders are more difficult to master than their single relatives, good manufacturer support would certainly be beneficial in the event of problems.
If not, stay relevant communities, such as forums or groups on social networks, to get help. The bigger and more active, the better.
Struggling to get through as a lone fighter can be frustrating (and time consuming). Tips and tricks on how you can set up your device correctly, on the other hand, bring you closer to your dream property.
If you’re a beginner in 3D printing, good sources of support are worth their weight in gold.
The quality of the device and the software affect the print quality . This may not be new to you.
As with standard FDM printers, the entire construction should be as rigid as possible. Vibrations are simply a hindrance to very good printing results.
Cheap China kits with acrylic frames, for example, do not deliver as good results as expensive prefabricated steel units (stiffer, heavier, …) without further improvements. To make it a little clearer.
But if you like tinkering or don’t want to spend that much money – why not. Whether it’s a popular Anet A8 that is retrofitted, or a ready-made dual extruder Anet A8 kit (under the name Anet A8-M ) – or any other option such as the Prusa i3 pro C from GEEETech – doesn’t make it that big Difference. A small advantage of the last 2 examples could be that they were designed for dual printing from the outset (e.g. larger frames).
There are of course other design elements that have an impact on the strength of the vibrations, such as the shafts or bearings.
(Printing parameters like printing speed also affect vibrations. The faster you print, the worse it gets.)
Pay attention to the extruder designs. How do you try to compensate for one or the other disadvantage mentioned above (alignment of the nozzles in Z-direction, color contamination, printhead mass, …)?
In contrast to the hardware, in addition to the paid Simplify3D, you can also use free slicers (e.g. Cura or Slic3r) with which you can achieve good multi-color printing results. You should avoid bad proprietary software.
As you can read in step 3 of the guide, use forums and blogs to ask for opinions on your preferred product. In addition, you should study reviews on Amazon or YouTube, which often provide deep, unadorned insights.
Unfortunately, there are hardly any real dual extruder tests , but if so, take a look at them.
Also note the described reliability!
Below are 7 recommendations that have been sorted by price.
This is one of the cheapest dual extruder kits currently available . The SD card comes with proper instructions and help.
In addition to the attractive price, the steel frame used also makes the device interesting. This increases the robustness of the machine. This reduces unwanted vibrations that have a negative effect on the quality of the printouts.
If you want an automatic calibration of the (heated) print bed, you will find it here.
Otherwise it is a typical Chinese open source clone, the already relatively good results of which can be optimized through adjustments (e.g. Cooling Fan).
The wiring of this dual extruder Prusa i3 and its protection (or the protection of the user) is also in need of improvement.
The Hands 2 from TENLOG is a Cartesian IDEX 3D printer kit .
If you want to do even more research, it is also worth studying the feedback from TENLOG – TL-D3 Pro or its rebrand HICTOP – D3 HERO . Hands 2 is just a smaller version.
Instructions are missing. (You could use videos from the larger TENLOG – TL-D3 Pro.) The assembly is still fairly easy and quick. Then it works almost immediately.
In terms of print volume, it offers just as much space as the popular Ender-3 , which is only a single extruder.
Two inductive limit switches are installed in each of the X and Z directions, mechanical representatives are installed in the Y direction, as is the case with most devices. Overall, however, the Hands 2 can work very precisely with it.
There is also a dual Z design and a linear guide in the X direction.
A touchscreen is available for operation.
The aluminum print bed can be heated. Nothing spectacular … Fortunately, the cable to the heating bed has a strain relief.
There is a very thick glass plate (6 mm) on the print bed that can be removed.
Calibration is not that easy now and can take a while – there is no automatic for it. The leveling wheels are large and easily accessible. After that, the effort is limited. So all too often there is no need to calibrate.
The frame is made of aluminum. For its size, the Hands 2 is quite difficult. But that is not really due to the two massive print heads with their direct drives. The whole construction is very solid.
Flexible materials such as TPU can be printed with the direct drive extruder without any major problems. However, 250 ° C nozzle or 80 ° C print bed temperature is not sufficient for all common materials. Nylon, for example, will be difficult to shape with it.
