BYCNC Response:
This is correct. You will need to use a method appropriate for the software you are using. Also remember that NC switches are typically wired in series, while NO switches are normally wired in parallel.

User Response:
I am using the cnc planet software for your USB board. Are the limit configurations in this software?

BYCNC Response:
Yes, Planet CNC software is compatible with the use of limit switches. Configuration information will depend on your specific application. You can view Planet CNC's information here: http://www.planet-cnc.com/files/CNCUSBController.pdf

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Limit switches for axis. The print shows that you can wire the limits either n.o. or n.c. so if this is correct I would need to tell the board in the software how to look at these limits, I'm either going to get an input or loose an input depend on how i wire it.

It's generally acceptable to use one pin for all of your limit switches wired Normally Closed (NC), and another separate pin for a Z probe that is Normally Open (NO). LinuxCNC is quite flexible and allows for mixed configurations of NC and NO switches.

Just ensure you configure LinuxCNC correctly to recognize each pin's logic (Active low or active high). And perhaps run a few tests before running the machine.

Additional Information:
It's generally acceptable to use one pin for all of your limit switches wired Normally Closed (NC), and another separate pin for a Z probe that is Normally Open (NO). LinuxCNC is quite flexible and allows for mixed configurations of NC and NO switches.

Just ensure you configure LinuxCNC correctly to recognize each pin's logic (Active low or active high). And perhaps run a few tests before running the machine.

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[59] is it ok to use one pin for all of the limit switches wired NC and another pin for a z probe that is NO, or do all input pins need to be the same (NC or NO)? I would like to use LinuxCNC but will use Mach3 if necessary. a thanks!

A wireless MPG is generally independent of the controller since it communicates to Mach3 directly and does not pass through the controller. I am using a wireless MPG and I have no problems with either of the controllers that I sell (Mach3 USB controller or the Pokeys57CNC controller).

The issue you are having may be in the configuration of the wireless MPG that you are using.

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I am trying to decide which board I should use. I have a wireless MPG and every time I jog Z my X axis steps. If this is not a board issue I would like to go with a wired MPG. So I would like a board that I can have a wired MPG, use a tool touch off probe, control either spindle (VFD) on/off or on/off with speed control, and have homing switches.

I would not recommend slaving an axis using the method of taking an additional axis from the USB interface. Instead, wire both drivers to a single axis on the USB interface. This will insure perfect signal output to both drivers. If you requre the motors to spin in opposite directions, simply wire one of the motors to the driver reversing the coil A and B connections, or use a hex inverter (https://www.buildyourcnc.com/tutorials/Tutorial-Two-Motors-Spinning-Oppositely-On-Single-Axis).

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I purchased a USB Breakout board, motors and drivers, paid for CNC USB Controller Software and I CAN NOT "Slave" an axis, but there is an option to do that. The moment I connect USB Breakout Board "Slave" option becomes shaded and I can no longer select it (becomes not functional). What is going on? Need help asap. Thanks

if you purchased the USB interface, you will need planet-cnc software rather than Mach3, and you will need a usb cable to connect the usb interface to the computer.

The blackToe 2x4 CNC Machine Kit with optional table will need wire to connect the electronics. Don't forget to get some end mills to use for cutting the intended material.


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Additional Information:



Additional Information:

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If I purchase the [blackToe 2x4 v4.1 CNC Machine Kit - USB Electronics - Table Included] all I would need for this CNC to be fully operational is a laptop with mach 3 software and a router. Is this correct?

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?

When wiring the limit switches to our BoB(breakout board), depending in the older model or our revised version (https://www.buildyourcnc.com/item/electronicsAndMotors-parallel-breakout-relay#prettyPhoto/0/), the older version will need the COM (limit switch) connected to 5V and the NO/NC to your input pin, but with our newer version you will use GND(ground instead of 5V) to common and the same for NO/NC but the setup in the mach3/confi/ports&pins/ is still the same.

Here is a tutorial where you can see how to set up the limit switches correctly (with our older parallel BoB): Part 1:(

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I am attempting to set up limit switches on the 5 axis parallel breakout board that came with my BlackFoot kit. The output pins are driving the motors perfectly, but I can't figure out the input pins. With one lead in the 5V pin and one lead testing the input pins, my multimeter reads 0V for all of the input pins. Shouldn't those circuits be +5V? Where am I going wrong?

You can download a trial version of PlanetCNC software from their site at http://www.planet-cnc.com/index.php?page=software to see how you like the interface. If you look at their main GUI screen, along the left side you will see 4 boxes labeled X,Y,Z and A. These represent the axes the software is equipped to control. (A being Axial, or rotational motion) Typically a separate motor and driver is used to control each axis. If you plan to switch axes you will need to connect and disconnect the outputs from your software to the drivers.

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sorry, this is what i meant to say: OK, so if I use the USB version then I would find the rotary/linear axis definitions in the planet cnc control software somewhere. I will be needing to change axis type often for various projects that is why I am asking.

