Putting it Together - Part 2

Starting with the Motor Driver

Now that I have the main gear, it is time to start putting it together. The first step is to setyp the motor driver board. I've decided to mount it at the bottom of the case using standard motherboard riser screws. I've also stripped out a parallel port cable (so it would fit more easily) and routed it to the board.

The next setp is to take out the wirng for each of the motors. The output of the board requires 4 wires per motor. I got some 16 guage cable (which is somewhat overkill but works well) and i've added a 6 pin molex connector to the end.

The board also provides direct access to the unused pins of the parallel port. These are generally intended to be used for limit switches and "emergency stop" buttons. So I have routed them in another set of cables (24 guague) in a set of three molex (3 pin) connectors). You can also see the red and white cables which are intended to connect to the power supply.

Setting Up the Motors

The next step is to rig the motots. The setup below looks a little complicated. This comes from the fact that the motors have eight wires but the controller board only uses four. Looking at the data sheets for the board and motors showed how to rig the wires so the eight wire motor could be treated as a four wire bipolar motor (which is what is prefered for the controller board). And at the end, there is a connector to it can be hooked to the output of the board.

Now, i've kept the cables short for now since I don't know the actual length I will need, I will essentially make a set of cables with appropriate connectors once the hardware is put in place on the actual mill so I can measure the real length needed.

There you go... The final setup ready for a test run. Notice the monitor on top. This is a small touchscreen monitor I got for another project that never got used and I figured it would be great for this project. So I mounted it on the top and ran the cables for it inside the case. Plus, since it runs off of 12V, I simply rigged it so it could pull it's power from the computer's power supply.

To test the motors, I will be using Mach 3, an inexpensive CNC Milling software that is commonly used. The big advantage is that it comes with a full featured trial (which is only limited by the complexity of the milling programs it can run). So let's see...

Problems... Problems... Problems...

Well poor planning 101 has just occured. Once I got everything ready to go this is where i've started encountering some problems.

The first problem is with the touchscreen monitor. It only supports 640x480, which would be fine except that Mach 3 is designed to run at at least twice that resolution. The monitor will let me increase the resolution but due to filtering, this makes the on-screen text almost unreadable. In addition, the touchscreen feature seems to be somewhat flakey, most likely a driver issue but it is certainly aggravating.

The second, and most important problem, is that the motors aren't turning!!! So I had to dig and make sure everything was connected properly. After some extensive diagnosis, the conclusion was that the controller board was not fully compatible with the type of motors I had and this is why they were not turning.

Solution?

For the monitor problem, I can of course use a regular monitor and mouse for now. This is not a huge deal, just "less cool" :)

For the motors, the company that makes the motors (Keling Inc) also has their own controller system. So I have decided to get rid of the other controller and upgrade to the ones provided by Keling. The next post will go over the changes I have to make for the new motor controller...