Out-of-the-box, the print quality is quite good. As with many other popular 3D printers, there is still potential that can be exploited with a little tuning / experimentation.
The long durability of the extruder connections was questioned by a user. But a replacement can certainly be found. (The possibility of replacing defective extruder cables is even easier.) In addition, the printheads are easy to replace, which is also helpful in the event of blockages.
Another user had problems with the motherboard.
The price is higher than normal for the space available, but it is pretty much the cheapest dual extruder (plus IDEX) with direct drive. There is hardly an alternative to this price on the Internet.
The Hands 2 is particularly suitable for those makers who want to produce flexible objects in multiple colors.
The QIDI TECH X-pro from QIDI TECHNOLOGY is a dual extruder of the old type.
The device is based on the open source design of the Replicator 2X from MakerBot .
The X-pro just has a few cool improvements …
Handles on the sides help to carry the relatively heavy device.
You have to assemble the desktop 3D printer a bit, for example attaching the print head, the filament guide tubes and the spool holders. A handy tool box (with content) is included in the scope of delivery. After about 30 minutes everything is done.
If you need help, a comprehensive manual is available. There are even video instructions on the USB stick.
Then you can start right away.
The device is quite loud after switching it on. This is due to a small fan in the lower part of the case that cools the mainboard. Experienced hobbyists could change it.
Rubber feet under each corner generally allow good ventilation of the hidden electronics. But they also reduce vibrations that can occur during work.
The device has a responsive touchscreen. German can be selected as the language in the menu.
The good thing about the X-pro is that a preview image of each model file is displayed on the screen. So you can find what you want to print faster.
It was criticized that certain entries first have to be deleted and then typed. A little awkward. It was also criticized that the electronics on the back of the touchscreen are exposed to the working heat from the interior during printing (no cover).
The print area (230 x 150 x 150mm) isn’t that huge now, but it should probably be enough for a lot of printing.
For this, the FDM printer has a closed installation space that (also) protects against ( children’s ) fingers that are too curious .
The whole construction is solid (or has proven itself, see Makerbot clone).
There is a plastic housing around the rather rigid metal frame. Print head and print bed move (Cartesian) on stainless steel. And there are no annoying cables.
The print bed – a flexible spring steel plate that is held in place by magnets – can be heated. There is a BuildTak-like surface on this, which unfortunately is very easily scratched. Fortunately, a replacement plate (even if you want to continue printing) is included. More can be found on the net.
It has to be calibrated manually.
The nozzle and print bed temperatures should be sufficient for all popular materials.
Due to the existing “housing” (acrylic door, acrylic hood and 2 acrylic side windows), easily warping materials such as ABS can be printed perfectly.
And the direct drive extruder can handle flexible filaments well. Even NinjaFlex (very flexible …) can be processed without any problems.
Compared to an Ender-3 Pro , the QIDI TECH X-pro seems to print a little faster (with the same settings) (see comparison video on the product page).
The print object is cooled from all angles by a turbo fan on the side of the dual extruder.
The print quality is (also because of this) good from the start (some users write “great”) and can be improved, as with (almost) all 3D printers. Multi-color or multi-material printing is of course more difficult (e.g. more frequent blockages).
Overall, the QIDI TECH X-pro does what it should.
It is possible to resume printing in the event of interruptions.
The printer from QIDI TECHNOLOGY can be operated with the pretty good manufacturer slicer QIDI Print or with any other slicer software, should unexpected problems occur.
A few points of criticism were loosening filament guide tubes, annoying beeps when reaching all limit switches and spool holders, which are not suitable for all reels. The latter can be remedied with your own, printed out bobbin holders.
If there are noises or vapors, you can let the device work in another room via a USB stick. A WLAN connection would also be possible.
In my opinion, QIDI TECHNOLOGY’s customer service is one of the best selling points. I hardly know any other manufacturer who has a similarly enthusiastic clientele. The company stands by its products and actually tries to help its customers quickly. The feedback (for example at Amazon.com or Amazon.de * ) shows this.
For all dual extrusion beginners who don’t want a kit and don’t want to spend thousands of euros, the desktop 3D printer is a great choice. In terms of price-performance ratio, it is certainly one of the best.
