Review of the Pirx 3D Printer – A Great Value for Money Option
When we visited the Maker Faire in Hannover in June, there was a great many things to discover. As usual, we kept an eye out for anything related to 3D printing and in one of the two main halls we found a stand of a 3D printer manufacturer by the name of Pirx. We had never heard of these guys before and upon closer inspection we learned that Pirx is a Polish start-up who have brought their 1st 3D printer on the market only in January 2014.
The plywood framed machine is somewhat reminiscent of the Ultimaker Original and at first sight doesn’t stand out from many other 1st generation 3D printers. We left the Pirx stand having made a mental note about the competitively priced product but nothing much further. Back home, having exchanged a few tweets though, the guys from Pirx were eager for us to test their machine and happily provided us with a printer for testing.
We have tested the Pirx 3D printer over several weeks now and it turns out that it is a machine that definitely deserves a closer look. This review summarizes our findings, covering as usual both the good and the bad.
The Company Behind the Pirx 3D Printer
Pirx is a Krakow, Poland based start-up that develops and manufactures the Pirx 3D printers. Chances are that you have never heard of Pirx before and there is a good reason for that: not only have they been in market for less than a year but so far the company has been selling around 70% of its production within Poland. However, Pirx has been stepping up their expansion efforts during year by presenting their products at international shows such as the Maker Faire Hannover, the TCT Show + Personlize in Birmingham and the 3D Printshow in London.
The Pirx team has its eyes set on simple yet ambitious target: to build the most affordable and reliable 3D printer on the market. In order to do so, Piotr Lipert, CEO and Pirx co-founder, has assembled a diverse team that handles everything from mechanical design and software development to the electronics. All Pirx machines are fully designed and assembled in Krakow.
Pirx – Specifications
The Pirx sports a plywood frame, a non-heated acrylic build platform with a 3 point bed leveling system and a direct drive extruder. The printer works with 1.75mm filament and the hot end handles temperatures up to 250°C allowing it to print materials regular 3D printing materials such as PLA and ABS but also Nylon and other materials requiring higher extrusion temperatures.
A USB ports serves to connect the Pirx to your computer, there is no SD card slot or onboard controls that would allow the machine to print untethered. The 33 x 42 x 36 cm footprint makes for a medium sized build volume of 6000cm3.
At €599 ($800) plus shipping the Pirx is a very affordable 3D printer.
The complete spec of the Pirx 3D printer:
Unboxing & Setup
The Pirx was delivered in plain cardboard box. Upon opening it, I was hoping that the printer was undamaged since the box did not contain much in terms of padding to protect the printer. As it turns out, the machine was unscathed and I could proceed to setting it up straight away.
Other than the printer, the box contained the power supply, a USB cable, the filament holder and a spool of green filament. Anything missing? Well, at first I couldn’t locate any user manual until I remembered that this had been emailed to me previously.
As it turns out, Pirx’s default way of supplying the PDF user manual is via email. And while the PDF makes sense in view of the hyperlinks it contains, it would be nice if the Pirx came at least with a small notice pointing you to a URL where you can download the instruction manual. However, at the time of this writing, there is no such download link on the Pirx website.
The instruction manual is nicely illustrated though and walks you through the few steps required to get the Pirx up and running. Essentially you just need to remove all the zips that secured the machine during transportation, put into place the Teflon tube that holds the filament, install the software and filament, power up the machine, level the print bed and you are ready to go.
While working through these steps was easy, there were a couple of other issues: upon removing the filament spool from its wrapping, I noticed that it was covered in sawdust. As it turns out, the spool is made from plywood and that got a bit damaged during the shipping and plywood dust was all over the filament. As the Pirx user manual rightly points out, dirt is the enemy of your filament since dust will clog the extruder. I ended up having to clean the filament before installing the spool on the printer. Not a major issue but something that an overeager 3D printing beginner may miss and which can get him into clogging trouble.
The other issue I came up against was this:
The blue tape was all wavy and looked like it had been put on in a hurry without any regards to its effect on print quality. Not sure how this print bed passed quality control but I replaced the tape completely before starting the first print.
These two issues aside, the Pirx can be set up and running in less than an hour. When switching on the Pirx for the first time, I was pleasantly surprised that it lit up in blue. A strip of blue LEDs is placed against the front panel helping to illuminate the build platform and giving the printer a cool glow at night. Interestingly enough, this is not mentioned in the spec or elsewhere, hence the surprise on the first power up.
Host Software & Slicers
As per the Pirx manual, you need two pieces of software to run the printer: Repetier-Host as host software to drive the 3D printer and Kisslicer as slicing engine. The instruction manual shows you how to install both of these and I didn’t encounter any issues in doing so.
Pirx recommends Kisslicer as slicing engine mostly due to the degree of control that it gives you over the various settings. In practice, I ended up slicing most prints using the slicing engines embedded in Repetier-Host: Cura and Slic3r. Both slicers work fine, but for any 3D printing beginner I would recommend using Cura due to its simpler controls.
