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MPCNC - a printed CNC milling machine!

Mrxnnx 6930 19
This content has been translated » The original version can be found here
  • Hi! Another project for my workshop equipment is MPCNC, i.e. a CNC milling machine printed on a 3D printer, today I will share my humble opinion with you (no time for testing, session at PW :( ).

    I always wanted to be able to precisely cut elements in wood, plexiglass and aluminum. I couldn't afford ready-made milling machines, so I decided to build my own :) The milling machine elements were printed on the printer which he writes about here: Link
    Before further reading I present the still not finished MPCNC:

    MPCNC - a printed CNC milling machine!

    THE PROJECT IS NOT MINE AND IS GENERALLY AVAILABLE AT THIS LINK: Link

    Elements needed for construction:
    - PLA 2kg about PLN 120
    - 500W air-cooled spindle 350 PLN
    - Nema 17 engines 5 pieces PLN 150
    - Belts and gears about PLN 20
    - Pipes (I had) the approximate cost is about PLN 50 for the pipes that I used
    - Bearings, probably 608RS 60 pieces, about PLN 60
    - Screws (various types) about PLN 50
    - T8 trapezoidal screw about PLN 10
    - Flexible coupling to nema 17 about PLN 2
    - 12v 500W power supply (I have from old servers from my dad from work)
    - Ramps 1.4 + Arduino Mega 2560 about PLN 60
    - DRV8825 stepper motor drivers 3 pieces about PLN 10

    The total cost, not counting the plywood as a table top, is about PLN 900

    Before I start talking about whether it is worth mentioning a few more nice and thoughtful aspects of the machine.

    The first thing is fixing the straps on the cable ties, there is no problem with tightening them:
    MPCNC - a printed CNC milling machine! MPCNC - a printed CNC milling machine!

    Second thing is nema 17 motors, no need nema 23 because of two motors on X and Y axis.

    Easy to use and build for everyone, there are tons of descriptions and tutorials on the internet :) and some of the works that someone squeezed out of this machine are beyond belief :)

    Due to the large number of guides on how to assemble and configure the machine, I will skip this topic, but I will only mention that there is a modified marlin on the arduino :)

    MPCNC - a printed CNC milling machine!

    An important aspect of the machine is that you can theoretically get an unlimited working area, it is enough to buy longer pipes (for me the working area is about 70x50cm) :) but everyone knows that this is not possible mainly due to the lack of stiffness, so the smaller and lower the better :)
    MPCNC - a printed CNC milling machine!

    No more praising, time for machine trouble. The first main problem is the low stiffness of the original structure, you have to add some improvements here :)
    Another problem is the pace of work, which is mainly due to the rigidity of the machine and the spindle used :)

    Can MPCNC be recommended and is it worth investing?such money into a "toy"? At the moment, it is difficult for me to judge due to the lack of time to test the machine, at the moment it looks promising for amateur and hobby applications :)
    The only test I was able to do was the crown engraving (done with a 6mm cutter, I had no other :) )

    MPCNC - a printed CNC milling machine!


    I was quite positively surprised that I didn't improve the machine, I just plugged everything in and let the milling go :)

    In my spare time, I start milling aluminum, we'll see how he can handle it :)

    The software I use is AutoCad, NX, Fusion360 and EstlCam.

    If I did not write something, please let me know, I will be happy to answer questions and any comments, criticism is welcome :)

    Cool! Ranking DIY
    Can you write similar article? Send message to me and you will get SD card 64GB.
    About Author
    Mrxnnx
    Level 8  
    Offline 
    Mrxnnx wrote 58 posts with rating 81, helped 0 times. Live in city Warszawa. Been with us since 2018 year.
  • #2
    Slawek K.
    Level 33  
    The stripes disqualify this design from precision milling due to the complete lack of stiffness, unless someone is satisfied with the tolerance measured in mm, and several ;)
    For the fun and satisfaction of building, it is only expensive fun ;)
    Out of curiosity, I redoed a similar project, only for me the working area was 2000x400mm because I needed to mill decorative boards for an old house. Somehow it worked out, but it was difficult to find two identical shapes :D
    As a result, I turned into trapezoidal screws instead of straps and it was much better ;)

