I just got my first 3D printer, the Geeetech Prusa I3 X. This post details my experience as a 3D printing newbie from unboxing, assembling and using this 3D printer. First, let me show you what this printer can do.

Here, I'm printing an Atlas statue to hold up my colleague's monitor.

Safety tips

  • Never plug or unplug cables from the controller board while the board is powered. This can damage the board or motor controllers.

  • This thing gets HOT, don't let little kids touch the build plate or nozzle

  • PLA is foodsafe and the fumes are probably not too toxic when printing. However, ABS is NOT foodsafe nor are the fumes safe. Be sure to run the printer in a well ventilated area while printed ABS.

Other Parts

Update Nov 2016. I have found after several months of use that the bearings do wear out. They are easy to switch out, but be sure to order some extra.

Along with the printer, you'll need some filament. You can get this from Banggood for about $30 per kg, but if you live in the USA, I suggest you get filament from this Amazon supplier for only $8-10 per kg. The ratings for the Amazon filament are not great, but I've been using this for all my prints and it works fine.

From time to time the nozzle does clog, so having some extra nozzles on hand is always a good idea.

To get the prints to stick to the print bed, I have found that Elmer's washable (purple) glue stick works well for both PLA and ABS. Also, it is much easier to work with than ABS juice and gives a similar result. Glue stick can be cleaned off with rubbing alcohol. Alternatively, if you don't want to mess with the gluestick, get a PEI sheet and print straight onto this surface without any preparation.

I just ordered a PEI sheet, in hopes of making printing even easier. I'll post an update when I get this installed.

Finally, you'll want some 100% pure acetone if you're working with ABS. It's useful for gluing parts together, as acetone melts ABS. Mix equal parts Acetone and some plastic from failed ABS prints to make "ABS Juice," which can be used to glue parts together or adhere prints to the print bed. Acetone can also be used to clear clogged print nozzles, by soaking the nozzle in acetone overnight.


Part 1

Part 2


Download the build instructions here: http://www.geeetech.com/Documents/Building%20Instructions%20of%20Geeetech%20Prusa%20I3%20X.pdf

I found it easiest to follow the PDF and watch the youtube videos when I had questions.

Here are all the parts.

Checkout how the bag numbers correspond to Part ID in the directions.

General Tips

In this guide, I'll refer to the axis of the printer as described in this diagram.

Use blue thread lock wherever you have metal on metal, however the blue thread lock will degrade the acrylic frame, so be sure to not let the thread lock touch the acrylic! The only places I was able to safely use lock tight was on the motor couplers.

By the way, bag 38 which has the motor couplers, also has some allen wrenches you can use for assembly.

Also, they don't mention this, but bags 7 and 8 include 3mm and 4mm washers, use them whenever bolts in bags numbered 22, 23 and 30 are used. This will help strengthen the frame.

Step 1 - Threaded Rod

Step 2 - Y axis plates

On this step, I got everything assembled, then used a ruler to make sure both sides were square. Adjust the outer-most nuts if one side is longer or shorter than the other.

Step 3 - Y axis motor

I found that mounting the gear upside down actually fit best.

Step 4 - Pulleys

Here, the quantity of M3x20 screws in the manual is 3. You only need 1. Also you'll need a M3x50mm screw for the other pulley. The Youtube video labeled this as M3x40, but it says M3x50 in the manual. Since my kit didn't include M3x40, I'll use a silver M3x50 screw (Bag #28 in my kit).

Also, the pulley brackets came a little bit too snug, so the wheel couldn't turn freely. I used a pair of needle nose pliers to open them up a little bit.

Be very careful that there is enough clearance when installing the bearings and that they can spin freely without contacting the edge of the bracket with any pressure. I destroyed a bearing because it rubbed on the edge of the bracket. Open up the bracket a little extra if in doubt, to make sure there is enough clearance.

Step 5 - Print Platform

The washers go between the bolt head and the acrylic.

Unlike the video, this kit uses only 1 rod-holder thing per rod, not 2.

I also tightened down the bolts on the threaded rod before tightening the rod holders, so everything stays the same size.

Step 6 - Y-belt

I don't have a hole punch, so I used a Dremel on slow speed with a milling bit to punch the holes, but you could pry just drill through the belt. It's fairly stiff.

Make sure you loosen the screw on the y-axis pulley thing all the way, to give as much slack as possible while installing the belt. Once you have the belt screwed into the carriage, then tighten the y-axis pulley.

Step 7 - Left Z motor mount

Be careful in this step, not to over tighten the screws that hold the acrylic pieces together, as they could crack.

The trick with these is to get all the acrylic pieces loosely attached, then once everything is in place, tighten them all down.