Easy. Cheap. High-quality.
Alternatives are the predecessor QIDI TECH II (alternatively often also referred to as I) or the Creator Pro from FlashForge .
The BIBO2 is fairly unknown in this country. Even more than the QIDI TECH II.
But if you read through the feedback from Amazon.com customers, for example, it becomes clear that this 3 D printer is pretty good and the customer service from Bibo 3D apparently much better (even “great” – you can also see in the comments that Bibo 3D there leaves that the company takes this very seriously) than that of many other manufacturers from China.
There are several variants of the product. With the version presented here, you could also use a laser engraver.
As with the previous device, the print volume is not really large. However, the BIBO2 lays the foundation for good printing results thanks to its closed installation space and robust design. It works reliably and is quite easy to use.
The Raise3D E2 is a plug and play IDEX device and is much more expensive than the previous products.
Even the commissioning is supported by videos that can be followed on the quite large touchscreen. Pretty much every beginner will probably feel that they are in good hands.
After the initial setup, you can start immediately.
German can be selected as the language.
The operation is user-friendly. The UI offers many options.
The desktop 3D printer looks high quality, even if you shouldn’t go for the outside … Inside, around the average print area of 330 x 240 x 240 mm, Raise3D has done an equally good design job. So for their first IDEX product.
The construction is stable.
The two print heads move in the X direction on a linear guide. The print bed moves along a dual Z axis.
The end stops are all optical.
The E2 should therefore work more precisely than many of its comparable competitors.
The print bed is held on the heating bed by magnets and can therefore be easily removed after the work is done. Likewise the print object, since the bed is flexible. Just bend and it “pops” from the BuildTak surface.
The calibration can be carried out automatically or semi-automatically (up to 64 fields).
For a device with a Cartesian drive system, the Raise3D E2 prints “normally” quickly.
Other nozzle diameters are optionally available, for example to increase the printing speed (print coarser) or the level of detail (print finer).
And the duplication and mirror modes increase productivity.
With a volume of 55-60 dB, the E2 is not one of the quietest 3D printers. If the noises are disturbing, you could let the printer work in another room (wirelessly) and monitor the printing progress remotely with the help of a built-in camera (via the RaiseCloud).
Thanks to the direct drive extruder principle, flexible materials pose few problems. The closed installation space, in turn, facilitates the processing of materials that tend to warp, such as ABS. In general, all standard filaments can be printed.
The in-house slicer called ideaMaker is found to be pretty good. An alternative would be Simplify3D.
The quality of the printouts is good right from the start and can get even better over time (experience, slicer settings). On the manufacturer’s website you can also find print settings for different materials , unfortunately not so many for this product.
The device generally works reliably. If one spool runs out, a filament sensor located in the print head reports. In the event of a power failure (or other malfunction), printing can resume automatically.
Printing will automatically pause when either the top lid or the front door is opened. (The fact that the door can open 180 degrees was also rated as super handy.) An integrated HEPA filter offers protection against harmful (e.g. ABS) odors.
In terms of security, the Raise3D E2 is therefore particularly suitable for schools, but can also be used in engineering offices.
Support for European customers is provided by their local dealers or resellers, which is now rated as negative if you have technical problems … The support seems okay for other inquiries. Additional help can be found in the Raise3D forum, for example.
Another small criticism concerned the side compartments for the coils. They are of course limited in size. If the rolls are too large, you would have to use external spool holders.
The CraftBot Flow IDEX from CraftUnique is part of the new “Flow” family. The 3D printers are similar to their predecessors, such as the Craftbot 3 or the very good CraftBot Plus , but are completely new designs. Because CraftUnique listens to its customers and also uses their brainpower / feedback.
This IDEX variant can be operated practically like a washing machine. (Likewise the other Flow family members.) After unpacking you remove the transport lock, connect the device to the power supply, install the equipment (i.e. the filament) and you can start.
It doesn’t even need to be connected to a computer. Data can be processed via cable or wirelessly with the help of a built-in Raspberry Pi (can be expanded).
Operation is via a touch display or the IoT web interface.
The Hungarian company CraftUnique is simply trying to achieve plug and play. The enclosed instructions can help with problems.
