BLV Ender 3 Pro


I am very excited to introduce to you my new BLV Ender 3 Pro Upgrade project.

designed for the popular Ender 3 Pro - 3D printer. The project's goal is to take your beloved Ender 3 Pro printer to the next level.  By using only aluminum parts, mgn12 linear rails, BMG dual drive extruder and more, you will gain maximum accuracy, efficiency, and high print quality.



  • Fast, reliable, accurate
    The linear bearing and Delrin Wheel Gantry commonly used at most of the low-mid 3d printers as a cheaper solution for linear motion. well, ye... it's cheaper but at the expense of accuracy and reliability. linear guided rails (mgn rails) are a way more rigid, extremely precise and smoother then linear bearing or Delrin. shorting print time without compromising on print quality. There seems to be a good reason why they are mostly used with high-end 3D printers. I found cheap Chinese mgn rails at Aliexpress and thought to myself why not? So If you are already tired of the frequently worn POM wheels or the constant need to strengthen the wheels - you came to the right place.

  • Rigid parts
    This time I chose a different path. as you know 3D printed parts are a bit flexible and I wanted to take it out of the equation. by using CNC machined parts, we can take our printer to the next level of accuracy. for testing I have used a BT dial storing the data into a database on my pc, then after more than 2000+ loops, measuring, again and again, the accuracy (uniformity and deviation). without any doubt - the aluminum parts highly improved the results compared to 3D printed parts.

  • Accessible
    CNC machined parts are expensive, right?
    In trying to make it cheaper, I decided to give all my work for free for commercial use under one condition - my permission. part of the cost is the hours required for designing those parts (it took me more than 200 hours of work) by saving it to the manufactures the kits can be cheaper. for example, while 4 aluminum parts being sold at 30$+ on Aliexpress - This kit has 16 pcs and costs 59$ including belts, screws, and shipping! Sure you can find other aluminum + rails kits but unfortunately, they cost 300$ and more.
    Now, I bet you are asking yourself something...

  • Open Source
    where is the catch? why is this guy giving his work for free?
    a couple of years ago I gained all my 3d knowledge from this awesome community. I really appreciate the 3D community and love this hobby. So it's kinda my way to give back. this is also the main reason I made my previous projects BLV mgn Cube and the BLV anet mod. Yes, it's not easy. a lot of work especially when you got precious wife, 2 lovely little kids and a day job (which is not related to 3d printing in any way). but this "Thing" is my therapy (i think.. ☺️). I don't mind sharing my work. 10 years ago, the 3D FDM patent expired, sharing and experiences was the base to what we are having now. imagine if we had none of this and each one kept his finds and work to himself...
    I hope it could give you an idea of what I believe my friends :)







  1. Read, understand and prepare yourself
    Start with reading the Thing description, watch the 3d animations video and make sure you understand the printer structure.


  2. Get the needed parts
    prepare all the needed parts, spares of T-nuts, screws and all the tools you need. also, mentally prepare yourself :)


  3. build
    now the fun begins. It is crucial to have a precise structure for excellent printing results. there are a couple of Youtube videos that can help you, showing how to align the Ender 3 Pro frame. while installing the mgn rails, please use the provided JIGS - the assembly will be much easier. Take your time when fixing the rails to the extrusions. I found a good quick video tutorial made by 3D distributed: ( showing an easy way to align parallel rails.


  4. Electronics installation
    If you have decided to install the SKR mini E3 V1.2 board, you will find an excellent Youtube guide showing you the right way to install the board. mind that it's the same with the DuetWifi 1.04 board (if you are crazy enough).


  5. Software, Tests, and Calibrations
    This is the scary stuff - when you must know what you are doing - or just watch the thousand youtube videos explaining how to calibrate your Ender 3 Pro. My advice is to replace the Original FW with a fresh version of marlin following one of the Youtube masters. Please, don't forget to do the following steps:

    • wiring check + endstops check

    • updating your FW (to a freshly updated marlin version).