    There are many projects of this type on http://thingiverse.com, but you have to be careful because there are several versions, and hello is for pipes with inch diameters ;)

    Greetings
  • #3
    szymon122
    Level 38  
    How does this spindle work?
    Will you provide his model?
    Slawek K. wrote:
    As a result, I turned into trapezoidal screws instead of straps and it was much better

    I am of this opinion too. I have an identically made laser plotter and after running the same pattern twice, you can see the shift. And you know - the laser does not touch the material, so there is no resistance. I wonder how it is here.
  • #4
    Mrxnnx
    Level 8  
    The spindle is a Chinese that I had at hand, it's hard to say if it has a model, in the evening I will upload a link to the store where I used to buy it :) is doing well so far. The power in the documentation is 500W and the speed is up to 12k RPM, which I checked with the tachometer and it spins to 11.5k, so quite decent :) Trapezoidal screws! You're one hundred percent right, I don't know why I didn't even think about it :) not only more precisely, it is an additional stiffening, does anyone have any idea how to rebuild the machine for trapezoidal screws?
  • #5
    Januszs0
    Level 11  
    Hello
    Regarding the spindle, I bought this model over 6 years ago, if I remember correctly 400W. During this time, the spindle in my amateur machine worked about 400 hours and never caused any problems. I process plastics the most. For rough machining, I use 6mm cutters with a depth of 0.6 to 1mm and in my opinion, even more could be taken because the spindle can handle such parameters well. I made aluminum with trim 0.1 to 0.2 and there were also no problems. My machine lacks stiffness, so I cannot judge the maximum parameters that can be squeezed out of this spindle. I used to measure the runout at the beginning and on the ground ejector, about 10cm long and 6mm in diameter, the runout at the end of the ejector was below 0.05mm. I use a power supply for power supply that allows the consumption of up to 20A of current. My voltage is a bit too low, because it is about 25V, so the spindle cannot work at maximum speed. If I had to change something, only a power supply for such regulated from 20 to 48V. An additional advantage is the quiet operation of the spindle. In my opinion, it is an ideal spindle for small machines because it is cheap and works well.
    Regards Janusz
  • #6
    Piottr242
    Level 21  
    What is the tolerance of this device? What is the minimum thickness of the cutter (it is important for rectangular holes)?
    Is it accurate enough that it can be used for milling, for example, the front wall of the housing for a device?
  • #7
    Fixxxer1
    Level 15  
    My MPCNC version:
    MPCNC - a printed CNC milling machine!

    The dimensions are 60x60cm, but with this construction the working area is very smaller, it is about 25x30cm if I remember correctly. Built mainly because I wanted to test myself, because I haven't done anything concrete on it yet. You can print cable guides, some handles and you can start having fun.
    I bought a Makita instead of a Chinese spindle, because it is sometimes useful for manual milling.
  • #8
    Mrxnnx
    Level 8  
    Fixxxer1 wrote:

    The dimensions are 60x60cm, but with this construction the working area is very smaller, it is about 25x30cm if I remember correctly. Built mainly because I wanted to test myself, because I haven't done anything concrete on it yet. You can print cable guides, some handles and you can start having fun.
    .


    For me, the external dimensions are about 100x75cm, i.e. the working area is about 70x50cm :) I recommend buying cable guides in China, a meter costs about PLN 15, so I do not know whether PLA or what you want to print there will be more expensive :)

    Added after 4 [minutes]:

    Piottr242 wrote:
    What is the tolerance of this device? What is the minimum thickness of the cutter (it is important for rectangular holes)?
    Is it accurate enough that it can be used for milling, for example, the front wall of the housing for a device?


