Step 4: TESTING..1..2..3
Don't be nervus. It's just a little electricity. First off it would be good to load up the KCAM (or what ever you plan on using) in your computor. Then when you feel comfortable that all the parts are in the right place plug the parallel port connector into the driver board(as shown below) and put a low wattage build in the socket for the motor. In this case I'm using middle, the Y axis driver.
For power I like to use one if these universal power adapters with selectable voltage output. They're cheap and they don't put out a lot of current so if something goes wrong it's less likely to damage your circuit. Set the voltage low and see if you have some vlotage on the power pins(16) of the CD4516 and the CD4028. If you don't have a volt meter just take an LED and tie a 10K(BRN,BLK,ORN) resistor to the positive(the long leg) and wire to ground tied to the negative(the short leg). Now you can use this as a probe to see where you have voltage. It will be very dim but we don't want to draw too much current away from the circuit.
Now go into the computer program and find the Setup Table. Set the steps per inch to 1000. Then open the CNC control and set the single step for .001 inch and activate the single step mode. Now each time you click the yellow arrows (up and down for the Y axis) the computor will output one pulse to the stepper motor driver circuit.
Put your LED probe on pin 10 of the CD4516. This is the up down input. When you click the up arrow the input will be low(LED off) and when you click the down arrow the input will be high(LED on). Pin 15 is the step input you will see a very short blink each time you click a n up or down arrow on this pin. Pin 6 is the Q1 output. It will change state(high/low) each time you click an arrow. And Pin 11 is the Q2 output. It will change state every other time you click an arrow.
On the output side of things we should see some activity on the CD4028 chip. Putting your probe on any of the output pins 1,4,6,or 7. These outputs drive the FETs. You should see the output go high every 4th time you click the up or down arrow.
If this all makes sense so far it's time to get the motor running. The common wire or wires of the motor which are the center tap of the windings should be connected to the light bulb. The other four wires should go to the four FETs on the circuit. If you are really lucky you will get the combination just right in the first couple of trys. Other wise just keep switching the wires arround until the motor steps in the same direction each time you click the arrows.
Watch the video in the next step. It may give you a better idea what to do.