    • extruder calibration

    • Feedrate calibration

    • Hotend PID

    • Bed PID

    • Prob Z offset / Z offset

  6. print
    Enjoy your printer and give her love when needed :)
    maintain your printer by greasing the rails with a Lithium white grease or a light sewing machine oil. Keep the rails clean and the belts tight.
    Also, Clean your PEI build plate with alcohol after every print and scratch them a bit with brass wool if they are new.


  7. Post an "I made one" pictures
    Show the world your new 3D printer and be proud of your creation:)
    I would appreciate it if you could please upload your newly built 3D printers pics. Knowing that it helped you create your own 3D printer - for me, it's worth all the hard work and many hours that I spent in this project.


  8. Remix & Share
    I am 100% sure that there are many ways to make this printer even better. this is why I gave you the source file of the project. Make it better by sharing your remixed and share with this awesome community:)


  9. Make it?
    If you would like to use it for Commercial use - please read the "Legal Licence" section.




Ender with shadow.png


Important note: if you are planning to use the original Z endstop and NOT the bl-touch or any other leveling sensor, please use this adapter for the z endstop



If you already got the Blurolls kit with rails included - please skip the parts of the rails.

2 options for the rails

Notice: Hiwin rails should be tested with a load on the carriage)

mgn carriage warning.png


Choose your Hotend
I highly recommend upgrading your hotend to a decent one. First, you need to decide whatever you want to stay with a Bowden system or try the direct drive option:


Use the two screws for alignment only, then disassemble them.



choose your preferred Z setup:

  1. Single Z stepper
    I used this method for a while and I found it satisfying, however, moving to dual Z would defiantly add even more rigidity to the motion system and dramatically improved the Z-axis.

  2. Dual Z using one stepper
    1 x Dual Z kit using One stepper, 2 threaded rods, and a belt.
    you can gain back some of the lost Z height by using This BMG bracket
    note: Although I lost some of the build volume height (the extruder touch the left top plate) I found this method really good and it became my favorite. I would strongly recommend replacing the dual z kit's original Philips screws with Hex socket head screws from a local shop.

  3. Dual Z using two-steppers
    This is the recommended option for this kit.


Please note that using this method will decrease your Z height since the BMG can touch the top plates.





Filament I Used







The original Creality belt is too much flexible decreasing the printing quality. as part of the kit, you will get fiberglass-reinforced GT2 6mm belt which is way better than the original belts.
The X-axis Belt clamped with a different size of 785mm length (It's the belt's length between the clamp - not including the brass clamps).
Note that if you need to replace the belt you can use a Ziptip to lock both of the Belts ends (i will upload later a small graphic guide).


Build Volume adjustments

In order to keep the original build volume size, there is a need to change the Y_Min_POS value that can be found inside the Configuration.h file on marlin.
my calculation came to the value: -9.15 for Y min. you are free to change the value to be suitable for your needs. The following picture will help you locate the Y_MIN_POS value.

adjustments biuld volum.png




Dual Z - reposition your PSU

For the dual Z option, you would have to reposition your PSU unit:

  1. Disconnect the PSU from the wall.

  2. Disconnect the PSU from the printer.

  3. partly disassemble the plastic cover from the PSU.

  4. drill M5 holes as shown below.

  5. insert 3 x M5 8mm button head screws + T-nuts.

  6. reposition the Plastic cover on the Frame and tighten the screws.

  7. put back the PSU and lock it back to the cover.




Smart Filament Sensor

So What is special so much with the SKR Smart filament Sensor?
at first, I was confused. Why should I buy a 15$ filament sensor when it can be made using a small wire + Endstop switch worth 1.5$? After watching this video I immediately understood what is the potential.
filament "sensor" with a switch can only identify if you have a filament or if you are out of filament. but what will happen if your filament spool jam/filament will be stuck? nothing.. your printer will still keep printing blank. The smart filament sensor can identify if the filament moves inside using a rotation encoder. if your filament suddenly jams and stuck - it will pause. worth every cent especially if you are printing huge prints (12+ hours prints).
Big like on this Smart Filament sensor!