Step 8 - Right Z motor mount

Same as the left, be careful not to over tighten!

Step 9 - Side Panels

Again, be very careful to not over tighten the screws.

Step 10 - Main frame assembly

This step isn't well explained and the pdf directions show that you need more square nuts than you actually need.

Basically, you want to attach the main frame and the tray, like this.

Step 11 - Fan mount

This one is straightforward, just screw in the fan. It would have been easier for me if this was included in the kit, but it seems like they forgot to include it.

Step 12 - Z motor assembly

I used thread lock on the screws in the motor couplers.

Step 13 - X axis motor ends

This bit was rather long, but not too hard, just follow the directions.

I did wonder how long to make the gap between nuts on the (really long) endstop screw. Here is how long I made mine. Basically I wanted it to be as long as possible, while making sure the top nut was not able to come free.

The final part of this step uses a different linear bearing than in the video.

Refer to the PDF or these photos to see how to mount the same kind that we're using.

I used a spare steel rod to ensure that they were aligned while tightening.

Step 14 - X axis idler

The hole for the smooth rod was too small, so the smooth rod was rubbing against the acrylic when inserted. I used my reamer to add 2mm to the diameter of the hole.

Step 15 - Extruder Carriage

Step 16 - X & Y Axis Assembly

In this step, if the threaded rod is difficult to turn, try adjusting the nuts on the brass coupler to slightly change the orientation of the coupler.

Step 17 - X Motor

Attach the geared bushing to the X motor.

Mounting the gear flush with the end of the motor shaft seems to provide the best alignment.

Step 18 - X Axis Belt

Step 19 - Mount the Extruder

Use some 4mm washers if you still have some left.

Step 20 - Install the LCD

Step 21 - Mount the Control Board

Step 22 - Build Platform

Wires go out the back.

Use washers from bag 7.

I found it easiest to hold the washer and wingnut in one hand while using a hex driver to start the bolt threading from the top, then tightening the wing nut by hand.

Step 23 - Power Supply

IMPORTANT! There is a switch inside the power supply that will change it between 110 and 210 volts.

If you're in the US like me, you'll want to switch this UP to make sure that it has the correct 110v input selected.

When you mount the power supply, there are 2 sets of holes on the top, very close together. Make sure you use the slightly lower holes so the bottom holes line up.

Step 24 - Y Endstop

Then mount the endstop, using washers from bag 6, which they don't mention anywhere.

Step 25 - Wiring

Here is the pinout:

Here are the axis names and directions for the end stops:

Here is what mine looks like, all wired up:

All the end stops are at the MIN of the axis, so make sure to use the MIN plug for each axis.

There are 2 Z motors, hence the two plugs.

Connect the extruder fan to FAN 1.

There was no individual video for this step, so skip to around 36 minutes into the overall assembly video:

Bag 49 has the cable wrap.

Bag 57 has the extruder fan extension.

First print

Ok. I got it all assembled, then I had no idea what to do, so I turned it on.

It had a few problems, the fan was loud, so I bent it back into place and it was quiet again.

Then I thought, now what do I do. Wellll... print something I guess!

To actually print something, we'll need an .stl object file. We take this file and load it in our slicer.

Model Slicer

Download an .stl model from youmagine or thingaverse and the slicer, Cura.

Install Cura and import your .stl file

Pick the type of plastic you're printing, ABS or PLA. The default temps in Cura work fine for me. I have found that the max temp I can easily get on the print bed is 85 or 90 degrees, so I usually keep it at that for ABS prints. 60 degrees for PLA is no issue.

There are 2 options you'll want to update. Under Machine set nozzle diameter and set layer height to something around %50 of your nozzle diameter.

I have a .3mm nozzle, so I usually use .15mm layer hight for high quality prints and .2mm for slightly lower quality, but faster prints.

Once you've set the settings above, the .gcode will be generated and you can save this to a file. Save it to an sdcard with a descriptive name.

The Geeetech Prusa i3 has an SDCard onboard that makes it possible to print without attaching the printer to a computer. To calibrate it the first time, I found it easiest to hook up to OctoPrint

The other option is Pronterface. It has less features, but is easier to install and get running. To start using it, plug in the USB cable between the printer and your computer. Then in Pronterface, connect at BAUD 250000.

Just like OctoPrint, Pronterface lets you control the motors via the GUI on your computer. I started moving around the motors with Pronterface and found that the Z motors were stuttering and not turning properly, so I turned everything off. Then I adjusted the little screw on the Z-Axis motor driver, turning it right about 15 degrees. This was enough to increase the power slightly and it moved!

Next, I used the home buttons in Pronterface to let the printer find its "home" position.

Finally, I adjusted the bed by moving the print head to each corner of the print bed and using the screws on the print bed to level it. I used a business card to check the distances.

