Hobbiest: Controller Software for Arduino 4 axis CNC with dual Y steppers.

Hello,


This is a very broad question and I hope I am in the right place.


I am making my 2nd CNC from scratch, because I am a glutton for punishment, on a budget to make parts for my projects. I am building this machine to be much stiffer than my last one and also have a rotary 4th axis. The goal is accuracy and ease of use so I can focus on building my skills.


The problem(s):


On a budget and familiar with the electronics in my last CNC I decided I would again use an Arduino UNO with a CNC Shield to run my Nema 17 motors. I have GRBL that is 4 axis (as well as the 5/6 axis version) and the CNC shield worked out where it should be able to perform in 4 axis (CNC Shield instructions say the 4th axis runs on spindle outputs on the Arduino due to memory issues). I am also running CNCJS as contoller software.


The problem is I am getting errors in my controller software when I try to run the 4th axis. There is an A axis I activated in the jog console but no A axis in the programming console. So no travel resolution, max rate, acceleration etc. I have been trying to find where to activate the 4th axis within the program and I am stuck. Can CNCJS support a 4th axis? I also have UGS and I am getting the same issues.


Can the Arduino UNO support 4th axis?


Can my software support 4th axis? Is there something out there that can without switching to parallel port? I have no parallel port on my laptop!


Am I trying too hard to make the Arduino work? Is there another controller/driver setup I should be looking at? I might want to switch to Nema 23's on some axis later. But I am a high school shop teacher so to my budget is limited (otherwise I would have a HAAS). Also I REALLY struggle with computer stuff. Programing and general computer setup causes hair loss! So I need something as simple as possible to achieve because I don't have a lot of hair left.


https://www.youtube.com/watch?v=NUMdmNOUsNs

Video of the CNC coming to life a few weeks ago. The 3d printed parts will mostly be replaced by aluminum later. You can see the temporary setup and wiring for testing. I also have a 1.5kw motor with VFD going in the CNC that I will contol independantly (at this point).

Thanks

I know almost nothing about Arduinos.I looked at them for my hobby machine but went with LinuxCNC as it felt more like the commercial machines I am used to using.I know that it can work with up to 9 axes but wouldn't have a clue about how to make that happen or how to programme it for that level of complication.I assume,perhaps wrongly,that you have a power supply and drive modules in your system and if you do it might be an avenue worth exploring.You might need a Mesa board to run from usb port if you decide to venture into this territory but the stability of the system has impressed me.There is a lot of advice out there on the dedicated forum,unfortunately there seems to be a kind of perverse pride in not making it particularly digestible for those of us who don't eat,breathe and think techno speak.https://forum.linuxcnc.org/

The good news is that the software costs precisely nothing and you can download it to run from a memory stick while you explore the possibilities.Then when you switch the computer off you haven't made any changes to the operating system that normally runs.If you decide to commit it isn't hard to pick up a ten year old desktop box for very little money and it will have more than enough computing power to run most things.It isn't often pointed out that running a CNC machine isn't imposing much more of a demand for computing power than running colour printer.It is frequently not recommended to run a CNC machine from a laptop in any case.

I've been doing a bunch more research and testing and it seems that the Arduino UNO cannot support a 4th axis. I thought that it could do it by using the spindel channel but apparently not. So I have ordered a Arduino Mega (only about $50 for a genuin one). FYI I tried a knock off UNO with my first CNC and had nothing but problems (I think the board was possessed), buy the genuine Arduino!

Also I downloaded the GrblGru Controller software and followed a You Tube video where they used a MEGA, that is how I determined that the UNO cannot do 4th axis. So far this is one of the better GRBL based software I have found, but my favourite is still CNCJS (probably because I am most familiar with it).

Ok, I got my genuine Arduino Mega and I can't get it to work with GrblGru. I loaded the Grbl 5x and it loaded in IDE just fine. I open GrblGru and set it up just like I so with my UNO but with the Mega controller I get the message:

Waiting for Grbl identification....
Grbl not found @ COM4

While this is processing the Rx light on the arduino flashes but not the Tx. I take this to mean that the board is recieving signals but not transmissing back to the computer. Leading me to think I am uploding the program wrong, maybe something to do with "Bootloader" (still don't understand what this is) or there is something wrong with the Mega board.

Any help would be greatly appreciated.

Thanks

P.S. - I also tried it with UGS and it wouldn't connect.

Loks like the module or connection is bad. Do you use the same cable for GrblGru and UGS?
bootloader is (small) program enabling serial communication and some functions like LED control, reaction to PB.
Totally "empty" CPU just reads the memory address 0 and executes instruction found there.