CupCake CNC build, part 3: The electronics

3D Printing & Imaging Technology
CupCake CNC build, part 3: The electronics

It’s finally time to start building the CupCake CNC. The first thing you should do is read all the instructions. Don’t pass by the ‘mistakes to avoid section‘, it could save you some misery later.

Let’s get started with the CupCake electronics assembly. I ordered the deluxe kit from batch #8, so most of the electronics were already assembled. Yay! Not that soldering isn’t fun, but I’m happy to skip the soldering for this build and get to printing faster!

The stepper boards:


Not much to do here since the board is already soldered together. However, you do have to add the insulation-displacement connector (IDC) to the ribbon cables, and perform a simple test.


All you have to do is insert the ribbon cable into the plastic IDC connector and squeeze it closed. You might want to use some pliers to help snap the top down.


Take notice of the arrow on the connector. The brown wire is the index wire, and it should be directly above that arrow on both ends of the cable.


Rinse and repeat. You need to make three cables, each with an IDC connector on the end.


Let’s give the board a quick test. This is really important if you soldered together the boards. Mine came pre-assembled, so I’m not overly concerned. However, I will plug it in and make sure it receives power. I will be making a separate post about testing all the electronics. Check out the wiki for the full testing procedure.


To perform the simple power-up test, you only need to do a few things. First, make sure the power supply is unplugged, and selected to the proper voltage. I need it to be set to 115v.


Next, remove the 4-pin section of the large connector on the power supply. In the picture above, you can see the 24-pin connector on the left, and a smaller 20-pin connector on the right. The connector on the right is from a different power supply that I had, it’s just to show you the different sizes. The power supply that comes with the kit has a 20+4 connector. You should see a slight seam on the connector. Just grab it, and snap it off. It’s really easy.


Next, plug the 20-pin connector into the socket on the main motherboard. It only fits one way. Also, make sure the power switch is off. Next, plug one of the 4-pin power supply connectors into the stepper controller board. Finally, connect the IDC cable you made earlier.


Now you can go ahead and plug in the ATX power supply. Next, turn on the power switch on the motherboard. You should see a green light come on both boards. Again, if you soldered these boards by hand, I highly recommend you run some more tests as described on the wiki.

The Plastruder:


Again, mine came all assembled. I just took a quick picture and moved on. I’ll burn the bootloader later, as I think the IC comes blank. Burning the Bootloader isn’t difficult, but I want to make that a separate post since you may need to build the USBtinyISP kit.

The motherboard:

IMG_9285 2.JPG

Mine came all assembled. I’ll be burning all the Bootloaders in another post.

Building the endstops:


Not everything comes pre-soldered in the deluxe kit. You do have to make all six endstops. They go together really easily. Just remember to make four endstops using the RJ45 connectors, for the X axis and Z axis, and two endstops using the 3-pin connectors for the Y axis.


I added the (3) resistors, LED, and the plug in one step. Follow the instructions on the wiki for the exact resistor and LED placement. It’s easy.


Flip the board over and solder away. This is beginner-level soldering.


Next, you need to add the opto switch. It can only be inserted in one direction. Try to lineup the holes in the opto switch and the PCB. I used a couple of small screwdrivers to keep it aligned, then I bend the leads.


As you can see, it kept the holes perfectly aligned.


Rinse and repeat. Just remember to make two endstops using the 3-pin connectors and not the RJ45 connectors.


When you are all done, go ahead and plug the endstops into the stepper board. Power it up, and test it out. When you insert a piece of paper into the opto switch, the green light should come on.


It looks like everything is working so far. I still have to burn the Bootloaders on the boards. I’ll be covering that step in the next post.

Ask questions! Do you want to see a better picture of a particular part, a different camera angle, a video perhaps? Maybe you have a suggestion for a cool mod or hack? Let me know in the comments. I’ll try to answer them as best as I can. Thanks!

Build history:


    Having just arrived home from a quick trip to the hardware store, I was pleasantly surprised to see a large, unmarked, cardboard box sitting on my front steps. This isn’t an uncommon event, since I am constantly checking out cool products and projects for the Maker Shed, however this box was a bit larger than normal.

    Oh wow, it’s the CupCake CNC kit from MakerBot Industries! I’d ordered it weeks earlier and had completely forgotten about it. (The truth is out: I have an atrocious memory, sad but true.)


    And so the adventure begins! I’m going to document my “out of box experience” with a MakerBot. How many posts will the series be? I’m not sure since I’ve never built one. How often will I post about the build? Again, not sure, but I’ll try to do at least one a week, maybe more, it all depends on how much free time I have between all my other maker-ly projects.

    A little background: My CNC experiences


    I’ve been tinkering with CNC for about 10 years, and consider myself an enthusiast, not an expert. I do own a few CNC mills, routers, and lathes. I have retrofitted old mills, and even build one from scratch. Pictured above is my mobile CNC machine, dubbed the “MobileC.” I stuffed all the components into a mobile tool cart so I could bring it to hackerspaces, workshops, and events, all in the hopes of helping out fellow makers.


    The mill is a Sherline 5400 that I retrofitted for CNC. Also, I added a few extra parts to make it even more useful. It has a longer reach, thanks to the headstock spacer block on the column, and a larger table that I simply mounted to the stock table. It’s a sweet machine. I love my little Sherline!


    All the electronics are housed in the cart too! There is a 19″ LCD monitor, wireless keyboard and mouse, desktop computer, and CNC controller. It’s a tight fit, but it works perfectly. There is even an extra full-size drawer for tooling and accessories.


    I’m thinking of replacing the computer, keyboard, and mouse with an HP TouchSmart, but I have to save a few more pennies for that upgrade.

    Does anyone want to know more about my MobileC? Let me know in the comments. After I build my CupCake CNC, maybe I should do a series of articles on CNC machining?


    I purchased the CupCake CNC kit with my own hard-earned cash. I waited several weeks for it to arrive, just like everyone else that placed an order. No favors, no freebies! Why did I buy one? Well, for two reasons.

    • Reason #1 – I like what MakerBot Industries is doing for the open source community and open manufacturing, so I wanted to support them!
    • Reason #2 – I am going to document the build for Make: Online, and if I like it, I’ll let you know, and if I don’t… well, I’ll let you know that too! No biased reviews here.
    • Reason #3 – I am a CNC junkie, and I had to have it, even if my wife was questioning whether I really needed another machine in my studio! “Ha!” I said, “You can never have too many machines!” Oops, only two reasons, right?! :)

    Questions & suggestions:

    Ask questions! Do you want to see a better picture of a particular part, a different camera angle, a video perhaps? Maybe you have a suggestion for a cool mod or a hack? Let me know in the comments. I’ll try to answer all of them as best as I can. Thanks!

    Build history:

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