How to wire an arduino-based 3-axis CNC machine

Step 2 Wire the stepper motor to the EasyDriver

Now we'll wire up each of the EasyDrivers.

Remove some of the interior wire from the Cat5 and strip the ends.  For each servo you will need two normal pairs of white/colored and one oddball of a white and two colored.  In all, you'll have to strip 14 ends.

PCB soldering is easy, once you get used to it.  There are many other tutorials that cover the subjct.  Follow the image as indicated.  Your color combinations for the servo may be different.  I had to google for a long time to find this page with the color codes for my model.

TIP: "Do NOT connect or disconnect a motor while the driver is energized. This will cause permanent damage."  -- Sparkfun

Next we'll wire the power sources and the arduino.

Comments

[bac512]

I was just looking through an old printer to scavenge parts from, and I notice has 2 stepper motors, but only 1 stepper motor driver.. which got me to thinking, the CNC machines DONT operate MULTIPLE steppers at once, do they? don't they basically move all x, move y, then move z (or so other order, but, complete to the point). Would it cheaper/easier to build a switching circuit to switch the steppers in and out of the stepper driver, so you'd only need 1 driver, 1 arduino, and 1 switching circuit? and that circuit could probably easily handle 3, or even more for the really fancy machines?

[gunnk]

Not sure what kind of circuit you have in mind, but remember that you'll need to keep supplying power to each stepper at all times. Steppers only provide holding torque when powered, so you'll get all sorts of slip if you cut power to them (especially if your machine has any kind of rotating bit on it).

[bac512]

hmmm... ok, even more reason not do use only one driver :)

[willrandship]

Well, if you can keep it powered while switching, you might get away with it.

[aggrav8d]

You'd get less accuracy than running them all at once. If you move X and Y at the same time you get a diagonal line. If you move X and THEN Y you get a square shape. The difference is probably tiny. I say try it and let us know how it goes :)

[bac512]

thats true, I wasn't thinking things through completely. BUT, it COULD be useful in other things (robotics?) that used multiple steppers to make it cheaper. (again, yeah, less accuracy, but, for something that didn't need THAT MUCH accuracy....).....
yeah, unfortunately, i don't know enough about electronics to know how to design the circuit....

[90mp11]

The only problem with that approach is that you would quickly wear out a switching circuit, as it would have to switch hundreds of times to form a diagonal, or arc line, of which many projects are built.

I like the idea in essence, and for a 2.5 axis engraving machine, this would be ideal, but for a 3 axis, you'd be making more work for yourself, and creating more cost in the upkeep to keep replacing components that burn out on the switching circuit.

[aggrav8d]

transistors and resistors are your friend. Look at http://www.youtube.com/watch?v=Fc3R1SP5Ykw for a simple example of how to design the circuit you want. Since the NEMA17 steppers are 12v, you don't have to change much.

[cdxanti]

Correct me if I'm wrong but I can run my 3v 4amp stepper motor using this board without blowing the arduino or the chip?

[aggrav8d]

The power to run the stepper is separate from the power to run the chip & the arduino. The stepper power runs THROUGH the chip because the chip controls the pulses. I do not know how high your amperage can go before you burn out the chip. I've seen people attach cooling systems to their chips. I know that at 12v/2a the chip is hot to the touch. Ask on the Sparkfun product page for more information, or try their forums. Post back here when you find out - I'd like to know what the upper limit is.