Introduction: Printable Prusa I3 Style Mini 3D Printer! by 3Dtje

Already have a 3D printer? Want another 3D printer?! Well all right you greedy person, I'll show you how you can print your very own mini 3D printer by 3Dtje!

Why would you want to do this?

Well, lets say, you have your larger more capable printer printing high temp materials, or large objects for a project, and you would like to print small/useless/other objects at the same time.

Or, you believe in the idea behind the RepRap movement, that a printer should be able to self replicate!

Or you want to challenge yourself, and your understanding on how a 3D printer works

Or your current 3D printer is just sitting and collecting dust in the corner of your room because you have nothing else to print because you lack creativeness or the skill to design real world objects that have actual uses so you decided to browse the web and find something that does something in an attempt to prove that 3D printers have actual usefullness but settled on self replication because it seems like a worthy endeavor despite not having a solid goal in terms of problem solving.

Still with me? Let's continue...

btw the video showcases what the printer is capable of. You may require quite a bit of tuning to get it to this level, but if you're good enough, you may not need to!

Step 1: Preface

Let's be frank here... This is NOT an ultra cheap printer. This is NOT a $60 Cherry 3D printer. This is NOT a way to save money or time. This is NOT a good first printer.

Now that we got that out of the way, let's talk about what this IS.

The 3Dtje Mini 3D Printer is:

  • Pretty damn printable
    • EVERYTHING (all printed parts) can be printed in PLA
    • Everything fits within a 200x200 print volume
      • Most parts can be printed in a 100x100 print volume
    • Most parts print without supports, very little support material is used when needed
  • Very few tools needed
    • Unlike most DIY designs that require a laser cutter, CNC, or otherwise a lot of cutting...
    • You can probably get away with a drill with rotary cutoff bits, or a hacksaw to cut the 2 rods necessary to get this printer running! (In fact there might even be a way to get around this right now!)
    • No need to source MDF, or wood, or acrylic sheets, or aluminum extrusions that may be difficult or expensive to get in your region! No difficult or extensive cuts required for a frame! Maybe even no cuts needed at all?!
  • A Prusa i3 Clone
    • This design is nothing new, nothing revolutionary, but it's reliable, prints well and works with any slicer
  • Open source
    • All files to reproduce your own are hosted on Thingiverse and licensed via GPL
    • Feel free to download them and modify them as much as you'd like
    • You can even sell these if that's your thing!
  • Simple and interesting to print
    • As little as 19 STLs to print a functional thing
    • Most parts look different and are more interesting (IMHO) than a bunch of printed connectors for extrusion or rod based printers
  • Simple to assemble
    • All parts are connected via M3 screws and nuts.
      • If you live somewhere where metric hardware is hard to come by (or expensive) then this massively simplifies things.
    • Cutting up 2, maybe 4 rods, not even having to be super accurate is about the only thing you need for post-processing tooling
    • No lining up and squaring precisely of rods and angles and axises and such
    • With such few 3D printed parts, assembly is somewhat intuitive from only sets of pictures.
  • Really fricken cool!
    • Small, portable, low mass moving parts! This printer can print FAST! (when tuned properly)
    • Something you made yourself!

Now that we're on the same page Let's get started!

Step 2: Prerequisites

You'll need a 3D printer. Or know someone with a 3D printer. Or you know, just be really good with converting STL files to physical form using your hands I guess...

  • Print volume of at least 200x200mm XY, and maybe 200mm Z if you want to print rods as well lol
  • 1kg PLA, or some similarly rigid material. Carbonfiber filled PLA comes to mind, however bog standard PLA works great
    • I honestly don't know how much filament this uses... Probably around 500g or so
    • ABS may be desired for the extruder design if you don't/cant lower your motor current
  • Tools
    • Screwdrivers for the screws you will be buying
    • Pliers, files, etc for cleaning up printed objects
    • Metric drill bits for opening up / cleaning printed holes
  • Knowledge of how to build a 3D printer from scratch
    • This is not a hard requirement but knowing how to solve common printer issues will reduce the amount of swearing you may find yourself uttering when things don't work out perfectly the first time
      • While I'll try to help you as much as I can (or am willing), you should come into this project having built at least one "from scratch" kit, where the soldering of electronic components is about the only thing that you didn't have to do to build a printer.
      • You better be good at troubleshooting and solving your Marlin firmware issues, because you might run into them. I've included some issues I've run into, however it is definitely not all encompassing

    Meet the requirements? Good! Don't meet the requirements but want to read on anyway? Also good!
    Let's see what else we need...

    Step 3: Vitamins (non Printable Parts)

    Vitamins will probably run you around $150ish USD. More if you want your parts from China to arrive sooner

    Full BOM is located here

    It's a little hard to read, so I'll just say that the items and prices on the left are what you want to buy, and prices on the right are what I ended up spending.

