Here is how to connect your router to the parallel breakout board through the on-board relay. You will need a spare extension cord. You will need to remove a portion of the outer jacket of the extension cord to expose the white, black and green wires (white = neutral, black = live and green = ground), understanding that the neutral and live create the completed circuit.

See this image of a similar connection. The terminal has the same connections.
https://www.buildyourcnc.com/images/vacuum-pressure-controller-relay-terminals-700.JPG

Image of the relay terminal:
https://www.buildyourcnc.com/images/breakoutboardrelayNONC.PNG

The live/black wire would be cut and one end of the cut would be secured into the P terminal and the other cut end would be secured into the S terminal. The live and ground wire would be uncut and travel from the plug to the router.


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You can also connect other high powered devices to the breakout board using any of the output terminals. You will need to supply extra relays like the one shown here:
https://www.buildyourcnc.com/item/electronicsAndMotors-breakout-Relays-relay-board-250V-12A-5V

Or you can find SSRs (Solid State Relays) that will accept 5v to drive the relay coil. Make sure the SSR will protect the 5V line from Back EMF as there is a coil in the relay. The one we sell contains a fly-back diode to protect the 5v terminal.

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I have your breakout board with relay parallel port , I have a vacuum, light on router and air pump I want to also hook up to board, can I hook those up to board and also could I had reylays to each one, what is the best way to figure this out any information would be great. Thanks

Have you tried a different input pin?

Customer response:
I've tried all pins: 10, 11, 12, and 13. I get the same non-response in each case.

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There may be a problem with the board. If you are using our parallel breakout board, we can ship you a replacement (call us), otherwise, you will need to determine the problem with the vendor of the breakout board you are using.

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I have tried 3 different breakout boards from 3 different providers and they all do the same thing My limit switches are microswitches wired NC with each axis wired to the BO Board. I have checked each circuit and all is OK to the BO board. each circuit has continuity at the board and when any switch is pressed the circuit breaks. Mach 3 does not recognise that the switches are even there. They are configured as active low Do you have a suggestion.

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I'm having trouble getting Mach3 to recognize my limit switches. I've eliminated everything back to the breakout board. I can directly connect Input 10 to GND on the breakout board while Mach3 is in autorecognize mode and Mach3 doesn't acknowledge anything.

Sure, the USB interface has a place for 4 axes of limit switches.

Each axis can have two limit switches: one for the ++ (positive) end and one for the -- (negative) end. The positive end would be the limit switch at the end of the machine that, say the machine has a 4'x8' area, reaches a bit after the 8 foot mark. The negative end would be the limit switch behind the 0 foot location behind the origin. If the origin is in the middle, the negative would be at a little more than the -4 foot end and the positive would be at a bit more than the +4 foot end. Note that you can have more than one switch on each pin where the NC is connected in serial fashion and the NO is connected in parallel fashion (this can be seen on the diagram in the multiple limits switch section). The software configurations for the limits switches are under File -> Settings -> Limit.

A typical limit switch has three connections on it. These connections consist of COM (common), NC (normally closed) and NO (normally open). The COM would generally go to GND and the NC or the NO would go to the pin. If the NC is used, then the the switch is constantly connected until the switch is pushed (engaged) then the connection from the pin to gnd is broken (open). Use the settings in software to set whether in NC or NO configuration.

Let me know if this information was helpful (or not) by adding information to this question. Thanks.

User response:
Thank you very much for this helpful information. I'm still a little fuzzy on how the 6 limit switches physically connect to each other and to the USB breakout board. You've stated one switch (home) goes to positive and another switch (limit) goes to negative. Are all the GND prongs from all 6 switches connected to each other and going to GND on the breakout board, or no? And the NC prongs, how exactly are they connected to each other? And to the board? There has to be a diagram somewhere shows this visually, no? I don't know how to wire the switches in series or in parallel. I have already physically installed all the switches on the machine and ran the wires to where the board is. Now I just need to know where to plug these wires into the board. Also, taking into consideration that I'm using the Planet CNC software, the only settings I have pertaining to limit switches is "Enable/Disable" for each axis, and the actual limit for each axis. Nothing about NC or NO. Is that only in Mach3?
Thank you.

buildyourcnc response:
On the USB interface, the COM on the switch connects to GND and the NC or NO connects to the input pin (i.e. x++, y--, etc.)

Limit switch configuration is rather difficult to understand, especially with series and parallel. You can think of series as a single wire going from GND to the axis letter input terminal (i.e. X++ or X--). If the wire is broken, then the circuit is open (or the switch is engaged in a normally closed scenario). Normally closed is like an actual wire, and when engaged, the switch "opens" (breaks the wire). This is why we recommend in some systems that you can put many switches in series on a single pin. When one of the switches is engaged (breaking the connection) then the entire circuit of switches is broken and the machine stops.

In a parallel scenario, the state of the circuit is always broken until the one of the switches is engaged and the circuit is then closed or connected. The topology looks like a ladder. All the switches connect to both sides of the ladder and the switches are like the runs of the ladder (the horizontal bars that the feet are placed while climbing). Imagine all of the switches broken in this scenario (normally open). It would be like the ladder could be split in two, but if one of the ladder runs (switches) is closed by engaging it, then that run would connect both sides of the ladder and the two sides of the ladder would have a connection.

