Thunder Cats are GO!

A bunch of progress has been made since my last post. Two major steps have been achieved .

• Mounting the Gen3 boards
• Wiring the Electronics

Mounting the Electronics
This started with making a template by exporting the layers out of Eagle to a dxf file and then took that into my CAD program where created the board arrangement. I used some glue stick and pasted it to a piece of plywood and cut it to size.

I made some home made standoffs from drywall mollies. I used some washers to get the desired spacer length and cut them with some good size wire cutters.

Here is a driver board with the standoffs. Also you can see that I added the right angle headers for the opto endstops. I didn't bother taking out the CAT5 connectors.

I had a nice hefty bracket for mounting large curtain rods and  used it to mount the electronics board. I wanted to make sure that the electronics were off the bench so the machine does not take up so much room. All but the power supply is off the bench and I am working on getting that mounted some how.



Wiring the Electronics
Here are some notable points I had for the wiring:

• I unsoldered the molex connector pulling the pins out one at a time and soldered in screw terminals for hooking up the stepper motors.  Digikey: A98168-ND TERM BLOCK 4POS SIDE ENT 3.81MM
• I found some sprinkler wire at a home center to hook up the stepper motors. It worked out great. It is multicolor 18AWG solid core wires with 7 wires in the bundle and has black PVC sleeving.
• I wired up the opto couplers and with Red (+5V), Black (ground) and yellow(signal). This wire was connected to 0.1" female connectors. (Digikey: S7001-ND CONN HEADER FEMALE 3POS .1" TIN) on both ends. 
• I used right angle 0.1" spaced header pins on the driver boards that are right underneath the cat 5 connectors. I didn’t bother to remove the cat5 connectors since they were not in the way.

At this point the McWire is completely wired and ready for action. The next steps are firmware installs, softwares and then printing!

McWire and Opto-Endstops

So I didn't have as much build time yesterday as I normally do but did manage to get the opto-endstops built and mounted. These came along with the GEN3 electronincs that I got from MakerBot. At first, when I poured the contents of the bag O opto-endstops out, it looked like I was in for a bunch of work.

I called up the link that was on the outside of the bag that had the assembly instructions and no problems with assembly except inserting the 5 leads of the optical sensor into the hole. Lining up all 5 spindly leads at the same time was a challenge for me so I trimmed each of the leads at a different length so that they would go in one at a time.

I stuffed and soldered in all of the components except for the connector which I left unsoldered. I wanted to do a fit check at each of the locations before committing to having it on the board. It's a good thing I did because it would have definitely interfered with the Z motor shaft. Given that I decided to go with a right angle header solution.  This option was smartly designed in so it was easy.

After the boards were fully soldered I tested them using the Arduino board I got from Adafruit Industries.  It was a simple cut and paste of the code from the MakerBot sight and the program was running on the board. I did have one problem while testing. At first it didn't work. I checked all my wiring and hookups and made sure that the board had power and ground.  I thought, ok I'll just move on to the next one and get back to this one. Well, none of them worked! Then I was suspicious. I noticed in the photo on the assembly and test web paged used a thick piece of  cardboard so I changed the piece of white printer paper I was using to a piece of cardboard and it worked. In fact now all tested good. I then colored the piece of paper black with a marker and tried that. That seemed to do the trick as well.

Once the boards were working, I started mounting them to the McWire.  Some location were fine and some were iffy. I think I will end up moving one or two of them. I will see as the build progresses.  The one closest to the Z motor had the highest probability of interference.