    If you just want a "functional" model without having any sort of precision or quality output, you can follow the "Can be Printed" column and just not buy those parts to save a little bit of money.

    Printer Pictured above:
    All parts printed and loosely assembled
    Threaded rods, screws, nuts, and motors are the only non printed pieces in this picture. It can be turned into a functional printer with a minimal amount of hardware + electronics

    Step 4: Printing the Parts!

    Now this is the easy part!

    Visit the original thing here and start printing!

    Things to note:

    • I printed the Z axis stepper motors lying on their side instead of the shaft side down. This gave me a much cleaner

    DO NOT print the following items

    • Extruder housing 2, 3
    • Y axis tensioner
      • My 0.3mm clearance printer could not print this in a way that would fit in the Y axis
      • I ended up shrinking this
      • Print the one in the parts pack (below) instead if you want a "smaller" one that has a better chance of fitting.
    • Left X axis

    Now for my role in everything

    This is my parts pack that contains modifications to use non standard parts like imperial rods, printed bearings, printed rods, etc.

    For the cheapest/worst version of the printer, print everything and use 3/16th" rods lol

    For people going for quality, you may just want:

    • Y axis tensioner
    • 10mm Extruder housing
    • Marlin 1.1.7 config files

    Step 5: Assembling Everything

    I'm kinda lazy and I think that this is fairly simple, so instead of telling you how to assemble everything step by step, I'll provide a few pictures to help you puzzle things together.

    Here are some helpful hints I wish I had when I was assembling my first one


    I probably should add a lot more to this section than what is here currently, but I am unsure on what to add. Except maybe take things from the google drive and put them here... Let me know in the comments if you have any ideas on what to add here!

    Step 6: Assemble Frame

    Fit things together like the pictures shown LOL. Ignore the rods for now, and ignore the bed for now. The rest of the parts should be self explanatory.

    Step 7: Assemble Y Axis

    If your motors are anything like mine, you'll need to attach the gear/pulley on the stepper motor where the gear actually extends past the shaft length to get things to line up.

    Step 8: Assemble X Axis


    Depending on your printer, you may need to do a 3mm drill of the Left X axis piece's belt tensioner hole. This hole needs to be somewhat loose as to freely put tension on the tensioner.

    1. Attach a motor to the end of the X axis with the connector facing downwards
    2. Attach the 20T gear
    3. Insert the 6mm x 180mm rods into the holes on the motor side. You will need to cut these rods if you bought the 200mm stock.
    4. Assemble X axis tensioner either with your own idler gear, or printed idler bearing. Ensure that the M3 nut is in the tensioner before you proceed.
    5. Run the Gt2 belt through the Left side (motor side), through the gear, through the idler bearing on the right side and make a loop so that you can sorta measure how long a belt you need
    6. At this point you should probably mount the right side of the X axis on the rods so you can attach the X belt tensioner
    7. When you are comfortable with the length (ensure the X axis tensioner is recessed quite a bit) you can cut the belt. Be sure to leave some extra length just in case your measurements were off.
    8. Remove right X carriage piece
    9. Attach LM6UU bearings into X carriage
    10. Slide your X carriage (without hot end) onto the 2 rods
    11. Reassemble
    12. With everything assembled, take your belts and attach them to the X carriage
    13. Tension the X belt slightly with the tensioner screw, and check motion. Don't need to fine tune things yet, but you may need to adjust the stepper motor gear's height to ensure that the belts are not rubbing on anything.

    Step 9: Assemble Bed

    You'll need to zip tie 3 LM6UU bearings to the bed using tiny zipties

    Attach the whole thing into the Y axis with the 200mm x 6mm rods. They should slide into your Y axis fairly tightly

    If the rods are too loose for some reason, print out my Y axis rod-cap and install that on the affected end(s)

    Follow the same process as the X axis to determine Y axis belt length. Use a small 5mm or so length of filament to help space and retain the belts in the space provided on the bed. This will attach the bed to the belt.

    Step 10: Combine X Onto Z

    I don't have any good pictures for this step, but basically, get your threaded rods in, slide them into the couplers, and then slide the 6mm rods through the holes in the top

    Assemble as shown in the picture lol. Post in the comments if you have any idea on how to improve the clarity of this step!

    Step 11: Download and Upload Marlin


    Yep, not helping you on this.... This is where your previous 3D printer building experience comes in. I'll try to clarify things in the comments if you ask questions, however I'm not entirely sure how to make it clear and concise.

    Follow the instructions here
    Or watch one of the many youtube videos "Install Marlin on RAMPS"

    When they all say to "configure" your stuff, instead what you can do is, so long as you've downloaded Marlin 1.1.8 Go and download this

    Inside the Zip, you should see

    • Configuration_118.h
    • Configuration_adv_118.h

    Remove the "_118" from both of the file names and copy it into your Marlin folder before you click on the Marlin.ino file.