The print bed is heated. It should be pretty flat from the start, as there is a glass plate above the heating bed. This is then followed by further layers: a magnetic film, a (removable,) flexible spring steel plate and a bonded Kapton film (with good object adhesion). A finished object can be easily removed by bending the spring steel plate.
If calibration should be necessary, this can be carried out easily (with assistance) or automatically. A BLTouch sensor helps with this mesh bed leveling.
The hotend or the nozzle is longer than before. The larger heating zone enables faster printing. Further advantages are increased throughput, more play at the selected temperatures and fewer blockages.
The CraftBot Flow IDEX prints quite quickly. Officially it is a CoreXY system, but if you study pictures and videos it looks more like a Cartesian drive system.
Smaller / larger nozzles, with which you can further influence the printing speed (or the richness of detail), are included in the scope of delivery.
Mirror (printing 2 mirrored objects) and parallel mode (printing 2 identical objects) help to increase production much better.
The device works extremely quietly. The fans are the “loudest”.
The massive steel frame of the old CraftUnique printer has been reinforced even further. That makes the machine extremely heavy (there are handles on the sides, but 2 men would be better), but the construction is extremely stable / stiff. The linear guides have also become more robust. This reduces possible vibrations. And the accuracy improves.
With the possible nozzle and print bed temperatures, all common materials can be processed, including flexible filaments (through the direct drive extruder).
The cooling has been improved.
The print quality is good out-of-the-box. Even with two-color printing. This can certainly be improved through experience / better slicer settings.
The printer has plastic washers on the side. The door (can be locked via a sensor) and hood (with an integrated HEPA filter, e.g. good against harmful ABS odors) can be ordered as options. These enable a closed installation space with supposedly up to 80 ° C room temperature.
The 3D printer works reliably. Some even buy a print farm.
A 2-wheel mechanism ensures that the filament is fed in, and a filament sensor in the print head reports the end of a spool.
Hot-end clogging is rare. (The manual loading and unloading of filament should also lead to this. However, this problem can be avoided by using the display …)
In backup mode, printing would even continue with the 2nd printhead (and the same material provided) if all of the 1st coil or the nozzle of the 1st printhead should be clogged.
An integrated camera allows the work to be observed from a distance.
In the event of a power failure (or other interruption), printing can also automatically resume.
The manufacturer licer (CraftWare) is described as good. In theory, however, all common slicers can be used.
There are updates for the firmware from time to time.
Since the CraftBot Flow IDEX is a rather expensive 3D printer at over 3000 euros, it is more suitable for small companies that are just starting to 3D print, or for schools.
If the print area of 425 x 250 x 250 mm is not sufficient, the big brother ( CraftBot Flow IDEX XL ) could be an option. But then it gets even more expensive …
The processing quality is high. If the device should be damaged, the manufacturer offers each of its customers a guarantee of up to 5 years or 5000 operating hours.
The Pro2 is the successor of N2, with the Raise3D the 1st place in the make: 2018 Shootout reached.
The print volume is quite large for a dual extruder (305 x 305 x 300 mm). (For a “normal” FDM printer too, of course.) If the installation space is not sufficient, there is also the Raise3D Pro2 Plus (with 305 x 305 x 605 mm).
The device is therefore large. And pretty hard too; Inside there is a very stable aluminum frame. If the 3D printer has to be transported, it is best if 2 people are involved.
In contrast to the Pro2 Plus, which has wheels to make the machine easier to move, the Pro2 uses (only) rubber feet.
The X and Y axes of this Cartesian 3D printer work like the Ultimaker principle. So 2 waves cross each other and move the print head. The Z-axis is guided several times. One user described it as “outstanding”.
All limit switches are optical in nature. The wear and tear on these parts is therefore limited. And the work can be done very precisely (also due to the whole, massive construction).
Everything looks very high quality.
The inflexible aluminum print bed (with BuildTak surface) is magnetically mounted. After unpacking a test print (for pre-calibration) should be on it. Both the print bed and the heatable carrier plate underneath are thicker than on the predecessor.
