Tom's Mostly Printed CNC (MPCNC)

Tom's MPCNC

When finished, this is going to be a 3 axis CNC milling machine.  All the 3D printed parts and the metal bars are finished and this is the mock up assembly to make sure everything went together as expected, and so far so good.

What does it do?  Well, a CNC mill cuts material away from a blank, such as a block of wood, plastic, or aluminum, using precise movements in 3 dimensional space.  A spindle of some sort, such as a Dremel Tool or a router is mounted to the assembly in the center of the machine to drive cutting bits like drills and end mills and the machine moves this spindle left/right (x), forward/back (y), and up/down (z).  This is opposite from a 3D printer which adds material.  Both have undeniable value in the Maker's world.

Now the cool thing about this machine is that the spindle drive motor can be swapped out for a 3D print head, a laser, a hot knife (to cut foam) or a drag knife (to cut vinyl).  And since the machine minus my time to make it costs under $500, it is not out of the question to build several machines and dedicate each to these different tasks.

The software that runs this machine is either totally free or ridiculously cheap and worth every penny.  My design work will be done mostly with Autodesk's Fusion 360, which has a built-in CAM package to create the g code programs that tell the machine how to make the part.  Fusion 360 is FREE for students, hobbyists, and small start up companies.  If you are young and want to get into CNC or 3D printing, you need to learn this program.  There is no doubt in my mind that it is the future of 3D CAD/CAM.

I did not design this machine.  I have only printed the red and black pieces (GA Bulldog Colors!) on my 3D printer and cut the metal bars, which are made from 3/4" conduit.  The other parts and instructions are available on the designer's website vicious1.com.  I am really impressed by the design and how rigid the printed parts are.  I mean seriously, as I'm assembling it I'm thinking to myself, "I could never come up with something like this."  Well not yet anyhow.

The instructions have a calculator that gives you cut-lengths for the metal tubes based on the build area you specify.  The larger it is the less accurate it is.  The size of my build area is 20"x20"x5.5" (x,y,z).  The "z", or vertical travel is a little misleading because the build surface of the table I will make to go with this machine will drop down.  I have not decided how far, but probably 18.5" in half-inch increments giving me plenty of room to work on tall pieces.

The Dremel Mounted to the Z axis carriage.

For anything substantial in size or hard materials, the Dremel is simply insufficient.  It is just fine for testing and learning though.  I intend to eventually mount a spindle that allows CAM driven RPM control and significantly greater power.