    Open up the Marlin.ino file

    Review or set up your steps per inch (dependent on your steppers, drivers, extruder gears, etc).

    Upload to your Arduino, and if you've done it correctly, you should see something popping up on your LCD and you should be able to control the menu!

    Step 12: Add Electronics


    And that's all the help you're gonna get :)

    No seriously though... This is also where knowledge on 3D printing will help you. Follow the wiring in the diagram provided (you wont have an auto level switch though)

    BTW, before you assemble the whole thing, you might wanna check if it actually works... Take your board you flashed with Marlin, connect up the LCD and connect a stepper driver and a motor to one of the outputs. Power everything up with your power supply, and go to Prepare -> Move Axis and see if you can get the motor to run. If you can, great! You can finish assembling the thing. If you can't hope nothing blew up or go and troubleshoot. Leave a comment if you get stuck at this step.

    You're gonna want this link to help you with setting microstep jumper settings. If you've gone with the A4988s, just fill all 3 jumpers per board, otherwise it may do strange things. If you've gone with the DRV8825s then pick whatever you want.

    After you check that things move, you're gonna need to tune your stepper driver current. If you have DRV8825s, they're probably tuned for WAY too much current.y The A4988s aren't as bad from the chinese factories. You're still gonna wanna tune them. Here's a link to get you started

    Cable management on this printer is not fun.... You're on your own since I haven't fully solved it either...

    Step 13: Gcode Start and End Statements

    Open up your slicer and load in the G-Code statements

    The ones I like are in

    Named 3Dtje_Gcode_start_stop.txt

    Add the start and stop Gcodes in their appropriate locations in your slicer.

    BE AWARE, my printer does not have endstops, so I do not have a G28 line in the Start code. You may need to add this into your Start code if you want to take advantage of this

    Step 14: DONE! Preflight Checks...

    Set 0x0x0 position by hand (if you don't have/use endstops or are using my X carriage)

    Level bed

    1. Preheat nozzle to temp
    2. Take a piece of normal printer paper
    3. Rub the paper between the nozzle and the bed
    4. Manually turn the Z axis motors until there is just the right amount of friction on the paper
    5. Repeat on both left and right sides of bed until friction is even throughout left and right sides

    If you're using Cura, you can import my super fast profile into the printer
    This is the 3Dtje_superfast.curaprofile file. Import it into your printing profiles.

    Or just go with the default cura profile, that super fast one is more for advanced users that can troubleshoot when things start underextruding or steps skipping.

    If you're really worried, you can print at 20-30mm/s all day long just fine :) might take a little longer, but the printer is small anyway!

    Step 15: PRINTING!

    Load up an STL into Cura or whatever and hit print!

    Step 16: Troubleshooting...

    Unless you build printers regularly (in which case, why are you reading this?!) Most likely you will have encountered some sort of issue during the build process (becuase I missed something important)

    If you were smart or lucky enough to have your machine printing "something" but your prints have failed, then it sounds like your printer or print settings need tuning.

    In either case, visit the page here: and post a comment! A couple of us check the comments regularly. If you aren't hearing from me or anyone else on the comments section in instructables, I'd suggest going there, that way you can get feedback from more than one person.

    Here's a link to a very messy,unorganized repository of files and notes pertaining to the 3Dtje. I may have missed something in this instructable, but it may possibly be hidden in here...

    Pictured above:
    Orange flat pieces:

    • X axis tensioner "opens up" the gap between the belt. The X carriage will gain more and more friction the closer it is to the X axis tensioner as the belt will rub against the carriage.
    • Ensure your Bearing/printed cover is smooth/lubricated
    • Move the tensioner as far "into" the right X carriage as possible to avoid belt friction against the carriage.

    3 marvins and 2 half marvins:

    • Half marvins were due to under extrusion because of a faulty thermistor.
    • Compensated by increasing the temperature.
    • Replaced the thermistor eventually.
    • Make sure that your particular thermistor is set in Marlin correctly.
    • Z banding is visible in the bottom ones.
    • Make sure that your 6mm Z rods sit extremely tight in their holes and that the threaded rods do not rub much on the top.

    Good luck and happy printing!

    Step 17: Print Quality Examples!

    Well, now that you've gone through all of this trouble to build your very own 3Dtje. Does it print perfect? Probably not! Curious to know what this printer is capable of once you tighten everything down and fine tune your filament printing profile settings?

    Check out the images provided!

    General print settings are in the image themselves.

    Acceleration is set to 3000mm/s^2, Jerk is 40mm/s^2 as provided in the cura printing profile in my parts pack!

    Ask questions if you're running into print quality issues and I'll try to help as best I can!

    Good luck!

    Arduino Contest 2017

    Runner Up in the
    Arduino Contest 2017

    Epilog Challenge 9

    Participated in the
    Epilog Challenge 9