Mostly Printed CNC (MP-CNC)

Having a CNC machine to cut panels for projects has been a wish for a while. Then I found this awesome project: Mostly Printed CNC ( As the name says, most parts are 3D printed and the non-printed parts are easily accessible. The controller is a RAMPs 1.4 board with Arduino Mega, easy to find cheap online. I used the Marlin firmware because it’s the same as both my 3D printers.

After destroying my Mendel i2 trying a new printing surface I had spent many hours printing the parts on my Solidoodle2 with a printing volume 6″ x 6″ x 6″. It took longer than usual due to my choice of ABS over PLA. I have had to reprint most of the parts in PLA. The project page gives accurate build times for each part, but it will vary depending on your preferred settings and printer. The total suggested time is 120hrs.

The bed size was determined by the largest piece of flat plywood I could fit in the car ~1000mm x 1200mm. For the X and Y axis bars I used 25mm curtain rod at about 1.#mm thick (thinner than recommended) Seems strong enough with minimal to no flexing. The original size of was 900x900mm (the standard size curtain rod). This allows for a build area of about 600X600mm.

Note: I built the CNC table the wrong way, it should have been measured and built from legs up, rather than from flat table down.

The tool that I chose to mount in the CNC is a cheap laminate trimmer ($35). The other options were a rotary tool with a snake attachment, or a larger plunge router I’d forgotten I had. It also worked out well when I found a pre designed mount, originally for a Ryobi router that looks very similar.

I used some cable ties to make a dirty pen attachment.

The first panels I made were part of a Prusa i3 kit (10mm version). It’s hard to see in the photos, but it’s actually 20% too small – I hadn’t changed the steps in the firmware. Use: DEFAULT_AXIS_STEPS_PER_UNIT   {100,100,2560.00,760*1.1}. You must do a reset in Repetier-Host after the cutter bit is aligned to your home position, unless you are using endstops.

Next was a carving. Carving is cutting lines that go deeper depending on thickness, and usually tapper up towards a point. the first photo was done with a flat endmill, then it’s cleaned by lite hand sanding. The last photo is a comparision of a flat and ‘V’ bit. The V bit looks better with the font selected IMHO.

Now a different material: 10mm acrylic. It cuts very well and can be de-burred using a sharp hobby knife.

I did change the size of the build area. When looking at plans I wanted to cut, most had a long side longer than 70cm. By extending the Y axis the total length of the table, it now has a build area of about 900x600mm. The second change to the table is to help with the dust and noise. By raising the sides and covering the top, the noise outside of the shed is reduced to a loud fan or very quiet vacuum cleaner – far more acceptable for long cuts and more neighbour friendly.

Firmware: Final_MPCNC_Router. (International Edition, M8 lead screw).

Upcoming mods:

  • Cable chains – cable chains for the axis cables.
  • USB camera and LED light – These will make it easier to monitor the long jobs without needing to open the lid.

UPDATE (a few months ago)

changed the center, corner, and rollers to new style to increase the rigidity and square it up easier

With the new center I tried some 3D milling of the classic Mortal Kombat logo:



15 thoughts on “Mostly Printed CNC (MP-CNC)

  1. Hi,
    I’m having a heck of a time getting my MPCNC to run with the ramps. Any suggestions? I used the parts listed in the mostly printed cnc site and have a 12 volt system. Added the changes to the marlin firmware and I can only get the motors to make noise. I set the stepper controller pots to 1 volt and raise and lowered them to have no success. Any sites you could point me to for some help? I’m wanting to use the mill to make wood signs. It would be much appreciated. Thanks, Cory

    • Hi Cory, during setup I had to adjust the pots as well. More voltage gave the steppers more torque. I noticed that if I got a little greedy/ambitious and turned the pots too high the motors would also make a vibrating noise but not actually move. When you started adjusting them did you turn them all the way down, and work you way up? What stepper motor drivers did you use? What are you using as a 12v power source and how many amps is it rated for? I’m using an old PC PSU @ around 15amps.

  2. I’m using a 12volt 5 amp power brick 8825 stepper drivers. I set my pots to .7 volts. Here is the link to my stepper drivers.

    And my stepper motors.

    I put a post forum post on mpcnc today. The site went down today looks like it being updated. Let me know what you think about the motor and stepper drivers? Thanks,

  3. Nice work.

    How did the small and large Ozito routers work? any issue and are you still using them?

    I ask as I am about ready to assemble my MP-CNC table, (I have the same 25mm chrome tubes from bunnings. but I am using the 900 and 1200 lengths). and I am looking for an in-expensive spindle.

    • Hi Randall, I only used the small Ozito laminator trimmer because I figured the other one may be too heavy for the size of frame I wanted. I’ve not had many issues, although you do need to make allowances for it – Eg; you have slow the movement while cutting; I use max 10mm/s, with 1mm – 0.5mm layer drops and you have to use good quality sharp bits.
      I also found the Z axis stepper would get very hot and fail to lift the router, so I added a heat sink to it and slowed the speed. That would occur usually when cutting channels.
      I have also updated it with the more rigid center which has helped with accuracy.
      Good Luck, and let me know how it goes.

        • Hi, I’m also using the Ozito laminate trimmer with my MPCNC and it’s worked fine so far using virtually the same limits you mentioned above. One thing I have noticed though is that the spindle spins ever so slightly off axis (about 0.5mm) which means cuts are slightly wider than expected. Hasn’t really caused any other problems but took me a while to figure out why cuts were wider than anticipated, particularly with a v cutter.

          • Hi, I also had slight movement when getting the trimmer to cut too much at once. the torque would twist the mount so it would look like it was being dragged rather than straight up and down. The new rigid center fixed that for me.
            I also had issues where the X and Y axis weren’t at right angles, which again I fixed with the different center.

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