The factory calibration of the print bed has been significantly improved. If a new leveling should become necessary (according to official information rather unlikely, also due to the stable guidance of the bed), the implementation (over 4 points on the underside) has been improved.
The setting of the nozzle spacing was also rated negatively for the N2. This is now done quite easily using an adjusting screw.
An automatic calibration is actually not required with the 3D printer.
The Pro2 prints faster than the N2. And different nozzle diameters can be used if you want to print even faster or more precisely.
The nozzle exchange takes longer than a (simple) filament change, since the hot end has to be removed and disassembled.
When he is working, you hardly hear the Pro2.
The device can print all popular materials.
The print results are good to very good out-of-the-box. (These can be further improved through experience / better slicer settings.) The surface quality was generally described as flawless.
In addition to the things already mentioned, such as the rigidity of the frame and the stable guidance of the axes, the object adhesion to the BuildTak film does not cause any problems.
Then the cooling on the print head is good. One fan cools the hot-end and 2 additional (controllable) fans cool the print object.
Furthermore, the direct drive extruder principle is used, which facilitates the printing of flexible filaments. There was even an upgrade (compared to the N2) to the Swedish manufacturer Bondtech.
In addition, there is a full enclosure that can be viewed 360 °, but it is not 100% airtight. (There are magnetically held, well-fitted doors and a hood that fits better than the previous model, also because it is heavier.) ABS can be processed excellently with this.
It gets very hot inside. Temperatures of up to 45 ° C were probably reached with N2. With the Pro2 Plus, the waste heat heats the installation space to 50-55 ° C.
This increases the success rate for warping materials.
(With the new high-quality 32-bit mainboard, the stepper motor drivers do not die away so quickly due to the high temperatures.)
And … The old rigid dual extruder has been redesigned. The unused nozzle is now automatically raised 1.5 mm via servo motors. As a result, it can no longer drag over the printed object.
The machine works reliably. A user once called the printer a workhorse.
A well-functioning HEPA filter was installed to protect against harmful odors (such as when printing ABS).
The in-house slicer ideaMaker is free of charge, intuitive to use and good (a “highlight” for a user). Raise3D provides regular updates for this.
Unfortunately the software is not yet in German. Alternatively, you can simply use other slicers (such as Simplify3D or Cura).
The user interface on the large, high-quality full color touch display allows quite intuitive, simple operation. Also in German! The screen is a little less bright than its predecessor, but all information is still easy to read.
The Pro2 does not have an SD card slot. Ethernet, USB and WLAN were retained.
An internal hard disk is available, for example, to store frequently used files on site.
On the display you can see the selected files with a preview image, which makes searching easier.
The transmission of the integrated camera can also be observed there. Or via the RaiseCloud; then for example via the app on the mobile phone.
A print can be paused if necessary. And should the device stop by itself, perhaps due to a power failure, there is an option to automatically resume printing.
Raise3D apparently responded strongly to the wishes of the N2 customers, which then led to the many improvements in the Pro2.
Even so, there are some negative things (old and new) that have been mentioned.
The old problem that spools that are too wide do not fit on the integrated spool holder, ie the side door cannot be closed completely, has not (yet) been resolved. There are 2 holes in the door for this purpose, in case you want to feed the material from the outside.
For the Pro2, however, the large coils are not quite as important as for the Pro2 Plus, with its much larger installation space.
Then something about the filament sensor, which is good in itself. But the optical detection used here does not work with transparent filaments. The light just goes through.
Furthermore, one of the users had a loose plug, which meant that a nozzle remained cool even though the correct temperature was shown on the display.
Another customer was having trouble getting online. His camera didn’t work either.
The customer service seems okay (see Raise3D E2).
The Pro2 has ultimately become a great plug and play commercial 3D printer. With an almost unbeatable price-performance ratio.
There are 3-D printers that can mix colors in addition to one- and two-color printing, as well as those that have more than 2 extruders. (Or you build some yourself.)
Mix-extruders used (e.g. E3D Cyclops Hot-End) are easier to calibrate, but have only one nozzle diameter, often limit the possible material combinations (since the temperature is the same for both materials) and are probably Bowden systems. In two-color printing mode, they also use more filament to protect against color contamination.