While I was running the Z axis motors, I lubricated the threaded rod with some CLP BreakFree lubricant, which contains PTFE (teflon).

Setup and calibration

Note when setting up and calibrating, the extruder motor will not run when the hot end is not hot, so to test the hot end, be sure to heat it up first.

I noticed the edges of the print bed are about .5mm higher than the center, so be sure to calibrate the center of the print bed as well as the edges. Also, the deflection of the aluminum print bed changes significantly with temperature. The greater the temperature, the greater the deflection in the middle of the bed, so when I print ABS at 90 degrees, I need to adjust the Z-Axis endstop screw, loosening it by 1/3 of a turn.

After a few prints, my X axis was binding, so I turned off the motors and checked how hard it was to move by hand. It was quite difficult, so I added some CLP Breakfree lubricant to both rails and moved the extruder manually until it moved without binding. I also increased the POT on the X axis to 1.1v, just below the 1.2v recommended max.

Extruder Calibration

This is the one thing you'll want to do to calibrate your printer, measure and set the amount of material extruded as follows to avoid under or over-extruding.

You'll notice there is a problem if there are gaps in your print or the walls look like they're oozing.

We'll tell the extruder to extrude a certain amount of filament and then compare it to the amount actually excluded.

Mark the filament 150mm above the top of the extruder.

Run this command to extrude 100mm of filament at 90mm/min: G1E100F90

Now measure the mark on the filament to figure out how much was actually extruded.

Run M503 to see your current steps per mmm.

new steps per mm = (old_steps_mm) * 100 / extruded_length

Set it with M92E[new steps per mm value here] then run M500 to save.

Watch Tom's guide here https://youtu.be/YUPfBJz3I6Y

Viewing your current config

To view your current EEPROM configuration, run M503.

You can learn more about firmware calibration here: https://youtu.be/2RbcMvhatjU

Belt Tension

The first thing to calibrate is the belt tension. We want it as tight as possible, but not too tight such that the axis binds (e.g. can't move). Start by lubricating all the bearings and linear rods by covering them with a PTFE lubricant and moving them to every extreme. I used CLP Breakfree:

Now tighten one axis while moving it with your hand. Tighten it until you can't move it, then backup a bit so that it moves freely with little resistance.

If you pull a belt and let go, you should get a nice guitar-like humming noise.

Bed Leveling

Next, you'll want to level the bed. Do this by moving the print head to each corner of the bed. At each position, place a business card between the build platform and the nozzle. The card should just barely fit, resulting in a gap between the nozzle and the bed around .1mm to .2mm.

Once the bed is level, you'll want to adjust the auto-home distance between the head and the bed. Since the platform will deform slightly when heated, you'll want to do this with a hot build platform, so using the LCD, go to Prepare -> Preheat ABS and pick the first option Preheat ABS 1. Once the bed gets up to around 90 degrees C, use OctoPrint to move the print head over the bed then auto-home the Z axis. Using the business card again, check the distance between the build plate and the nozzle. Use the Z-axis endstop screw to adjust the distance, using the OctoPrint home button between adjustments.

Bed Preparation

There are lots of discussions on the interwebs about the best way to get your prints to stick to the print bed. Through a bunch of testing, I have found that purple (washable) Elmers glue stick is the easiest and most effective way for me to get prints to stick. I simply glue stick the bed before printing and it lasts around 10 prints. When it no longer sticks, I clean the bed with rubbing alcohol and re-apply the glue stick.

I just ordered a PEI sheet, in hopes of making printing even easier. I'll post an update when I get this installed.


The firmware is available for download here http://www.geeetech.com/forum/viewtopic.php?f=20&t=17046, look for the section title 2) Firmware for Prusa I3 X(GT2560)

Here's a direct link to the zipfile: http://www.geeetech.com/forum/download/file.php?id=1589&sid=4474d46075a042b461d3f059c8597de1

Though the printer comes with firmware pre-installed, you'll want to have the firmware available if you want to change and save any firmware settings.

I did not update the firmware on my printer, and it works fine.



One of the first upgrades I made was printing one of these PLA cooling fans for the MK8 hotend. Since there is no dedicated fan, you can use the main printhead fan when printing PLA, as it does much better with active cooling.

Grab a a PEI sheet for hassle free printing.


Since this printer only comes with a 15 amp power supply, I decided to pickup a new 30 amp power supply, and this one fits in the same mounting holes: 12V 30A 360W Switching Power Supply.

Auto leveling bed

I just ordered a NJK-5002C Hall Sensor Proximity Switch to do auto bed leveling as described by Tom here:


I also got some 12v LEDs to wire onto the extruder carriage.