There is a diagram on the USB page of the various limit switch configurations. If you need more information (visual and/or otherwise), please let us know and we will immediately add that information to benefit everyone.

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I have nearly completed the CNC machine from the book, but I am using it with a USB breakout board, and have no idea how to wire the 6 limit switches to the board. I'm having difficulty following the diagram on the USB breakout board screen. Can someone please help me?

My apologies for not getting back to you. We always answer the phones during business hours, so I would try that first. Our emails on Monday generally is stacked up as we are closed during the weekend. We can try your g-code here. Please send the g-code to the techsupport@buildyourcnc.com email address and we will test the code to see if it works.

By the way, do you get movement on the planet-cnc UI screen?

Additional Information:
The program starts and runs normal. I have all the correct movement on the mill and the UI screen. Then one of two things happens. It either stops and resets all axis to zero in the middle of the part or it freezes in the middle of the part. When it freezes, it is not moving on the cnc or the UI screen. Sometimes after a freeze it will come up with an 'IO timeout error', but the only way to clear is to unplug USB and start over.
I will send my settings and g-code files over tonight. Please be sure to load my settings when running the g-code. No movement of the cnc is necessary as the controller will do these issues without power to any drives and just the USB board connected, on my board at least.

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I have a MK1 board that I just got running and I am having issues. Do you have an MK1 board at your shop that I can send you my G-Code to run? The freexing/zeroing in the middle of the program issue happens even with no step drives attached to the board.

The fact that you cannot move the motors with the keyboard serves as a clue to a couple possibilities.

- The software may not be communicating with parallel port. (One possibility may be that your step pins are not low active, or vice versa depending on your drivers).
- You may not be in the correct tab of Mach3. Make sure you are in the Program Run tab.
- The jog on/off button on the program run screen may not be lit (invoked).

This address below shows the complete troubleshooting for this type of situation. It will show how to test each pin at the parallel port at the back of the computer and everything else associated with correctly wiring the electronics.

https://buildyourcnc.com/CNCElectronicsandWiring.aspx




Additional Information:
6 axis robot with Mach3 Card 6 Axis Motion Controller

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I have a home built CNC running Mach 3. I have power to all the motors and the breakout board but no movement when running g-code. I cannot even manually move the motors with the arrow keys or page up and down. It also has an integrated 120v receptacle showing an open ground. I don't know if all this is related.

Dealing with our USB BoB, it is really similar to the MK1 board, but is also loosely based on their DIY board as well. We have not seen that much of jitters or jerks, that we have noticed here while fabricating and testing the boards. We have not heard that many issues dealing with the board about abnormalities in running, unless we have not been notified in regards to customers who have used them under continuous use.

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Its mentioned that your USB Breakout board is based on Planet-CNC's MK1 board. Planet-CNC on their forums mention that they've discontinued their MK1 because of a low buffer memory which caused jitters and jerks in the machine? Am I likely to face a similar problem with your board?

For safety's sake I would recommend a new board because they are inexpensive compared to the electronics that they support. Alternatively, it's possible that the one dead pin is a simple fix, such as a bad connection or solder joint; if you feel comfortable making those repairs then it could be worthwhile to check. Finally, if you are not using all the input pins, you could continue to operate the limit switch on pin 11 and hope for the best.

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I have a breakout board and it appears that the pin 12 connection has failed: when i move my limit switches to pin 11 they work; they don't work on pin 12. Do i need a new breakout board?

You may want to try using a ferrite core or an inductor in addition to the shielded cable. Also, make sure you are grounding the shield at both ends. Even though this is not high frequency, grounding the shield at both ends in a motor scenario may help. Also, try to reduce any parallel wire runs.

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[575] Hi, I plug HY 220v spindle on the board. It work, but the is a unstable frequency on the spindle. I put shielded wires from BOB to Inverter, and from Inverter to Spindle. But the problem still there. I read that I have to put a Analogue PWM, is that true, or I have problem with my wires... Thank you

It's Mach3 USB Interface Board, I forgot to mention that!

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I'm having an issue with the AVI PWM output on my board the PW low is about half the voltage of PW High, so if I use 5v I get 2.5 v on low or if I use 10v I get 5v on low? I traced the signal back with my Oscilloscope and found that I get a PW low of 0v on the base of what looks like a smd transistor opposite the DCM connector, do you think I have a got a faulty board?

That was one of our older models, which we did not have any specific ground pins on our board, they were not added and we currently updated our board to include them.

For the random triggers for the limits and e-stop, we recommend having these wired separate from any other wires (communication, power, etc), and we recommend shielded cable as well! These will be very sensitive to noise and any interference that might be present.

Our newer model Parallel BoB: https://buildyourcnc.com/item/electronicsAndMotors-parallel-breakout-relay

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on the parallel breakout board I have, there are two 5v inputs on the limit swith side and no ground label. https://www.dropbox.com/s/hxeojviveteqq2f/IMG_7947.jpeg?dl=0 I have used an external ground for now but I am getting random limit and e-stop triggers. please advise

Yes, the 5 axis breakout board is a very suitable replacement and also contains a relay for spindle/router control which is not on the C10 board.