NC mechanical switch configuration is supported. You can download the manual from this page (Mach4 plugin and manuals):
https://buildyourcnc.com/item/electronicsAndMotors-electronic-component-breakout-Mach4-mach3-USB-ethernet-Board

The pokeys57CNC controller has input terminals and pins for limit switches on each of the 8 axes. There are three separate inputs per axis, two for the actual limits of that axis, and one for the home position.

Connect each switch between the GND terminal and its respective axis limit terminal/pin. For instance, the limit switch will typically have three leads, COM, NC, and NO. In an NC configuration, the NC connects to the terminal/pin, say, Axis 1 lim +, and the COM connects to the GND terminal.

In Mach4, in the new device wizard, make sure to specify the correct option on the home and limit switches that matches the machine configuration.



Additional Information:
can you use one switch per axis for home only?

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Hello, I am trying to configure Home and Limit switches using the Pokeyes57cnc and NC switches. I am confused on the procedure of setting this up. wiring to the board and setting up in Mach4. Can you direct me to a tutorial or offer some suggestions? Thanks Dale

You can find the datasheets to our motors be going to the the stepping motor category page https://www.buildyourcnc.com/category/nema and selecting the motor. This will bring you to the product page for the motor and all of the motor information will be found there.

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I would like to design my own CNC router around one of your electronics bundles, either the 3 Axis - Heavy Gantry or 3 Axis - All Large Motors. Do you have the data sheets for the motors so that I can use the dimensions in my model?

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.

Recommended action
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.

Additional Information:
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.

Always defer to the advice of a professional electrician. If your professional electrician believes the wiring of the VFD is incorrect as per our recommendations, always use the advice of the professional electrician.

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When wiring line voltage to the VFD your diagram shows one line of 240 going to the R terminal and a neutral going to the T terminal. My electrician thinks this may be incorrect and he believes that one leg of 120 should run to the R terminal and the other leg of 120 to either S or T. Is this correct and if so should the second leg/pole be run to S or T? Thank you

The hookup wires you will need is 22 to 24 AWG stranded and shielded for the wiring of the limit switches and E_Stop. Our kit customers select various places for these switches, so we don't supply the wiring. If you don't use shielded cable, you will need to change the debounce setting in Mach3 (if that is the control program you are using).

We typically use 14 AWG stranded wire for the VFD to Spindle (U, V, W) connections.

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I recently received missing stop button and limit switches in my 5x kit. Thank you. Is there suppose to be any bulk wiring in kit for limit switches and 2.2 spindle? If not could you please describe correct gauge wire for both? Cheers.

You can put all of your limit switches (including the E-stop which serves the same purpose as the limit switches) and home switches on a single pin. When homing, mach3 will move the axis it wants to home, hit the switch, pull away from the switch, then move the next axis and repeat the steps for the next two axes.

The probe is on the 2nd pin. The SuperPID is on the 3rd pin and now you have another pin remaining.

The GND terminal can be doubled up.

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Additional to Question 3444: Additional Information: To Clarify: I need to set up 3 home switches which can double for limits (that's 3 pins.). Another pin for a probe. That's 4 pins used. Now I need to set up the other limit and E-stop switches. No pins left, how do I do that? Can a ground pin be doubled up on? Plus, I have a SuperPID. Another pin?

The connections between the driver and the breakout board(USB/Parallel)22-24 AWG wire is preference also going from the potentiometer going to LSPS(laser power supply) , now going from the power supply to the drivers/laser power supply 16-18 AWG wire is our preference.

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I'm about to order your laser cutter , item 279 and a little confused.. in your faq it states you need wire and connectors for assembly, can you be specific on amount and guage of wire or tell me where to find that information?

You will want to connect the homing switches (which may also serve as your near limit switches) to different input terminals. It's ok to add more limit switches with the home switches, but each home should be on independent inputs. For example, connect home X and any other limit switch to IN1, connect home Y and any other limit switch to IN2, and so on. This will allow you to properly use the "ref all home" button in Mach3.

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In the instructions (diagram 1) you show all the home switches connected in parallel? But here you say they need to each have their own inputs. "You will want to connect the homing switches (which may also serve as your near limit switches) to different input terminals." I dont see how the second and third axis can go home if the first axis has already closed the parallel circuit unless they back off a bit until the switch opens up again before the next axis goes to home? My machine has no limit switches so I assume they are home switches.

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[575] I have finally got my limit switches wired and working - thank you. Can they also used as homing switches and if so it it just a question of looping the two inputs on the board i.e. the limit and home terminals IN2 to IN3

This video should provide enough guidance to understand the PWM signal on the Mach3 USB controller:

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[575] Hello, I'm wondering if you can provide advice how to wire this USB board where for spindle I would like to use chinese servo motor and driver (TD3) - speed control mode. Especially how to connect - AVI, ACM and 10V (24V is clear). I am still not sure how to power on and off spindle itself. Thank you in advance. Vaclav

This would totally work for that application. This cable carrier is used for any object that needs to move and carries some electrical or tubing within it. This cable carrier is great for cable management where you want to make sure the wires and tubes are in a position that you set, not where the wires and tubing want to go.

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[311] I am looking to use this type of thing with a pipe for theater. Where the pipe can be lowered and it would have electrical and signal cable inside. Is this good for that or should I look at something else?

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!