What about using Cura as host software directly? Cura being my host software and slicer of choice, I wanted to see if I could get it to work with the Pirx (despite the fact it is not explicitly mentioned in the Pirx user manual). As it turns out, Cura works with the Pirx but with some limitations. The direct printer controls (stopping the printing process, moving the print bed, homing the extruder etc) are not available in Cura. Thus, I could use Cura to slice the 3D models and start the print but always had to switch to Repetier-Host in case I needed to stop the print. A workable but somewhat unpractical setup.
Pirx did later confirm that there is only limited support for Cura, hence why they recommend Repetier Host and Kisslicer.
Pirx – 3D Printing Performance
To gauge the Pirx’s 3D printing performance, I decided to first put it through the same test protocol that was used at the 2015 Make 3D Printer Shootout. In fact, Make has made the testing methodology and models public such that anyone can use them to test their own 3D printers.
The Make testing is comprised of a series of 3D models that each test a very specific performance aspect of a 3D printer. All tests were run at a print speed of 40 mm/sec and at a layer resolution of 0.2 mm. The probes are then evaluated on a scale of 1 to 5 with 5 being the maximum score.
Here is how the Pirx performed on these models:
The dimensional accuracy probe measures how much backlash a printer produces. The probe consists of six super-imposed discs, each with a decreasing diameter. Once the print is completed, the diameter of the second disc from the bottom is measured. This has a target diameter of 20 mm, the Pirx’s probe showed deviations up to 0.3 mm. Score: 2/5.
The bridging performance test is designed to probe a 3D printer’s ability to surmount distances without support material. The probe has five distances to be bridged, ranging from 20 mm to 60 mm. The Pirx performed well on this test, it managed to bridge all the gaps with little to no filament dropping. Score: 4/5.
The overhang performance test simply measures the angle at which the printer starts struggling with completing overhangs. The probe has four angles at 30°, 45°, 60° and 70°. The Pirx managed the 30° and 45° angles very well, started struggling with the 60° though and drooping loops of filament appeared at the 70° angle. Score: 3/5.
Negative Space Tolerances
The negative space tolerance test is a measure of a printer’s ability to create fine negative (or empty) spaces making sure that two separate parts of a model don’t fuse together where they aren’t supposed to. The probe is a block with 5 pins, each with a decreasing negative space around it ranging from 0.6 mm to 0.2 mm. The number of pins that can be removed at the end of the print determines the score. The Pirx performed well, 4 out of the 5 pins could be removed. Score: 4/5.
Fine Positive Space Features Performance
The fine positive space features test essentially gauges a 3D printer’s retraction performance. The probe is a plate with 6 conical spires that thin out towards the top. This is the only test where the Pirx failed repeatedly: on the first try, the hot-end clogged up rapidly before the spires had reached a height of even 2mm. I tried various settings such as increasing the temperature to increase material flow but the best I could get out of the machine was a spire height of 6mm. Score: 1/5.
Mechanical Resonance Tests
Two of the test probes measure the mechanical reasonance in the XY gantry and the Z axis respectively. As resonance is difficult to measure quantitatively, this is a binary test which means that the test probes is either assigned a „pass“ or „fail“.
Mechanical Resonance in XY
The XY-resonance probe turned out fine: there is no noticable rippling at the corners nor at the inset of the print wall. Score: 2/pass.
Mechanical Resonance in Z
Though the Pirx managed to complete the Z-resonance probe, it did fail this test: taking a closer look at the corners of the finished print, it becomes clear that the edges are ridged along the entire height of the print. Score: 0/fail.
Articulated Makey Robot
The articulated Makey is an extremely challenging print that combines many elements of the above performance tests into a single probe. The articulated limbs have a gap of just over 0.3mm while the arms have overhangs of 65°, a challenging print for any 3D printer.
The robot produced by the Pirx turned out quite good: all limbs (feet, knees, shoulders, arms…) could be moved, proving that the printer managed the negatives spaces well. Only the head is firmly stuck on the shoulders and couldn’t be freed even when applying some force.
The surface of the robot’s body also came out fine overall though some smaller flaws could be detected upon closer inspection. The only area where that the printer visibly struggled with was the dome-shaped head of the robot. Here the Prix didn’t manage to close the curved surface on the last few layers of the print.
Curved head surface: Score: 2/5.
Body surface: Score: 3/5.
Of course, the testing of the Pirx did not stop at the Make probes. I tried a bunch of other prints to get a comprehensive picture of what the printer is capable of. Here is a selection of the results:
Some Other Observations
Pirx had delivered the printer with one spool of 1.75 mm, green PLA filament. Wanting to try a different color of filament, I replaced the green PLA with a spool of cherry colored PLA, a sample I still had from a Chinese manufacturer. However, that spool would not fit onto the Pirx spool holder. Not an issue when you have a 3D printer: I simply printed a new spool holder. In fact, I ended up using the 3D printed spool holder for all my subsequent prints since it turned out to be quieter than the original which was making a constant squeaking noise as the filament was unwinding.
