Here at Beatty Robotics, my daughters and I enjoy making robots. Of course, to make robots, you need good parts. We started out cobbling parts together from old stuff we had laying around, and of course we’ve purchased many components, but more and more, we wanted to make our own metal parts. We started out using hand tools and power tools (and we still use these), but it’s difficult to make precise parts, so we built a 3-axis CNC mill.
The components of the CNC include:
A custom computer and electronics enclosure that we built from aluminum and acrylic (and equiped with plenty of temperature sensors, a digital fan controller, and blue glowing fans!)
The innards of an LCD flat panel that we “liberated” from entrapment (better known as a case) and bolted to the wall.
What seems like miles of shielded cable protected in stainless steel sheathing.
A 220 volt, 3-phase Variable Frequency Drive (VFD)(gray box bolted to wall above) that powers the CNC’s main spindle
A 1.5kw water-cooled, high-speed / high-precision spindle (24,000 RPM).
A 24″ aluminum cooling tower (just below the VFD)
A 3-axis gantry system driven by Stepper Motors and precision ball screws
A large, T-Slot work table with acrylic sides for chip containment
Emergency Stop button box (front with red button) and manual control dongle (black)
It took a long time to put it all together and get it all working, but it’s been a labor of love and one of our favorite projects so far. We’ve provided some more pictures below, as well as some of our first test parts to see what we could do with it.
We designed and built this custom computer and controller box, including a custom enclosure. This box contains the motherboard, SSD hard drive, memory, fans, power supply, fan controller, stepper motor drivers, and all the other components of the CNC control system. We mounted it on the wall behind the CNC itself.
Machining a sign plate: From left to right: The CAD drawing displayed on SolidWorks CAD station, the CNC computer/controller (the blue glowing box), the CNC screen, the VFD spindle controller (with red digital read out), the cooling tower, and the CNC itself (on the right) with the part being machined.
One of our first CNC projects was to mill this interesting abstract pattern into a solid block of aluminum. This pattern is known as a Turner’s Cube.
Apprentice Machinist #1
A close up of our Turner’s Cube. It’s not perfect, but it was a good start!
Our very first CNC project was to cut, drill, and engrave this top plate for this techno-steampunk tank.
A plaque in honor of our dog that had passed away
A base plate with a hole pattern (for the Telegraph project we’re working on). We machined one out of copper and one out of brass.
The custom cherry center console machined on the CNC for an electric car.
We ran into a particular challenge when it came time to build the mast. In the end, we decided to design and machine a custom servo plate using the CNC. The top of the plate will hold the pan servo. The bottom of the plate will hold the shaft tube (using a circular slot).
In this picture, you can see that the fan control system displays the rpm speed of each fan and allows you to adjust it. It also displays the temperature of the corresponding sensor. We’ve attached the sensors of the microprocessor heat sink, the RAM, and the other critical components.
The CNC required extensive electronics, wiring, and soldering
When we were building the CNC we often joked that it would have been convenient to have a CNC to build our CNC. It’s hard to be precise without one. One of the techniques we used was to print out cutting and drilling patterns on our laser printer, tape it to the aluminum plate, then do the necessary work.
One of the sub-systems of the CNC partially assembled.
Building the CNC required extensive planning, but there was also a lot of trial and error. We tried three stepper motor controllers before we found the right one that worked perfectly for our needs. We also tried three different spindles before we found the right solution, which was a 3-phase, 220 volt, 1.5 kilowatt, 24,000 rpm water-cooled spindle. We love it.