When one decides to build, or assemble in this case a CNC router, the electrical setup may be a bit of an afterthought. It’s very important, however, and a good electrical setup should give your project a nice finished look. More importantly, a good setup can help keep everything safe and avoid property damage. As I’m not an electrician, use your own judgement when building your setup. Rather than following what’s written here blindly, it’s a good idea to consult an actual electrician if you need some help.
All that being said, the first thing that looked for when wiring up my router was an electrical box to protect everything.
Industrial boxes are very good, but expensive. Fortunately, Home Depot carried an electrical box that was big enough for the power supply and the TB6560 router used to drive the servo motors. There wasn’t really a good way to fit the parallel cable through the small hole and clamp like I’d planned when I was going to use a USB to parallel adapter*. What I did instead is cut two slots into the top of the box with my manual mill. This allowed all wires to exit through the top and everything can be taken out easily when needed.
So besides the parallel cable and AC power line, four wires for each of the stepper motors had to be routed into the box. The wiring that came attached to the motors wouldn’t work, so I cut up and soldered several old serial cables to extend everything. The nice thing about this is that the wires could be matched up blue-blue, black-black, etc. So when wiring everything into the controller, one can use the actual motor wire colors and not have to remember which colors match up with everything. Before wiring it this way, make sure your surrogate wires can handle the current that will be going to the motors.
As for how to set up and wire everything to the TB6560 controller, this document should provide some instructions. Though not technically correct, I reversed some of the A and B coils to allow Mach 3 (See my review of this software) to control everything without switching things around in the software. I may switch it back, but for now this is my setup:
- X-axis – green, black, red, blue
- Y-axis – red, blue, green, black
- Z-axis – green, black, red, blue
You’ll also need a computer with a physical parallel port. Tigerdirect.com and probably quite a few other vendors sell remanufactured and off-lease computers that work quite well. Mach3’s requirements are quite low for a modern PC. I chose this one for $109 +S&H and it works flawlessly so far (update 11/15/2011: Not quite flawlessly, it decided not to boot up twice this summer, but after temporarily removing some RAM and letting it cool off, it’s worked well). There are some for even cheaper, but this one seemed like a good choice. It’s hard to believe that you can buy a PC for not much more than the control board that you’re using.
Once you have the basics wired up, you’ll need to route everything neatly so that it doesn’t look like a rat’s nest. For this, I would definitely recommend zip-ties. Below on the left, there’s a view of some of the wiring on the back of the router.
To the right, I mounted a surge suppressor with zip-ties. This allows for different accessories to be plugged in easily here. The computer is plugged into the wall directly. This allows the router to be turned off without turning the computer off. This is great if one needs to stop the router in an instant, or if wiring work needs to be done while the computer is still running.
One thing that needs to be thought of is wear on the wires that will be moving. Although it’s not corrected yet, on the view of the backside above in the top right corner, these wires will rub the back support. Filing the back at an angle should help some, but the wire will probably need to be wrapped to prevent wear.
Where the wiring is hooked up to the Z-axis motor and even the Dremel tool (here’s how I mounted the Dremel 200) will be twisted continuously when traveling in the X direction. To prevent this, I zip-tied these wires to the motor support. This should take stress off of the connection point in both these devices.
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*A USB to parallel port doesn’t work with this, btw.