Cncest router dual mode mach3 and grbl

Hi I bought a cncest 3 axis mach3 router but can not get to grips with mach3. I have decided to convert it to grbl and then thought why not have it with both controllers in it. Im thinking if I put another usb socket on the metal controller case I can connect that to an arduino uno grbl board and if I put a 2 position 7 way wafer switch I can switch the inputs to the dm542 drivers to either the mach3 or grbl boards. It has no limits or homeing switches so apart from a probe pin I think that is all I need to do and with no positive to the unused board I dont think it would hurt to link the probe socket to both boards to save amazing 2 probe sockets. There is one extra way on the wafer and that can switch the positive to either board so none of the boards are left switched on when not being used. Has anybody done this modification? Can anybody please give me their thoughts is it a bad thing to do for any reason? I just thought why buy another power supply, 3 x dm542 drivers an enclosure sockets and so on if for £15 i can buy the switch. Any links to this already being done would be good if you know of one but its such a simple modification I dont need to follow anybody else's work but would just be nice to see how they have gone about it.

Presumably no e-stop? No spindle on/off or speed control? In general, it's better to avoid any more connections (=potential points of failure) as you reasonably can, but electrically I guess it will work. Be very careful about ensuring that all the proper ground connections are in place as you appear to be only switching signal connections.

Has anyone done it before? In the sense that there is little new under the sun, probably, but I doubt that many people have as there doesn't seem to be a good reason to do so, generally speaking. I have heard about people switching a single controller between different machines to save having, for example, two PCs in the workshop but that's the other way around.

Again, generally speaking, users decide on their chosen controller hardware and compatible software, get to understand how it works, and stick with it. Switching between different user interfaces is likely to give you more problems than switching the hardware! Yes, Mach3 is a whole lot more powerful than GRBL. In fact, GRBL isn't the issue here as you do not interact directly with it. You actually have to install and run something like Universal Gcode Sender (UGS) to provide the user interface. UGS looks a lot better than when I tried it some years ago for a special-purpose machine (that needed a modified GRBL) but in essence it is a cut-down version of what Mach3 or any other CNC control programme provides. However, as with all software these days, a large part of the task of getting to know something like Mach3 comes down to recognising those bits that are important and those bits which you can safely ignore, at least for the time being. I am somewhat concerned that the problems you have with Mach3 are due to not being familiar with some of the basic CNC machine processes, like how the coordinate systems work, setting work zero, and things like that. Those problems do not go away if you change the control software. I am saying this because I have spoken to and read a number of threads from people in a similar position. I was in exactly the same place myself when I started out, but you quickly get the hang of things with a bit of concentration and maybe a helping hand or bit of advice from time to time.

I would seriously suggest that time spent getting used to Mach3 and its little foibles is more valuable than spending time changing hardware, and will repay you in the long run.

I would also add that I am not knocking GRBL/UGS in any way - there are plenty of people who love it, and the whole concept of "free open-source". But you have already bought Mach3!

Good luck whichever way you go.

[QUOTE=Neale;131959]Presumably no e-stop? No spindle on/off or speed control? In general, it's better to avoid any more connections (=potential points of failure) as you reasonably can, but electrically I guess it will work. Be very careful about ensuring that all the proper ground connections are in place as you appear to be only switching signal connections.

Has anyone done it before? In the sense that there is little new under the sun, probably, but I doubt that many people have as there doesn't seem to be a good reason to do so, generally speaking. I have heard about people switching a single controller between different machines to save having, for example, two PCs in the workshop but that's the other way around.

Again, generally speaking, users decide on their chosen controller hardware and compatible software, get to understand how it works, and stick with it. Switching between different user interfaces is likely to give you more problems than switching the hardware! Yes, Mach3 is a whole lot more powerful than GRBL. In fact, GRBL isn't the issue here as you do not interact directly with it. You actually have to install and run something like Universal Gcode Sender (UGS) to provide the user interface. UGS looks a lot better than when I tried it some years ago for a special-purpose machine (that needed a modified GRBL) but in essence it is a cut-down version of what Mach3 or any other CNC control programme provides. However, as with all software these days, a large part of the task of getting to know something like Mach3 comes down to recognising those bits that are important and those bits which you can safely ignore, at least for the time being. I am somewhat concerned that the problems you have with Mach3 are due to not being familiar with some of the basic CNC machine processes, like how the coordinate systems work, setting work zero, and things like that. Those problems do not go away if you change the control software. I am saying this because I have spoken to and read a number of threads from people in a similar position. I was in exactly the same place myself when I started out, but you quickly get the hang of things with a bit of concentration and maybe a helping hand or bit of advice from time to time.

I would seriously suggest that time spent getting used to Mach3 and its little foibles is more valuable than spending time changing hardware, and will repay you in the long run.

I would also add that I am not knocking GRBL/UGS in any way - there are plenty of people who love it, and the whole concept of "free open-source". But you have already bought Mach3!
Good luck whichever way you


Thank you for the reply.
You say no e-stop and spindle control. The unit has already got an e-stop and I was going to use it to break the supply to the two systems. There is no spindle speed control from the mach3 it is just a pot to set it but I was looking at getting a replacement controller for that and running it from mach3. I understand what your saying about the extra connections to cause a problem but running them through a couple of sealed relays the contacts will have minimal power going through and so the contacts should last forever. Im disabled from a head injury and learning mach3 is too much for me to take in so I will probably just swap out the mach3 board for an arduino with grbl 1.1f and forget about mach3 as I have used grbl a lot in the past.