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I have propably blown my C10 breakout board. This is no longer available in your parts list. Is the 5 Axis Breakout Board with Relay a suitable replacement?

Is the signal gnd on the laser power supply connected to a gnd on the breakout board? Do you hear a high pitched sound, like a TV set with an antenna getting interference, but with a high pitch?

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OUR FIRST ATTEMPTS WERE WITH THE PLANET-CNC SOFTWARE, GOING THROUGH USB BOB. NO PROBLEM GETTING X & Y AXIS TO MOVE BUT UNABLE GET ANY ACTIVITY ON Z AXIS. WE THEN INSTALLED MANUAL SWITCH BETWEEN 5V AND TL, JOY. DISCONNECTED BOB FROM TH, MOVED OVER TH TL STILL

Most motherboard do contain parallel ports, but the port connector may not be at the back (in the section where external connectors will be connected). Instead, the motherboard may contain an LPT ribbon connector on the actual face of the motherboard (usually along one of the edges). You will need a ribbon connector to a DB25 female connector.

If your motherboard does not contain an LPT header on the motherboard, you can purchase a parallel printer adapter that plugs into one of the PCI slots. The price of the adapter is very inexpensive and sometimes is actually less costly than the actual ribbon connector.

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As I am building my 20" x 24" laser engraver cutter, I notice that there is no parallel port on the onboard computer and I have the parallel breakout board any answers?

That will depend on the controller that was installed in the redFly. If the controller is a pokeys57CNC controller, you can use Mach 4 with that system.

You can add a 4th axis and an ATC (Automatic Tool Changer) with the redFly system.

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Does the Redfly that I bought with the GreenBull in 2016 work with Mach4? Also I want to add a 4th axis and a spindle with automatic tool changer. Will this work too or do I need a new control board? I bought my CNC with a longer Z travel, so I have plenty of room for these. Thanks!

We recommend checking the dip switch settings on your drivers, having the correct microstepping/amp settings along with the steps/unit will help the motors run as effective as possible.
This is a default parameter that we use while we test our motors:
Driver dip switch settings will be at a 1/16 microstepping and 2.7amp (11001100) for x/y-axis and the z-axis will be at 1/4 microstepping and 2.7amp (10101100).

In planet-cnc with increasing the motor speed, you will have to modify the settings in planet-cnc (File/settings/setup) you will modify the initial speed, maximum speed, and the acceleration.
X/Y-axis step/unit: 1422.22 initial speed:500 maximum speed:750 acceleration:25
Z-axis step/unit: 1600 initial speed:100 maximum speed:300 acceleration:25
The initial speed and maximum speed will have to be roughly tested and adjusted per application.
Make sure to adjust the JOG slide bard underneath the axis controls on screen to about 750, to compensate for your x/y-axis adjustments. If left alone the speed will max out at the default setting.

Here is a video tutorial to calculate the steps required depending on your mechanical linear motion components. (

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I bought Nema 24 motors and driver package with usb board. What do i need to have more speed? Cant even jog past 25 ipm without the motor stalling (not having enough torgue)

You can do raster and vector engraving on the greenBull laser/spindle combination. The methods of this process is not accomplished in the same way as the typical laser machines where CorelDRAW is used. The Mach3 laser plug-in can be used for the raster engraving and standard CNC g-code can be used for vector cutting and engraving.

The raster method will not be fast on the greenBull since the z-axis is heavy and there are inertial limitation on doing fast raster back and forth movement. Vector is the best use of this machine.

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I am looking at purchasing the greenbull 5X system with the laser/spindle combination. Can the laser do both rastered engraving as well as vectored cutting with the same breakout board and software? If I have this wrong please let me know what would be needed to accompish this.

Your steps per inch will vary. I suggest watching my calibration video.

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I AM CURRENTLY HAVING SOME PROBLEM SQUARING THE GANTRY AND MY STEPS PER INCH ARE NOT 1422.22 ACCORDING TO YOUR CALCULATIONS IN AUTO SET UP THEY COME OUT LIKE 1416.#### THIS A BIG DEAL?

To setup mach3 for the parallel breakout board, view the last three videos on this page:
https://buildyourcnc.com/CNCElectronicsandWiring.aspx#prettyPhoto

The parallel breakout board contains a usb connector, but is only used for power. The USB interface board (sold here: https://buildyourcnc.com/item/electronicsAndMotors-electronic-component-USB-Controller-Breakout) does not use Mach3, rather it uses the planet-cnc software.

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bluechic v4.2 - mach3 setup video does not play on the metacafe site... since I'm new to this I am lost on how to configure mach3 to the usb breakout board. Please advise, thanks!

(These steps are to be taken with precaution, due to the fact that we do not know the model or manufacturers specifications for your BoB)

Here is a link to our CNC electronic videos(

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I have a CNC Machine from China, and the Breakout Board is not Labeled. Is there any way to test the board using Mach3 to find out the pin designations? db25 bob