the wait is over… 3D printer arrives

I can’t begin to tell you how excited I was to receive the shipping confirmation email. After nearly 5 weeks, my Prusa i3 MK3S finally shipped and was on its way to me. Needless to say, I tracked it like a hawk and refreshed the tracking page more times than I could ever possibly count. When it finally arrived, I quickly brought it in but sadly, due to other obligations, I simply didn’t have the time to immediately crack it open and get started assembling it.

Nevertheless, my excitement did not dissipate and with every passing day, my anticipation grew. At last, the day came when I could finally get started and the first thing I did was attempt to create a setup that would allow me to record the entire unboxing and assembly process from the top down. Unfortunately, I wasn’t able to do so with the things I had on hand. Despite having multiple tripods with lots of great features, I wasn’t able to rig up a mount that would allow for a clean, top down view of everything. So, I decided to scrap that idea and opted for a timelapse of the printer coming together. Doing so simply required ensuring the printer and camera were in the positions for each picture. I say simply, but as you can probably tell by the timelapse video below, I failed at doing so.

I knew assembling the printer was going to be a slow and tedious process because it is my first ever 3D printer, or any type of CNC machine. But, I did not realize just how tedious it was going to be and for precisely what reasons. For someone with chubby, short fingers and some issues with fine motor skills, the challenge of working with tiny M3 screws and bolts definitely in small, tight spaces proved to be frustrating at times. But the joy of assembling the printer with my hands and the anticipation of all the things I’ll be able to print when I was done quickly extinguished those flames of frustration. Before we get to enjoy that wonderful timelapse, let me take you on the days long journey of assembling my MK3S.

day 1

The first was what you would expect. Other than spending time trying to set up an overhead camera view, I took pictures of the unboxing. I was a bit surprised when I picked up the box to find that I could hear the metal parts moving about. I was slightly worried a part was damaged during transit but unboxing and examining the parts showed that everything was well packaged, even if the smaller boxes did move around a bit.

the box as it was shipped, but with the black plastic wrapping removed
view of the contents as they were packed (manuals and some bubble padding removed)

As you can see from the pictures above, the parts in the kit come in bunch of smaller boxes and within those boxes are many small ziplock bags, which have all been individually labeled with descriptions to aid in assembling the printer. This is actually very well thought out and very much appreciated. Along with the parts, the box contains a congratulatory letter (which also serves as a cheat sheet for screws and nuts), manuals for assembly and getting started, a printout showing the parts of your specific printer were tested and their results, and most important of all, a bag of Haribo gummy bears. In my research, I had read about the gummy bear part of the Prusa assembly, but now I am happy to say, I took part of the fun tradition with tremendous pleasure (gummies are one of my favorite, if not absolute favorite, candy). The kit even comes with a big bag of spare screws and nuts, just in case you lose them. These screws and nuts are pretty small and they do roll, so while I personally did not lose any, it’s easy to see how this bag of spare parts would come in handy for many customers.

Even though the kit comes with an assembly manual, it’s recommended that you use the online version just in case there’s something outdated in the manual that was included. You can also enjoy the benefit of reading comments from others who are going through the same process if you happen to get stuck on a step. Getting to the online manual is a breeze. Just use the supplied link on the congratulations letter or scan the many QR codes found on all the labels.

Once at the online manual, the fun begins. Equipping yourself with the necessary tools, you set forth on a staggering step by step journey that will undoubtedly consume hours of your time. While it seems daunting at first, the instructions are very well written and pair with pictures that make it difficult to make mistakes if you are paying attention and taking your time. As time ticked away and after spending (i.e., wasting) time trying to get a top view camera angle, I managed to finish the Y-Axis assembly, but not without some “problems.” I used quotes because what I thought was a problem wasn’t actually one.

At the completion of building the Y-axis, the manual instructs you to ensure that it sits flat on the surface. Having a flat surface to assemble the printer is very important and getting your Y-axis (and the primary frame of the printer) to sit flat will help contribute to high quality prints. Well, ensuring you have a flat surface to work on was my biggest problem. My frame rocked a tiny bit when I tested it. Although a small margin of imbalance (~2mm) is acceptable because the auto bed leveling would account for it, as a perfectionist, I refused to have it anything less than perfect.

For almost an hour, I tightened and loosened screws on one piece and then another. I pressed and pushed, while modifying how I was tightening the screws thinking that I was somehow doing it incorrectly and causing the frame to twist. Try as I might, the frame still rocked. I was ready to give up. I was ready to accept my fate of knowing that my 3D printer frame did not sit perfectly flat. Then, I rotated the frame and tried again. No rocking. I was ecstatic! I rotated it again and the rock returned. Testing my suspicions, I took the frame to my other table and tested it at various, rotated angles. No rocking. It turns out my dining table had imperfections in it that were the root of my “problem”. Thanks Ikea.

