Movable Bed CNC machine 3

During my experimentation, I somehow made costly mistake(s) and found that the parallel port installed at my computer was not working properly after one initial successful testing. Subsequent testing were failures. I did not know why and when it occurred. I suspected it could be because my input power voltage supply was too high. I did notice some

flash over sparking at the easy driver stepper motor board. It could also be because sometimes I plug in and plug out the parallel port while the computer was running.

I tried to check this out using software like parmon running on Windows and also parallel port tester running on Linux and the result was not encouraging.

Later on, after much research on the internet, I found out that I needed a breakout board installed in between the computer and the output devices in order to prevent transient reverse flow of current of the output devices from damaging the computer. I found out that for severe cases, even the computer motherboard can be damaged.

The breakout board somehow isolates by using opto-couplers in between the input and output instead of using pure electrical connections. Electrical signals were converted to light signals at the input and then later converted back to electrical signals as in the original signal at the output.

So my stepper motor driver was burnt, and my parallel port was not functioning.

Luckily, my computer mother board was still intact.

So I searched Ebay and chose several pieces of EasyDriver stepper motor driver boards and a suitable breakout board. I also bought a Utility PCI to 1-Port 25 pin DB25 card adaptor to replace the original parallel port in my computer. Then I had to stop all activities for a while while patiently waiting for the goods to arrive. At the same time I had to get a parallel port wire with male/female connections in order to connect the breakout board to the computer.

Eventually, all the items arrived. Some took almost 5 weeks. Still, I was pretty busy with other activities.

Well, this week I did have some free time to work on the project. I managed to pick up an old fiberboard and did some drilling so that I can arrange all the components required for the electrical control system in a more pleasing way.

Although I only needed 3 stepper motor drivers at this time, I made some spaces for another additional 2 boards, since my breakout board have the capability to accommodate 5 axis.

The challenge was to connect and test without burning up any boards. Keeping fingers crossed, I cautiously switched on the power when the time came to test.

And it worked! Thank God! My first test with one stepper motor was successful.

My next test was with two stepper motors.

My next video will show me testing three stepper motors which could be assembled into a normal 3-Axes CNC Machine.