MFW June 2013 - Page 9

How the electrons flow If it is one thing that tends to overwhelm people, it is understanding electrical circuitry. And there is no shortage of it in a machine like this, so let me explain a couple of the basics. I have the machine computer in a standalone cabinet with the monitor, keyboard and mouse. From this cabinet we run a standard 25 pin printer cable to the machine. These 25 pin ports are a little rare these days as most printers are operated by USB, hence the reason I used an older computer with one of these ports already installed. It’s no big problem if you don’t have one though, as a card with one can be fitted to your computer and plugged into one of the PCI slots on the motherboard. They sell for about $30.00. I understand there are now adapters out there to allow you to run the machine via USB, but I have not had the opportunity to use one of these yet. The Breakout board This printer cable carries all of the information required to run the machine to an electronic board called the “breakout board”. This breakout board becomes the central interface for all of the machine systems. The drivers for the stepper motors, limit switches, emergency stop buttons and other input and output devices all run through this breakout board. It also provides protection to the computer of any return voltages, through the use of opto isolators. And it all operates at a very safe 5 volts provided from a DC plug pack type adapter. I use a plug pack which used to be a battery drill charger. From this board we run three wires to each motor driver unit, two wires to an emergency stop button and if you run limit switches, they all get connected together in series and run two wires back to the breakout board. There is an additional 48 volt power supply which connects directly to the stepper drivers to provide power to the motors. When you connect it all up it looks like a bit of a birds nest, but really it is pretty straight forward. The Homann designs website I mentioned earlier has some schematic diagrams of the hook up in their documents section whic ]\H]HXܚX[\[][ۋH\\[܈]\•\H]\[]\HH\H]\YXHو\]Z\Y[ ]YܙHH][] ]8&\]HH]]HYY]ˈH[[[ۈ\\[ܜ[\] KYܙY\\\ ܈Y[HZK \\[]][ۋYH]HH[܈ۛXYHX[[[ۈ]Hو^H L]\]][ۈH[^X\^\[ݙHH[X[\[Hو L\\܈YH]YH\H ][[ݙH [[H\\ [YHX^HH\H]\\[K\H]\[]]HHX[]H]\[YZXܛ\[ˈYH[X[ۈوX[]\ۈH]\][XX[H\[H[܈][\[]Y[XXو]ܛX[\\\[ K \\]][ۋ\[H[[XY[H\X[H\Y[\H\[Hو][ ][H][܈[ˈY[H\[[H\\]\]K]\][ۈX]\HH\]\[ۛHݚYHH[\]H\Z[YY ]XY\H[[[XوX\]H[H[\\\[H[][]XXH[\\XYH[[[^]\]H [HLXݙNY۝ܛ][\YH^X^H܈H] ][[X[\[\HX^[][HZ[[ ^Y][ۂ]\ؘXH][[H[Y[X]܈ˈ[\و\\XHH[YHۜX[ۈ\وHXX[H][H]H[]X[[[H\H\\܈]H[H[H[\ˈY[YH۝XYH]]X\K˛܈ H L ͈܈ M M