With the frame and Y-axis built, it was time to call it a night. The next day would be dedicated to getting the rest of the Y-axis assembly installed (belts, pullies, rods, etc) and the X-axis too, since it seemed to be pretty easy.

day 2

The second day of assembling arrived with more excitement and lofty goals were set. The tasks at hand were to install the steel rods along the Y-axis, bearings in the Y-axis platform, and the Y-axis belt assembly, which included the belt, belt holders, and pullies and bearings on either end of the frame. I also wanted to tackle the X-axis as well because it seemed relatively easy to do. Things started out pretty well. Installing the steel rods required nothing more than attaching the holders to the frame, snapping the rods in place, and securing them with zip ties.

one of the installed connectors with rod ziptied in place


Easy enough. The next steps to install the bearings on the Y-axis platform went without a hitch. Moving on, the Y-axis belt assembly seemed easy enough but proved to be difficult for me due to the tight spaces and screw placements. Even though I folded only a very small portion of belt ends to insert into the holders, the belt was already pretty tight when installing the holders under the Y-axis platform. As you can see in the picture below, the placement of the screws for the holders were located behind the belt. At this point, I hadn’t become aware of the long allen wrench with the ball head, so I was using the normal one. Having the long one in this instance probably would have saved me a lot of headache, but I managed to get it done, brushing aside hand cramps that popped up now and again.

the Y-axis belt holders beneath the platform

With the Y-axis portion of the build done, I enjoyed the brief moment of success with some gummy bears and moved on to the X-axis assembly. As I suspected, this portion of the build was relatively easy and merely required screwing together some pieces, installing the bearings, and inserting the metal rods. Easy peezy and it was done.

X-axis installed on the frame on the Z-axis rods

With the X-axis complete, that was it for day 2. It was time to get to bed and let the hand cramps heal. Tomorrow was a new day and what a day it would be because the goal will be to complete the most difficult part of the assembly: the extruder.

day 3

Knowing that today’s build would be difficult, I armed myself with a predose of gummy bears. I would need the sugar energy to push me through this assembly. Before I could tackle the extruder assembly, I needed to install the Z-axis. Much like the X-axis, this simply required a bunch of attaching parts to the frame and prepping the screw leads for the X-axis to ride on. As you would expect, this assembly was completely fairly quickly and with no issues. Then I turned to the extruder…

With the most delicate parts in the printer, it would be extremely critical that I get this part of the build correct. Not only did I need to ensure everything was aligned perfectly, but I also had to ensure that my cable management was done to perfection. The wiring on the hot end are very delicate and seem like they would snap off with a bad bump.

I took my time and everything was going smoothly. At least so I thought. When it came to screw in the cover for the optical sensor at the top of the assembly, I realize the square nut that was supposed to be aligned with the hole just wasn’t. I had somehow neglected to push the square nut all the way in! What a nightmare… Was I going to have to take apart everything to get that square nut back in? It was in step 1 of this chapter after all. But that was a problem for tomorrow…

day 4

The first thing I needed to do was figure out if I needed to disassemble everything I had so painstakingly spent screwing together the night before. Luckily, with some careful analysis of the manual, I concluded that all I needed to do was remove the back piece, which could easily be done after I removed the hot end fan. So, that’s what I did and successfully realigned the square nut. Not long after that, I was securing the optical sensor cover.

finally got it to fit!

Now, I could finally move on and connect the rest of the extruder assembly. I still had to attach the cooling fan, the P.I.N.D.A. probe, and attach the assembly to the X-axis bearings. Luckily, I didn’t run into any problems here and before long, it was on the X-axis. While running the X-axis belt, however, I ran into a slight problem. The tension on my belt was perfect, but for some reason, the belt twisted a bit going into the X-axis motor/pulley. I could not figure out why and thought that perhaps it was an imperfection in the printed part opening.

you can see how the belt on the right side slightly begins to twist

Despite chalking it up to an imperfection, it continued to bother me. So, I went back to the manual and read some comments for this particular step. Others had had the same issue! It turns out, I had placed the pulley gear in the incorrect orientation on the X-axis motor. Swapping this around fixed the problem and my X-axis belt was perfectly tensed and parallel to each other from the side and from above. Sadly, that’s where the fun ended on this day. But tomorrow (Saturday) brings an entire day of building!

day 5

Today was the day. The printer will be finished and I can start actually printing things! Things started out pretty smoothly. I quickly finished the extruder assembly and quickly moved onto installing the power supply and the control board. These were pretty straight forward and posed little problem at all. Then came the cable management, which I can definitely appreciate on any electronics setup. But for this, it was critical because you don’t want wires hanging in weird spots, getting tangled, or becoming disconnected and damaged. More than just pure aesthetics, cable management serves a highly functional purpose.


Thankfully, I didn’t have too many issues with this. My experience building PCs and other small electronics definitely helped here. I was able to get everything ziptied, bundled neatly, and connected to the control board and PSU as they should be. With that complete, my printer was fully assembled!

ready to print

Now that it’s finally assembled, I can start printing… or so I thought. There’s still a fairly long list of calibration and tuning to do before I can really start printing my designs and working on projects. But that process is a story for another post. Hopefully, it’ll be a short story with lots of good news and not one filled with tragedy and frustration. Stay tuned!

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