Another modification I made to the Pirx was to replace the blue tape with a sheet of BuildTak. As the print bed of the Pirx cannot be removed, it quickly become tiresome to cover the build surface with a new layer of blue tape after every print. BuildTak is a semi-permanent, durable print surface and has the great advantage that it only needs replacing after every 100 hours or so of printing. So no more fiddeling with blue tape between prints, a considerable improvement to userfriendliness when it comes to the non-removeable print bed.
Support Put to the Test
I printed a lot of various 3D models with the Pirx. Overall, the machine performed fine and other than the occasional clogging and retraction issues I had no complaints until the day where I tried to change filament and I just couldn’t. It took me a moment to figure out why: as it turned out the stepper motor that drives the filament into the hot end had started running in reverse! Not only was this unexpected but also mysterious since I had not changed anything to the machine or its settings.
Time to put Support to the test! I emailed them with a description of the problem and had a first reply within 24 hours. They suggested to reverse the cables that driver the stepper motor on the electronics board but since I hadn’t touched those in the first place, it couldn’t have been at the origin of the problem. Asking them for an alternative fix they suggested re-installing the driver software. As it turns out, I had to leave for a week-long trip at the time. Upon my return, I decided to give it one more try before re-installing the software. Lo and behold, the stepper motor was running fine again and the Pirx printed like nothing ever happened.
Discussing the problem with Pirx afterwards, they said that only one similar incident has ever been reported. So, it seems that I stumbled across something rare, something that ended up being fixed (or fixing itself) but it happened, hence why I felt that it needed to be mentioned here.
- Print quality: the Pirx produces good print results, it performed well on most of the Make test probes but also on all other 3D models that I threw its way. The machine seems particularly able to handle negative spaces and bridging.
- Price: at €599 the Pirx is very competitively priced. And while the low price might suggest that it comes with a lower print quality that is simply not true for the Pirx. It is an affordable machine but also one that generates good prints. Looking purely at the price to print quality ratio, the Pirx is a serious challenger to some of its higher priced competitors. Another big plus for the Pirx is that it doesn’t rely on a proprietary filament system which means that it works with 1.75mm filament from any manufacturer. This translates into lower operating cost and opens up creative avenues when you want to be working with some of the more exotic filament types.
- Product quality: the Pirx is a quality product that has been well engineered, it has a very sturdy frame, a solid gantry, neatly arranged cabling and properly shielded electronics. Features such as the 3-point bed leveling or the LED lighting confirm that this machine has been carefully designed with the user in mind. During my tests I did not encounter any mechanical issues such as screws coming loose or belts that would have required re-tightening.
- Hackability: the plywood frame also opens up plenty of potential for hacking this machine. If you’d like to modify your Pirx by adding handles, additional lighting or even a heat chamber, the options to create upgrades and modifications abound.
- The total package: my biggest criticism of the Pirx has nothing to do with the machine itself, but rather with the total package that the machine represents. It is simply still a bit rough around the edges: the shipping container was a bit flimsy, the filament had to be cleaned before use and the blue tape on the print bad was installed in a sloppy way. It still also totally beats me why there isn’t a dedicated support section on the Pirx website or why the instruction manual cannot be downloaded from the homepage. Thankfully for the Pirx team, these things are easy enough to fix but they will need to be fixed if the company wants to establish itself as player that can compete with the big boys.
- Design shortcomings: when it comes to the design of the machine, the one thing that really bothers me is the non-removable print bed. Having to remove prints or replace blue tape while having to work with both hands inside the frame of the machine is not very comfortable nor very practical. Also removing a print that sticks really well can be a bit of a pain if you can’t remove the print bed from the printer.
- Noise and vibrations: the Pirx is a not a quiet machine. Once it is up to speed and printing away, it is loud and rough. Rough in the sense that it made my desk shake, especially when it was doing infills at high speed over short distances. Depending on the print, the vibrations were so strong and distracting that it was impossible to do any other work while the Pirx was running. When doing multi-hour 3D prints, you probably want to set up the Pirx in a separate room though that requires a dedicated computer since you cannot print untethered.
- Software options: granted, this may be somewhat based on personal preference but in order to make the Pirx truly beginner friendly it would be great if Cura was fully supported by Pirx. The software combination of Repetier-Host and Kisslicer is certainly manageable but not the most user friendly compared to the slick and clean user interface of Cura.
What is our final recommendation on the Pirx? Well, the machine is not perfect nor was the entire user experience completely flawless. However, the Pirx has price to print quality ratio that makes it a very interesting 3D printer.
At €599 you obviously have to do without some of the more advanced features such as onboard controls or an SD card slot for untethered printing. Any interested buyer should also be aware that the lack of a heated print bed limits the choice of materials that can be used in combination with the Pirx.
However, for anyone shopping on a budget, not having those features is a very acceptable trade-off. If you are looking to get into 3D printing without breaking the bank, the Pirx is a great option: the print quality combined with the open-source filament system and the affordable price are all very convincing arguments in favor of the Pirx!