    The thickness of the cutter depends on the shank in the spindle, the smallest shank I have is 1.5mm. At the moment, it is difficult for me to determine the tolerance, it is suitable for milling housings, just look at the elements that are milled by other users of these machines :)
  • #9
    oskar777

    Level 26  
    Quote:
    The stripes disqualify this design from precision milling due to the complete lack of stiffness
    Slawek K. on YT you have homemade 3D dukarki milling PCBs for LQFP and everything on strips.
    Stiffness is a problem, but you can get good precision.
  • #10
    Slawek K.
    Level 33  
    If there is no stiffness, then there is no precision, it goes straight hand in hand.

    Greetings
  • #11
    MarcinwqPL
    Level 1  
    What kind of pipes did you use? I can't find the right size. I only found such chrome tubes for hangers 25x1mm do you think it's enough? The working area is 1000x1000mm. It will serve as a home plasma cutter :D
  • #12
    Mrxnnx
    Level 8  
    I used pipes for hangers 25x1mm, it's not bad in general. The plasma cutter should be fine :)
  • #13
    emil
    Level 15  
    Hello.

    "- Bearings, probably 608RS 60 pieces, about PLN 60"

    Where does this number - 60 pcs - of bearings in this project come from?
  • #14
    Dariusz Goliński
    Level 22  
    Another question.
    What software do you use? I especially mean the cam.
  • #16
    Urgon
    Level 36  
    AVE ...

    I have such a spindle in my milling machine - it works efficiently and without problems. Before that, I managed to burn the 300W spindle, although I only cut 5mm plywood.

    I was thinking about doing the MPCNC, but it was the rigidity of the structure that made me questionable. I had a machine made of aluminum profiles with elements made on a 3D printer (the entire Z axis section) - it had problems with stiffness when cutting too fast or aggressive. Then I got a 3020T milling machine with a much stiffer structure as a gift, so I gave up MPCNC, although I do not exclude that I will do something like this or similar one day.

    As for the number of bearings, this design uses them everywhere, because it does not use standard guides and plain bearings in such machines.

    As for the software, I recommend Autodesk Fusion 360 with a free license for CAD / CAM. I control my machine by force with Mach3, but the previous one used a GRBL board, so I used bCNC to control it ...
  • #17
    Mrxnnx
    Level 8  
    emil wrote:
    Hello.

    "- Bearings, probably 608RS 60 pieces, about PLN 60"

    Where does this number - 60 pcs - of bearings in this project come from?


    This machine is based on the bearings, they are just used for smooth movement on the pipes, you just need to look at the design creator's website and see how the machine is broken :) the exact number of bearings is probably 53 pieces :)

    Added after 1 [minutes]:

    soft for machine control is a "marlin", which is popular in 3d printing, and when it comes to cam it is Fusion360 under a student license :) How can I, why should I not use it, I recommend it :)
  • #18
    Fixxxer1
    Level 15  
    I used tubes with a 2mm wall - despite the fact that I have a small working area, I preferred to add a bit and increase the stiffness.
  • #19
    drzasiek
    MCUs specialist
    Hi.
    For 1 set you can buy a milling machine from a Chinese on screws, on linear bearings, and with a driver.
    I don't know if this one is worthwhile.
    I have built 4 CNC milling machines and I know what the fun of building is, but I also know what the unpleasant surprise is that the device that was built is useless.
    Shortly after completing the construction, a man is fascinated that he has succeeded and tries to defend himself even against himself that what he has done is good.
    Then comes the time of verification and it turns out that it is weak or very weak.
    500w spindle and 6mm cutter? What cutter? (Material - cutting speed)
  • #20
    DmZ
    Level 18  
    drzasiek wrote:
    I don't know if this one is worthwhile.


    I have one, after modifications - it is not worth the effort, unless you are at the stage of learning. For me, of course, the milling machine turned out to be "too soft", but the number of "accidents" she experienced and their total cost in a large milling machine would be 5 times greater.

    I can sum up my adventure like this:
    + for learning and very light / undemanding / not very precise work - yes, yes.
    - if you want to do something meaningful (repetitive) and you have experience in cnc (and some expectations) it's not the way to go. The milling machine is very flexible, i.e. its parameters and accuracy depend on many factors - including the ambient temperature.