One of the most popular 3D printers in the world also happens to be open source with the files available to replicate. Triangle Labs is a well-known manufacturer who produces many 3D printer parts and accessories, often based off of other products. They produce their own clone MK3S based off the genuine Prusa MK3S. Triangle Labs sent me their MK3S kit to build, test, and review. As a genuine Prusa MK3 owner, who has also reviewed the Fysetc MK3 clone, I was extremely curious to see how they all compared. Read on to find out!

The Kit

The Triangle Labs MK3S is a nearly complete kit which is available purchase on AliExpress. The kit does not include the Einsy control board. Consequently, this needs to be sourced from either Ultimachine who produces the Einsy for Prusa, or clones are also available for purchase on AliExpress. The kit did include 3D printed parts, tools, fasteners, and all the typical pieces that comes with the genuine Prusa MK3S. Costs for the parts, shipping, and Einsy board totals approximately $555 USD at the time of writing this article. It is available here.

Parts Included in AliExpress Listing:


1.Frame plate
3.Front&Rear Plate
4.MK52 heat bed PCB +1x Double sided Textured PEI Spring Steel Sheet (Upgrade on May 27,2019)
5.Aluminum profiles
6.Rod shaft and textile sleeve
7.Printed Parts
8.LM8UU bearings
9.DC fans
10.All Fasteners
11.Bon***ch drive gears & Springs
13.XYE stepper motor
14.Z stepper motor with nuts
16.V6 Hot end pre-assembled unit
17.PSU assembled
18.2GT Timing Belt +pulleys & idlers
20.Nylon Filament
21.Power cord
22.filament sensor for MK3S

They sent me an aluminum frame kit without the milled out PRUSA lettering. I believe this is a good choice to differentiate from a genuine Prusa kit and keep it from being an identical clone which could fool potential buyers in the future in thinking they are purchasing a genuine Prusa when the are in fact not.


I built this MK3S exactly as per the Prusa assembly instructions. All the parts were available, and nothing was missing from my kit. However, I had an issue which set me back a lot of time. I noticed after installing the Z Axis on step 4 something didn’t feel right. The entire X axis assembly was crooked. The right side of the assembly was lower then the left and wouldn’t straighten out without some force. This was going to be an issue during the calibration process so I put the assembly on hold to start troubleshooting.

I tried making adjustments to the z axis rod holders to see if they were angled, but that wasn’t the cure. The X axis rods were removed to see if they were the incorrect length, but they were fine. I checked to make sure the rods were seated appropriately in the printed parts, and that was also fine.

Finally, I checked the 3D printed parts themselves. I took them for granted and just assumed they’d be fine but in fact, they were the culprit. Something happened at the factory producing these parts that caused them to be printed crooked. I took some orange PETG I had used for the Fysetc MK3 parts I needed to print and printed the parts myself. This fixed the issue and the X axis was now level and moved freely. Side by Side you can see a gap forming showing the angle of the bad part on the right side. After replacing the printed parts on the X axis the assembly and calibration continued without any further major issues.


Moving on

As a results of my experience, I would highly suggest checking the 3D printed parts prior to assembly and I did inform Triangle Labs who said they would check their parts better and improve their QC process.

One additional minor annoyance is that the Z axis stepper motors both have the same long lead length as opposed to one short and one long that came on my Prusa and Fysetc machines. Therefore, extra slack had to be coiled and stored which Is not a huge deal but something I wish was better and more comparable to the original model.

I did notice that the belts that Triangle Labs provide, look very similar to the Gates belts that came on my Prusa. Also, they claim the bearings are Japanese, and all I can say is they were very smooth. Smoother than my Prusa and my Fysetc bearings.


First Impressions

My first print was a small Spring Bunny. The print came out really nice. It was sliced in Prusa Slicer with the stock MK3S settings. I was impressed like I was with the Fysetc MK3 but not surprised that it printed well out of the box as Triangle Labs has been known to produce good products.

I printed a some Pokemon for my nephew with the same good results, all with the same profile settings.


I wanted to continue printing and test the quality of the Energetic Spring steel plate and PEI. So, I went for a larger print that requires the tolerances to be considered since it’s an articulating part, the collapsible basket.

The print did not lift and it can collapse and open up without any issues. This was a great print printed with red Geeetech PLA.

I wanted to further test the adhesion qualities and print something fairly big by going with the screw sizer. It was printed with white PLA.

The below Battery Dispenser was printed in Marble PLA from Eryone and was my first part failure. It lifted in one corner causing a few layers to squish together and show an artifact. 

I wanted to try this printer with other materials. So I decided to print the parts for this heater block holder tool to help with nozzle removals. The body was printed with PETG sea green and the grips were printed in black CC Tree TPU. They were sliced in Prusa Slicer with the generic settings for those materials and the parts turned out great.

One other issue did come up during the printing process, and that was the Triangle Labs MK3S filament sensor. The sensor seems to have a small connectivity issue. When loading filament, the autoload function wouldn’t work properly unless I touched the filament sensor. Now I can’t pinpoint where this issue could have stemmed from: part QC, shipping, or assembly. This is their newest style MK3S sensor and it is my first time working with it vs the sensor that is used on the MK3. Consequently, I ended up disabling the filament sensor and didn’t have any issues but I plan to investigate further.

Community and Support

Much like how I mentioned in the Fysetc MK3 clone review, I am part of the Prusa Facebook group and if you show up with a Prusa clone looking for support your results and support may vary. There are some Prusa printer owners that are protective of Prusa as a brand and do not welcome a cloned alternative with open arms. I’ve seen this happen when people post asking about the clones. You also won’t be getting support from Prusa directly like you would a genuine product. Their support has been great for me personally with my genuine MK3 where required.


The Triangle Labs MK3S clone has printed really well. Is it worth the $250 USD in savings vs a genuine Prusa (with shipping)? That’s the big question I often get asked. There were the QC issues with the printed parts during assembly and I’ll make an assumption that will not be the case for everyone but I didn’t have that issue with my genuine Prusa. In my experience, Triangle labs has always been responsive with questions or concerns I’ve had with products I’ve ordered from them in the past. The printer does work quite well aside from the filament sensor issue which I need to dive into further, but even a replacement sensor is really inexpensive ($10) if that turns out to be the problem.

The prints are as good as the genuine MK3 and some of the parts they supplied felt like better quality then what I received from Fysetc. However, you will not get the same support from Prusa with the Triangle Labs MK3S which certainly has value when things go wrong, and they eventually do with most 3D printers. I for one think the Triangle Labs is a great option to keep in mind if you can troubleshoot and repair things without a lot of support and you want the same features as the famous Prusa brand.