Original Prusa i3 MK3 guide for a new user


Hi, my name is Josef Prusa, I’m the creator of Prusa i3. In this first video in series of three I will showcase the new MK3. In this video I will help you with the first print of a freshly assembled printer. I hope you followed the manual, especially the chapter 9 “Preflight check”. First is the power up. You can use the toggle switch on the power supply. Then the printer greets you with the language selection So I’ll select English. This is the control knob. When you want to confirm something, you just press it. Down below is the reset button. If the printer is doing something weird or you are not sure that everything is going… …going right, you can just press it and the printer will immediately stop. I select English, but if you accidently select different language you don’t understand, you can just do the factory reset, which is mentioned in the handbook. Printer greets you with the Wizard which guides you through the setup process. If you accidentally hit No. You can always go to the Calibration menu… …and run it from there. The first part of the Wizard is the selftest which checks all the hardware parts of the printer. So we just run it from here. First thing the seftest checks are the print fan and nozzle cooling fan. Both are okay. Then it tries to heat up the hotend and monitors the temperature change if it heats up fast enough. The hotend is okay. And then the printer continues with checking the x-axis It goes back and forth and measures the length of the axis Now the same for the y-axis And now for the z-axis. This also checks the P.I.N.D.A probe. Everything is okay, and the printer continues with the bed heating. Again in heats up the bed and waits for the temperature to raise. This printer was perfect, but you may encounter some errors during the selftest. But you can find the resolutions for all of them in the handbook and also in the upcoming video… …about the errors. Next step is XYZ calibration, which measures the geometry of the printer. It will take roughly 12 minutes, so just confirm. First thing the printer will align the z-axis because if it’s at an angle we will just go all the way up. Until both sides hit the top, which will make it level. Be careful if you put these lead screw nuts the other way around, the z-axis may not reach all the way to the top. Then the printer asks you if you have the sheet on. I select yes and it asked me to remove it. It needs to be removed for the first part of the calibration. Next step is to check if the nozzle is clean. In my case it is clean, so I confirm. Get a piece of paper ready… …and during the calibration we will place the paper… between the nozzle and the heated bed… …and we will hold it all the time. If the printer or if the nozzle catches on the paper it is a sign that something is wrong and you should try readjusting the P.I.N.D.A probe and you can quickly abort the… …the calibration with the reset button. It’s still important to hold the piece of paper between the nozzle and the bed. Because if you… …if you remove it and walk away, that’s exactly the time when the nozzle will dig into the bed. Ok the second round of the… …skew calibration is done. And then printer asks you to place the steel sheet back. The sheet has two notches on the back and there are two pins on the back of the bed. So you can use this to align the bed (sheet) exactly on the on the bed. Perfect. Okay, we confirm. Now it does the full nine point Mesh bed leveling. The printer now stores the height of all the nine points on the bed and stores them in the memory. It does this before ever print, and if the values are different by large margin the printer knows something is wrong and ask you to check. For example if something was under the sheet. Okay, so the XYZ calibration is done, and we got perpendicular the best result. Let’s continue. Printer asks me if the filament is loaded and we select no and prepare the the filament. It is important to have a nice sharp tip and you can use pliers or side cutters to make it so. So the filament is not loaded. Now the nozzle will preheat, and then we will place the filament in the top of the extruder. In the meantime it is very important to place the spool on the printer this way so the filament goes from the top to the front. If you do it other way the filament might require too much force to… …unspool from the spool. Okay. Printer asked me to insert the PLA into the top of the extruder and confirm. Now it’s loading the filament. You can watch until the filament will start to go from the nozzle. Okay the filament is loaded and you can remove it. Be careful not to touch the nozzle, it has 200 degrees Celsius which will burn you. Next step is the first layer calibration, where we will set the distance between the nozzle and the steel sheet. Before we do so we need to clean the bed. We ship the printer with alcohol prep pads, which is isopropyl alcohol, so you just open one and… … wipe the bed with it. Be careful not to touch the nozzle. Good. Now back to the printer. We will start the first layer calibration. It is really important that the steel sheet is on the bed. You cannot print without it. The printer jumps into the main menu and starts preheating everything. It does the Mesh bed leveling, all the nine points. Then it prints the intro line to stabilize the pressure in the nozzle. And you can see the new menu on the LCD. Adjusting Z. So you will scroll down… …until you see that the line is nice and stuck to the bed. The value will be somewhere around minus one millimeter. We just watch the the line and adjust it until it’s nice and squished. You can see the picture how it should look in the handbook. I’m pretty well set up, my value is minus 1.15, but it will differ for every printer. When the meander finished, you can see that it will start to print a small square piece where you can check the distance is properly set. You need to let the printer finish this file completely. Because otherwise the value will not be stored in the memory. Before you run it again, you need to remove all the stuff from the bed which should be very easy to do with just your bare hands. And now we need to clean the bed again. To clean the bed best is to get the isopropyl alcohol. That is for everyday cleaning before ever print at least 90 percent or more. In case you cannot get isopropyl alcohol. You can use Windex, which isn’t as good, but will also work. And you should also get some acetone, which you should use at least once a week or when the prints stop sticking. It rejuvenates the surface of the bed. We don’t want to run the first layer calibration again, so we just click no. Okay, so the wizard is done and printer wishes you happy printing. Now we are ready for the first print. First we will need to clean the bed again, so I’ll just get tissue and some isopropyl alcohol. And gently wipe the bed. Good. First we will preheat the printer. So just go to the menu, select preheat and select PLA. When you are testing your first print it’s very important to run the g-codes from the SD card because they are tested. So now we will start the print from SD card which is placed here. So just go to the menu and select print from SD. And the first print we will do is… MK3_PLA_Prusa, which prints a small badge with the Prusa. As the printer was preheated it should start printing immediately. Again the printer does the mesh bed leveling first. Then it starts with the intro line and moves to the print. If you feel that the first layer is not stuck enough or if it’s too low you can go to the menu and… …call Live adjust Z where you can set or readjust the distance between the nozzle and the sheet. Now I will tell you something about slicing. If this is your first printer. I strongly suggest to use the Prusa Control. It is part of our drivers package, which also includes the sample objects. It is pretty simple you just drag and drop one of the objects into the main window of the Prusa Control. You select the material print quality and infill. Then you just hit generate and wait. When the generation is complete you just save the gcode on to SD card and put the SD card into the printer Now the print just finished, and I’ll show you how to take it off. Now you just clean the bed, and you are ready for another print. Congratulations to your first printed part. In the next video I’ll show you how to resolve the errors you might encounter during the setup process. Thank you and happy printing.

