This is a short blog post documenting the final stages of my custom CNC router project. The main design and construction of this machine was completed in roughly 6 months and the youtube clip below shows some of the first movements I got from the machine.
I am running the machine with Mach 3 control software via the Ethernet SmoothStepper (ESS) board and Gecko G540 4-axis Stepper driver. I highly recommend the ESS board as it allows you to outsource the stepper pulse stream computation to a dedicated processor, rather than the traditional setup where pulses are output directly from the computer via parallel port. By negating the need for an archaic parallel port it also allows the whole machine to be run directly from my laptop via ethernet cable. I’m also using an Xbox controller as a remote control for the machine, this greatly aids my job setup process and is made possible by a plugin which is available from the Newfangled Solutions under the plugins page.
The video below shows a basic helical milling sequence which is cutting a grid of holes that will be used for workpiece fixturing.
The MDF bed was then removed and M8 threaded t-nuts inserted from the underside.
I have pre-cut 4-6mm MDF sheet with a grid of holes in the same arrangement as my bed, this allows me to bolt clamps and fixtures through the sacrificial sheet without having to cut the MDF to the exact size of each job. This sacrificial layer ensures a clean cut through my workpiece without damaging the machine bed.
- Cut Size: 850 mm x 550 mm (approx)
- 2.2 kW water cooled spindle
- 15 mm THK linear slides on all axes (X,Y,Z)
- 16 mm ballscrews on all axes (dual screws on Y axis)
- Nema 23 stepper motors
- Gecko G540 4-axis stepper driver
- Ethernet SmoothStepper Board
Although the machine is capable, I am yet to try any full 3D machining programs. I have run many 2D/2.5D CAM programs produced using ESTLCam, which is a surprisingly simple, functional and cheap (almost free) piece of software, which can be found at www.estlcam.com. Most of my projects so far have been in wood or Acetal, I plan on cutting 6061 aluminium plate with this machine and will dedicate a post to this topic at a later date.
If you would like to learn more about the design and development of this machine, the complete build log is on the CNC Zone Forum. If you haven’t already seen them, please also visit my website for the other posts in the DIY CNC Router Series.
In closing, I am very happy with how this machine turned out and have learnt a great deal along the way, which was one of the main goals of this project.
Update (October 2017): I have had quite a few requests for the CAD model of my machine, so I have made it available for download in Fusion 360 via this link. A small disclaimer, this is not a complete model, but has all the parts required to build the machine. It is also the first model which I built in SolidWorks, so may not have been modeled with best practices employed.