PEI Surface

After a long time using the Energetic PEI spring steel sheet, I wanted to test the Trianglelab new Spring steel double-coated PEI sheet (long name..) it came well packed with alcohol wipes and a manual - yes, a printed manual!
unfortunately, the first try was a complete fail, the corners started to lift and the prints were a complete fail. but then I decided to read the manual that came with the PEI. The last tip on the manual made the trick - Just scratch the PEI with Brass wool really good and your prints will stick to it really good. unlike the Energetic PEI when the PEI sheet cooled down it was easy to release them from the bed.


Leds Installation

For this task, you are going to use A 5V 60leds/m (60 LEDs per 1 meter) non-waterproof strip that can be cut after every single led. the non-water proof will be easier to slide into the V-slot channel.

  • Cut 15 LEDs strip and solder a long cable (4 wires) to it. Then, slide it into the top V-slot channel.

  • Cut 3 LEDs strip and solder a cable to it, then using 2 zip tip, secure the small LEDs strip to the rear of the Transparent BMG extruder

  • connect both wires together, make sure it was connected correctly.
    Now you have two options:

  • Connect it to the RGB LEDs controller (simple) and use the IR remote control

  • Connect it to the SKR Mini E3 LEDs pins and configure it.


Bed Carriage Springs

Please replace the Ender 3 Pro original Bed springs with the springs Yellow Strong Creality CR-10 Bed springs. Your bed will be way more stable using these springs.


Trianglelab DDE

How to install the Trianglelab DDE system

  1. Please print the Carriage template.stl

  2. place the drilling template on the rear side of the DDE system

  3. Drill two holes as shown at the picture with a 6mm drill bit to 4mm depth.

  4. remove the template

  5. install the DDE system on the X- carriage


Additional Printed Parts



MGN12H rails & Carriages extra info

Well, i used cheap Chinese mgn12H rails from Aliexpress cost 18$ each.
After buying from 4 different Aliexpress sellers i found the best rails sold here, at "CNA Mechanical Parts Store" store.
I even not needed to clean the rails! The block is sliding smoothly without the need to clean it. Wonderful rails, highly recommended!

Please be careful and DO NOT buy rails from: "RDC Official Store" nor "linkcnc Store" at Aliexpress. "linkcnc Store" sold me an awful rail which was used, damaged and shorter then what i ordered. even after cleaning and lubricating it was still stuck and jammed "RDC Official Store" started to ship mgn blocks with non mgn standard size, so i can no longer recommend on him.

Cleaning and lubricating

notice that the mgn rails you'll get will not be smooth as it should be.
at the factory, they lubricate it with a protecting oil that needs to be cleaned away. There are some videos on YouTube showing how to clean the carriage with WD-40.
Don't forget after cleaning both rails and carriage to lubricate it with sewing machine oil or Teflon silicone grease.
As for smoothness: Please ignore the method for testing smoothness by tilting the rail - it's wrong! You want it to be smooth but not too much.
Also, since its miniature rails, please don't use too thick grease for lubrication.

Cleaning mgn12H carriage video
it's a pretty good video. just use a container in order not to lose steel balls
note: after assembling all steel balls, you will be left with empty space of one steel ball.

fixing the mgn rails can be very frustrating. it needs to be perfectly aligned and straight. else, it will give you a headache, so don't start this project without tons of patience.







BLV mgn Cube - 3D Printer by BLV  (Ben Levi) is licensed under the Creative Commons - Attribution - Non-Commercial - Share Alike license.


Legal license

If you would like to manufacture the BLV Ender 3 Pro Kit (Aluminium parts).
Please contact me:

the files could be used for Commercial use (free of charge) under one condition - my permission only!
I will provide you additional important production information and guidance.
In order to make it accessible, I am not charging for the files any money. I prefer letting the "market forces" do their magic and make the set affordable for all while they are free.
please mind that you must add a designer Credit to the listing - "designed by Ben Levi" and add a link to the Thingiverse project.

Please notice:
I highly recommend avoiding anyone who claims to be my "business partner" or asking for free parts on my behalf. I am a self open-source developer that have no other partners and no one represents me other than me. I will never ask for free parts or money.
So, please avoid scammers. Thank you.