I would like to briefly introduce two candidates.
With multiple extruders it is currently not possible (at least I can’t think of an example) to mix 2 (or more) colors. For this you need special print heads that melt 2 filaments and then dispense the material at the same time via a nozzle.
The A20M from GEEETech is such an (open source) device, with which you can of course also print in one color. Two-color printing (no mix) is also possible.
The quasi-kit is relatively quick (30-60 minutes) and easy to assemble. The enclosed quick start guide is short, but you can work with it.
The workmanship is quite good. Nevertheless, it is recommended to check all screws, rollers and belts with this 3D printer (as well as all others from China), as it often happens that they are too loose / tightly tightened / tensioned.
The Mix-Color-Printer has a print area of 255 x 255 x 255 mm. That might be enough for many projects.
Mechanical limit switches are used on the A20M and there is only one threaded rod in the Z direction. The accuracy with which the device works is therefore rather average.
Cable management is good. There is a strain relief for the power supply on the 24V heating bed.
In an older video, a user stuck an enclosed BuildTak film onto the aluminum surface. Now a (removable) silicon carbide print bed seems to be included in the scope of delivery.
(In older videos the case is also open at the bottom. Not anymore.)
The bed calibration must be performed manually. An auto-level sensor upgrade is possible afterwards.
The aluminum construction is solid.
2 enclosed spool holders are attached to the upper end of this Cartesian printer and point diagonally upwards and backwards. Together with heavy coils, this construction is rather unfavorable. An increasing printing speed leads to (increased) vibrations, which have a negative effect on the print quality.
There are large rubber feet for this, which reduce the noise generated by vibrations (for example when standing on a table).
Most of the common plastics can be processed. With flexible filaments, the Bowden extruder is likely to cause problems and ABS and the like may not have a housing (you can build it yourself).
The quality of the objects is still quite good out-of-the-box.
Most often, so-called color bleeding occurred during mixing, ie the two colors were not printed properly separated from each other. This often has to do with the settings for the (rather too small) Prime Tower (which is printed to “clean” the nozzle). So it’s easy to change.
One user had cracks (in the object) when printing filaments at different printing temperatures.
All free slicers can be tried to optimize print results. Likewise Simplify3D etc.
The power resume feature allows printing to be resumed automatically if necessary.
Should there ever be a blockage (which can be assumed), cleaning the nozzle (or the hot end) is not that easy, as there are 2 inlets and one outlet.
A filament sensor is available. However, it must first be activated in the (Marlin) menu.
(You could also print twice as long with 2 identical rolls with a 50:50 mix.)
For one user, the plastic construction of this sensor broke after a short time.
The cheap extruders used (led to under-extrusion) and Bowden tube connectors were also criticized. There is still room for improvement.
The A20M simplifies two-color printing in its own way (one nozzle). And pretty cheap. Nevertheless, it (or a “dual extruder”) is not really suitable for beginners.
Various alternatives are listed on 3DDP , for example the A10M and the A30M , both also from GEEETech , or the CR-X from Creality 3D .
Are 3 not enough for you? 4 materials / colors are optionally possible with Mosaic’s Palette 2 * . For an Original Prusa i3 MK3S from Prusa Research there is a Multi Material 2S upgrade kit – MMU2S – with which up to 5 filaments can be printed at the same time.
If 2 extruders are not enough for you, you can keep an eye on the EI3-Tricolor from HE3D . There are already 3 colors or materials that can be used.
The whole part is quite similar to the well-known Tevo – Tarantula i3 , which however can “only” be upgraded to 2 extruders .
Really have not found any feedback on the product.
Alternative “mixers” would be the GEEETech – A10T , the GEEETech – A20T or the GEEETech – A30T.
Dual extrusion is not something for beginners and occasional users. For most people, single extruders are a good choice. They can also be used to print in multiple colors.
If at some point the desire for 2 extruders should arise, you can explore options for retrofitting. If that doesn’t work, you will find some recommended candidates here at 3DDP .
Depending on your budget and ability, satisfactory to very good print results can be achieved. Quality (actually) arises from good products and experience. But still check the manufacturer’s promise!
Write it in the comments!