I'm building a CNC mill out of parts from a building set called Actobotics. This set (or product line) is great for building robots, enclosures, and other projects. I'm hoping I can use it to make a cool CNC with a 4" bed, mainly for making PCBs.
After several months, I picked this project up again. So yeah, I'm building a CNC mini mill. The sort of thing you could engrave a circuit board or something like that. I'm building it out of the very excellent Actobotics building system.
However, this February I got a very cool but brain-exhausting job that sort of derailed the project. I was able to scrounge enough brain cycles to take this up again--thanks in part to Actobotics for sending me some more parts!
So, my original concept called for a much higher gantry, on par with the 3D printer that I own. It's built out of Makeblock beams, which are very cool in their own right. For instance, did you know that Makeblock parts have a hole spacing identical to Technic LEGO?
Despite the coolness of the beams, however, their 3D printer was not a successful product. It was a wobbly sumbitch, I gotta say. It's possible that 3D printers made from building sets simply have too many connection point to be solid. So for me to model my mill, which surely will have MORE stress put on the toolhead, on same uber-high gantry, sounds like a fool's errand. I may need to get beams with more mass if I want to do any kind of precision milling--the Actobotics channels may simply lack the mass to asborb vibrations.
Then there is the infrastructure of a mill, much of which I lack and would have to buy. I need to get the actual rotary tool; I was going to start with a simple 12V drill motor with a chuck add-on. I still need limit switches, though I bet I could scrape some up in the basement. Still need CNC controller hardware and servo motor controllers. All of this makes me think that I'd like to simply take the Makeblock printer's old extruder and the electronics, and move them over to Actobotics chassis and forget the mill.
But would the Actobotics 3D printer be any more successful than the Makeblock one was? The #1 thing I felt I could do to reduce wobble was lower the Z-height to something fairly modest. What was the point of having a 6"-high build envelope if the damned thing is crooked? I can still do perfectly fine things with a shorter Z.
Another advantage to switching over to a 3D printer is that I work for a company that makes all sorts of flexible heaters, so building the perfect heated bed is totally a possibility.
The photo shows the new shorter gantry. The project continues!
Worked a little on the Y axis and gantry. I like it! It feels very solid. However, I do need to get the two Y-axis 8mm rods further away from the side channels. Another change is that the Y will be controlled by a stepper outside the main frame, with a 1/4" rod running through the whole width.