Cabinet and Work Surface

I forgot to post a couple pics earlier. This is the junction box for the limit switches. First the inside, the soldering isn't finished in this shot. The grounds still need to be joined and then the perf board pressed in and glued:

Here's the outside. Sorry about the focus. The light isn't great for photography and I'm a bit lazy with it.

After wiring up the controller I went crazy and rerouted the speed controller for the spindle motor. I also disconnected the thermal cutoff switch from the motor control and connected it to my microcontroller. Rather than shut the motor down it triggers an audible alarm.

Here's a before shot of the mill. The speed control is the box to the right of the spindle and below the motor. If you can figure out where those things are.

And here it is with the speed controller missing. This angle shows a significant improvement in visibility of the work area. Plus, the controls will be with all the others. I used a film canister as the junction box.

Earlier I posted someone else's cabinet for a mill-in-a-box. I thought I'd do something similar. The box would serve to hold tools, keep dust off the machine, and protect it from swinging 2x4's. But then I started making measurements and realized the part of the cabinet above the work surface was going to be huge, a 24" cube. That's going to be heavy. I got a bit concerned about my ability to build something sturdy enough to handle the weight. Then I called a contractor buddy of mine to see if he had a source for scrap counter top. It just so happened he was doing a kitchen job later in the week and pulling out a Corian solid-surface counter top. I pulled this piece out of his dump trailer:

It's a neutral grey, kind of speckled like granite but nothing warm and flowery. Not that there's anything wrong with that. Just not what I want in my shop. This piece is 30" wide and 25" deep. It even has a backsplash. I was going to build a worksurface 24" x 24" so this is a little bigger. But with the mill sitting on it, it doesn't look that too big (the work surface). The white card stock in the foreground are stand-ins for my controls. I've even got room for the DRO.

So I think I'm going to bail on "enclosing" it. I can always add that later. This material may be a bit hard to work. I've got to drill a number of large holes and cut out rectangles for the DRO and throttle. I'll take my time, hopefully won't screw it up.

PCB Wiring Complete

I've completed the wiring for the new controller board. It's not pretty, but it's going to be hidden anyway. The important thing is that the connections are good and robust (they won't pull apart). A lot of the work was soldering connectors on the wires. Here's a shot of one such (male) connector:

There are 2 pairs of protrusions on the right for crimping the wire with. The right-most pair tends to get caught going into the housing, so since I was soldering I clipped it off:

 

Here's a shot of it soldered:

Most of the connectors I did were female. Occasionally I'd hit it with a little too much heat and solder and it would wick up the connector leaving enough solder in the channel to block the male connector. All in all it went just fine. Here's a shot of the new rats nest. It actually looks better than the prototype:

And a close up. It's not as well organized as I'd like but it's pretty good.

I did make a mistake in the design, though. The Sanguino has 2 pairs of serial lines. The actual port I use to connect to the computer is doubled by pins 8 and 9. Pins 10 and 11 are the other set of Rx/Tx lines. I wired all the lights to pins 8-13. This means 2 of my lights did not work since they were connected to the primary serial port lines (they flashed when I uploaded the firmware). Pins 8 and 9 are clearly labeled as Rx/Tx. Pins 10 and 11 are labeled as Rx2/Tx2 but the letters are very small and hard to make out. I must have been thinking that the clearly-labeled RxTx was the secondary serial port and since I'm not using it I could use it for lights.

I was smart enough to pull out all pins to the Sanguino. Pin 7 was designated as an extra output pin and pin 14 was designated as the piezo buzzer (alarm). Pin 14 was selected because it's a PWM-capable line (and it was at the end of the row after the lights). So I've re-routed 8 and 9 to 7 and 14. I moved the buzzer over to one of the extra A/D lines. What I've lost is the ability to use PWM to drive the alarm which would have supported multiple tones. Now I'll have just on and off. The alarm will sound when the mill motor overheats which should never happen, so I think I can live with a simple alarm sound.

PCB Assembled

I week delay due to vacation. I admit a Disney cruise is more fun than building robots. As soon as I got back I soldered the components on the board, cleaned it up and tested it.

Here it is with everything soldered on:

And with the components plugged in:

The DB-25 plugs in (via cable) to the stepper driver box. I plugged it in and tested it. The lights and buttons aren't connected, so I used a couple of test leads to turn on the limit pin and then tag the button pins. After some tweaks to the firmware to support a different arrangement of pins for the stepper motors the mill moved just fine in manual and program mode.

The next step is to make some cables and connectors for the controls. I need to give some serious thought to the cabinet and control panel layout so I can make wires and such the right length. I'm imagining an arcade-like cabinet to go with my arcade buttons and throttle controller. Not sure I can pull that off since I need to support a mill with open access.

Here's a cabinet I like for the top part:

I'd like all the features of the above. I need to figure out how I'm going to integrate the controls into this. Under the work surface will be a shelf or two for the electronics, the stepper controller box, transformer, power strip / surge protector, etc. I'll probably use the very bottom for material storage. I'll probably make it out of MDF. I want it to look cool but I want it easy to build. I'll use biscuits for joining instead of dados, rabbets, etc.

One feature I want not shown above, I hope to add some rigidity to the Z column. I need to design a spine in the center rear panel that can connect to the Z column. It has to be rigid of course, but I'd like it to double as a cable chase.

I might try to use Google Sketchup to design this. I have a lot of experience with 3D tools for animation and graphics. Sketchup has some very nice CAD features but has some concepts I'm not used to. I may end up with simple pencil sketch designs.