65 thoughts on “Original Prusa i3 MK3 guide for a new user

  1. I only hear good things about your printer and I would get one immediately… however, the print size is too small for me. If at least the Z axis would be bigger, that would help. The question is, why is it not "taller"? I mean, manufacturing wise there is no way it would make the printer that much more expensive, right? That said, I hope you come up with a "taller" print area soon!

  2. Hello, can I print my new prototype Polish Combination Lock on Prusa MK3? Can somebody download STL from my page and test it? I like to buy this printer but I am not sure if it is good enough. Please help me to check this. Thanks.

  3. I love that this is available as a kit or pre-build at different/affordable price points. REALLY AWESOME. open source; great for developers. OUTSTANDING!

  4. Hi Josef, this Video marks the end of an excellent Documentation! I finished the Build of the Mk3s 2hs ago. No problems, everything worked from the beginning. Thanks a lot!

  5. when printing really tiny but precise parts like little furs on the owls my printer shakes. is this normal? I have a filament holder on the side and it shakes a lot! my prints come out fine! it just shakes a ton whent he head is rapidly moving left and right!

  6. i own a Prusa Is3 Mk,3,,probebly produced Monday morning, no adhesion at all, I love the chez people. LOL. 800 bucks wasted, back to 3Dlac.

  7. Is the i3 MK3 ready to print high temp filaments or does it need to be upgraded to all metal hot end? Thank you

  8. Something wrong with the original extruder motor plate it pushes the steel ball therefore sending a signal that the filament is present when there's no filament. Brand new order. Help please

  9. For those eager to start with PETG, please note that Isopropylalcohol cleans too much. The print will stick too much, and rip the bed when you remove the print. Use the window cleaner for PETG.

