John's Musings


Yeah, Me Neither

Original Prusa i3 Mk 2 - 3D Printer Review

I started 3D printing about a year or so ago with an inexpensive Prusa i3 3D kit from RepRapGuru. Wow the price went up some! It was like $280 and sold on Amazon and I remember seeing the same kit sold on eBay from the same person with a "Make An Offer". I think I offered $250 or something and they took it. Anyway the kit was pretty great and after using it a month or two I got upgrade-itis and rebuilt it with a new extruder and new lead screws, and added belt tensioners and good bearings for the belts to ride on. And I put overpriced Japanese bearings in it. It's really a great printer now but as with all things technology moves on. Prusa i3 kits now use PINDA probes for exacting nozzle positioning and mesh bed leveling which means even if your build surface is not perfectly flat or straight that the software (firmware) will compensate for it. This adds a huge quality increase, a speed increase if you are so inclined, and the printer in general prints about 31% larger objects. Of note there were a few things I wanted to print that wouldn't quite fit on the old printer.


Of note is the fact that my first kit was called a "Prusa"........that stands for Josef Prusa who now is in business and makes and sells the new Original Prusa i3 Mk2. Here's the best part. Make Magazine gave it the BEST OVERALL and BEST VALUE award for 2017. Think about that. Best printer at the best cost. You can read their review here. Also there is a guy named "Tom" on the internet that does the best YouTube videos for 3D printing there is. Don't mess with Tom. This video alone sold me.



Okay so Josef Prosa has his own company and makes the best printer at the best price. You can buy the kit for $700 or a fully assembled one for $900. I opted for the kit. And because it comes from overseas expect to pay $80 or so for shipping. Also there is such demand for the kits the lead time is 7 weeks!. While that sucks in this day and age of "I want it now" it speaks volumes for the kit in my opinion.


When the box showed up it was WAY smaller than I imagined. It is very well packed and very intelligently packed. The parts and hardware are in well labelled zip lock bags which correspond to the steps in the manual. I found no deficiencies in the packaging. Also they give you a bag full of spare hardware AND the tools to build the kit with. They literally thought of everything. I promise you the bag of spare hardware was added by someone who builds them for a living who drops screws and nuts behind the workbench. What an incredible touch. Spare hardware.


Electronics and motors and such are boxed wonderfully and safely as well. Parts that hook up to the electronics board that are similar and which could be potentially plugged into the wrong place are intelligently and distinctively marked in a couple of different manners. Really smart.


The build quality of the 3D printed construction parts in the Prusa i3 Mk2 kit is amazing.


When I built my first RepRap kit the build quality of the printed parts was "meh". I literally had to zip tie the X axis ends together so I could print new ones to rebuild it with. But such is the life of a 3D printer geek. Anyway the parts in the Prusa kit are perfectly printed. Another thing I enjoy about this kit is that although it is an advanced printing platform the end user building the kit doesn't have to dive deep into the extruder calibration. All that has already been figured out and preprogrammed. When I built my first RepRap kit I had to measure extrusion levels, do math, change values in the firmware to make sure the proper extrusion rate was happening. Not so with the Mk 2 kit. So while it a highly evolved Prusa i3 the end user just has to put it together.


It took me about 3 short sessions to build the kit but remember, I've built and then rebuilt a 3D printer before. I would guess it took me 5 hours or so to construct the whole thing. Basically as soon as it was built and I ran the first calibration it passed successfully and I was able to immediately start printing. The secret to that success is to ensure the Y axis frame is built perfectly and is square and the bed frame tracks perfectly. If the Y axis is built crooked you are doomed, doomed, doomed to have problems. Take the time and do it right and it will calibrate on the first go around.


Build quality of the kit is amazing. It is sturdy and the cable wraps make for a neat installation profile with great cable management. Here's a pic without the electronics and heated bed.



Now here is a pic of the completed, and working printer.



To make sure I was up to snuff I decided to print the dragon that is used in their promotional pictures and is shown on their web site. Kind of a rite of passage thing. Also the Dragon model (Adalinda, included on the SD card) takes about 7 hours and change to print and is pretty complex. I figure if my first print is a 7 hour complex model and it works then I can declare the build a success.


Nailed it!



Finally I gained another capability that I didn't easily possess on my RepRap kit. The ability to do 2 (or more) color prints. The picture below is also included on the supplied SD card.



Now, to make sure this wasn't some fluke I decided to try this on another model to make sure I could do this to anything I wanted to do it to. You have to modify the gcode to tell the printer when to stop. Prusa has added easy instructions and a gcode tool on their website to do this. The page even includes a great video that explains the process. Here's my stab at it.



As someone who has built a printer before and then rebuilt it and pushed it to the limits I can tell you that the Original Prusa i3 Mk2 kit raises the bar for 3D printers. The fact that it comes in an inexpensive kit form is like icing on the cake. They also have great software support and even have a customized version of Slic3r, the slicing software that generates the gcode used in printing.


Of note: Once I built my printer sure enough there was a firmware update and sure enough the firmware wouldn't load in Mac Sierra. And then equally sure enough on their support pages it seems there is a special firmware loader for Mac Sierra. Now it works great!. You can find a link to it on this forum page. Other than that there were only a couple steps where I scratched my head in the manual however the on-line assembly manual here has a place for builders to add comments which is ANOTHER STROKE OF GENIUS. All my head scratching questions were contained within the answers. Take the time to read the comments unless of course the directions are crystal clear, and most of the time they are.


Order one of these printers today. Best thing going. Thanks Josef Prusa!


And here I am in action and still using my first 3D printer as well. It's still viable just not as great as the Mk2.













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