  10. Prusa i3 is like a woman u see something is wrong but she doesnt tell u anything. U have tu discover!

  11. Got an assembled mk3s on the way and cant wait to get my hands on it. Question: Should I still do the calibration if assembled or can I print straight away?

  12. WARNING DO NOT USE ACETONE ON THE TEXTURED SHEET IT WILL FLAKE OFF. Contrary to what Josef is saying on the video at 9:59. As the the steel sheet is a consumable it isn't warranted and therefore Prusa won't replace it. This is so misleading for new users. 🙁

  13. Update:
    Do not use acetone on powder coated sheets! (10:16 is just for the smooth PEI sheet)

  14. I'm looking into 3D printers for a moment now. After a lot of research I got so hyped for a MK3s! Can't wait to get my wife around so I can actually buy one.

  15. I have the Mk2s and Love it, but man I want a new Mk3 with all the cool upgrades, like that removable plate.

  16. Just bought my first printer. Very excited. Love the quality instructional video! Very much appreciated 🙏

  17. biggest piece of crap ever , bought mine with all the bullshit add ons , after $2000 , it has been two years and it still is a piece of shit , scumbags jerkoffs

  18. I did live adjustment so many times. I printed a one layer square in the middle of the heatplate. After haven a perfect first layer I printed it again and again and discovered gabs. How can the distance between heatplste and nozzle change without doing anything ? Strange phenomenon

    By the way: you can win LDO Priya MK3 motors and filament on www.pcpointer.de

  19. Is it capable of printing with more demanding filaments like carbon/glass fibre reinforced nylon, ABS… etc…

  20. Diferent bed temperatures have to adjust z offset for each one? exemple, 1 measure at 110 degreen, and another at 80 degre,

  21. I am sooo excited!! (Typing this with one hand while holding a white sheet of paper as the printer is calibrating the 4 corners 🙂 )

  22. hello josef, will you be looking in to 3d pens at all, i have just got my 1st 3d printer but as you will see from my YT Chanel i make figures and models and all different things but mainly with 3d pen, i am yet to find a 3d pen that lasts for a decent amount of time and that has good features is this something you think you will consider in the future?

  23. can't wait for mine to arrive in on thursday. At the uni lab i have dmls sls sla and fdm by stratasys, haas and such major brands to play with, but this is my first very own 3d printer and i am excited like a child:) It took me 3 weeks to decide. I really can't wait even paid eur20 more to have guaranteed 2 day delivery:) I know the result will be far from what i've experienced with the big machines, but now i can wake up at 2am with some idea , draft it and have it ready in the morning. The choice was between Zortrax 3 and the Prusa mk3s and Prusa won by the waaay lower price , the great community built around it and the great vibe it has. And now it is miiiine!

  24. 2:00 You guys should use "-|/" as your waiting "cursor" instead of just "-|". It looks cooler and goes way back to old unix systems. I remember seeing it on Solaris boxes in the early nineties.

  25. josef has different eyes on whats clean and not 😀 well the nozzle wasnt smeared or full of old plastic but it definately wasnt clean 😀

  26. i have a creality CR10(really thinking about uppgrading to the prusa i3) and what i really hate about it is that it first needs to heat up the bed then the nozzle instead of both simultaneously. hows the prusa work in that area?

  27. Bed Leveling (P.I.N.D.A test). (5:33) Skontroluje sa výška 9 bodov. Aká je max. dovolená odchýlka medzi bodmi? Urobí sa na základe zamerania nejaká matematická korekcia tlače na sklon? Alebo len vyhlási chybu? Ako je to v novších verziách? Ďakujem.

  28. Hello I have a big big question for Josef Prusa!

    My parents give me a 3D printer the Prusa i4 do you make it or not because my parents thing that it was a good 3D printer

    I have 13 years, I am from Mexico so my English is bad, they give the printer like 3 or 2 years ago

  29. 769 € for a printer that you also have to assemble yourself, and in which several components are also even printed. What's up. What justifies this high price? The components are never so expensive ?!

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