[Palladin54]

I'm new to Arduinos. I have programmed computers and PLC's, but not G code. I'm sure I'll be OK programming simple instructions, but I NEED to know HOW to interface the Arduino to control 5 axis for a CNC I will build from scratch. the build is one thing I probably can handle by myself, but controlling the Steppers using the Arduino is where I do not know. I see many boards for 3 axis and even some for 5 axis, but Arduino seems to only handle three outputs for stepper controllers. I saw one system that a guy appeared to put two Arduinos together and I think along with a Raspberry Pi, but I haven't gotten a response from him for over 2 weeks, so I probably won't. Does anyone know HOW I can control 5 or even 6 axis using 1 or 2 Arduinos? It'll be great to know HOW to have a CAD drawing interpreted into G-code too.

[Christian Knüll]

Hi,

don't you think this project is a "little" too big to start with?
At the moment you can't even imagine the problems you will run into - the mechanics and getting an Arduino to generate steps for 5 axis will be some of the smallest problems.

Just one Example:
With a 3 axis machine it does not matter where your workpiece is. The cnc program and machine movements are always the same - as long as your part is within the working area everything will be fine...
With a 5 axis machine everything changes. The final program and machine movements are completely different depending on part location and tool length.
There are a lot of complex calculations involved - and software to do this costs thousands of Dollars for good reasons.

There are a few hobby 5-axis machine projects out there - but I've never seen one actually being "usable" except for some "proof of concept" demo programs.

Christian

[Palladin54]

I will be able to build it myself quite sufficiently of that I'm certain. It's the controlling it efficiently that I need immediate help with. I am building it where I can remove the 2 axis head. I will be able to replace the router 2 axis head with just the router and use it as a 3 axis router. I'm also going to have the main head replaceable with a 3D printer head and hopefully with a laser for etching and drawing. Of course, it can also use pens for drawing too. I'm presently building the 2 axis head. Mainly I need help with programming the Arduino even for 3 axis control, but I want to be able to utilize more outputs for controlling what is on the head. I'll be supplying detailed information for others so they will not have the obstacles I am confronting.
Thanks for the well meant notice of difficulty, but I prefer actual help in doing what I need to get even the simplest up and running.

[Tkamsker]

Look at ramps i have an marlin adjusted to Control a cnc ed proxxon mf70 70 it can do pcb gcode there Are 2 steppers left ..

[wizard]

I think Christian hit it on the head above, this is a huge project to take on for your first machine. I can't say if you are up to it as I don't know your background but keep in mind that this isn't a cake walk.

As for Arduino itself, there are a number of CNC interpreters out there, most being three axis. That probably has more to do with performance than anything else. GRBL is one popular CNC interpreter for the Arduino and from that there has been several forks. Most of these are low performance offerings simply because of the limited performance or the chip in the Arduino. The good thing here is that there are a few attempts going to port GRBL to Cortex M4 chips which deliver much higher performance. So if you want to start with something derived from Arduino these M4 implemenTations would be the minimal required, in my opinion to develop a 5 axis controller.

I'm sure the hobby world would love to see a 5 axis controller that actually works on these low cost boards but there is another option you should consider. That option is LinuxCNC which I believe has a 5 axis solution. Even if they don't, they have a large number of developers acutely familiar with the kinematic involved in developing a CNC controller. LinuxCNC runs on PC hardware and involves the use of a realtime subsystem with Linux. It is a world away from what GRBL does.

[Tkamsker]

I Do retrofit a Bridgeport 412 on linuxcnc *where i needed some pcb s done the cars we use is General mechatronics fpga cars Supports 6 steppers or servos -
My Winter project is an trunnion for 5 axis ,....

[wizard]

If you want 3 axis control GRBL would get you started. However you have close to zero potential of adapting GRBL on an Arduino to 5 axis control and get good results. That is my opinion of course but I just don't see the performance being there.

I will be able to build it myself quite sufficiently of that I'm certain. It's the controlling it efficiently that I need immediate help with. I am building it where I can remove the 2 axis head. I will be able to replace the router 2 axis head with just the router and use it as a 3 axis router. I'm also going to have the main head replaceable with a 3D printer head and hopefully with a laser for etching and drawing. Of course, it can also use pens for drawing too. I'm presently building the 2 axis head.

You are building the head before the rest of the machine? That seems to be a bit backwards. Honestly it sounds like you should be doing two machines here.

Mainly I need help with programming the Arduino even for 3 axis control, but I want to be able to utilize more outputs for controlling what is on the head. I'll be supplying detailed information for others so they will not have the obstacles I am confronting.
Thanks for the well meant notice of difficulty, but I prefer actual help in doing what I need to get even the simplest up and running.

Well as I said GRBL would get you started. It is only 3 axis and the step rate maxes out at 20kHz if I remember correctly. Given that I still think you are wasting your time with Arduinos if you really want to do a controller with the suitable performance.

If you have access to ITunes University there was a good program on there covering robotics and the kinematic solutions involved in getting a robot to actually work. I can't really help as the Math is way beyond my grade level, in any event the complexity grow rapidly as more axis are added. In any event GRBL and LinuxCNC have open code bases that you can study. By the way we aren't trying to discourage you here, I'm certain more than a few people would love to see a robust 5 or 6 axis controller running on one of these new SoC micro controllers.

[Devastator]

I don't know of anyone here who has undertaken such a complex DIY project controlled by Arduino. I can't wait to see what you come up with.

[Christian Knüll]

Hi,

I prefer actual help in doing what I need to get even the simplest up and running.

Then there are 2 options to start with: GRBL or TinyG. Both are open source so you should be able to modify them to your needs.
TinyG is not Arduino but uses an somewhat related but more powerful microcontroller.


Christian

[Palladin54]

I appreciate all the help from everyone. It's alright if I HAVE to use another platform to do what I want. I was hoping I could keep it as cheap as possible for myself and for others wanting to do the same, but it is what it is. I remember seeing one person who had a Raspberry Pi and two Arduinos together and I'd like to know how they were interfaced and how the two Arduinos were able to control 3 axis each and not interfere with the other's code. I don't necessarily need to have all 5 axis moving at the same time. If I can have 3 working at one time, then another combination working at another time to make a piece it should be sufficient for my purposes and most projects being produced. I shouldn't need $5000 CADCAM software to control a truly 5 axis machine with all axis functioning at once.

[Palladin54]

Could you give me better info on where to find what you used so I can research it? Thanks

[Palladin54]

Thanks for the link for your software. I may buy it, but I want to research cheaper alternatives too. I'm embarking on this project not only for myself but for the community as a whole. I plan to document everything I do in detail for others to follow easily. Pointing out the intricate steps and the details that are not so important. I will be posting all the bill of materials, where to buy them cheaply and, of course, the prices I paid.

[Palladin54]

I'm building the 2 axis head first because I want to make certain the the vertical axis will be sufficient for the extra height required for the 2 axis head. I will be able to replace the head with other heads for 3D printing and laser etching and drawing too, but the vertical axis will have to have enough travel for all. Oh, the machine I'm building will NOT be a tabletop model. I'm going to build something that I can rout a small log with (3x4foot at least). I would need 3 axis for the two horizontal movements and one for the vertical, but I'll need another control for the 3D print head, laser or whatever I have for a head.

[ger21]

I remember seeing one person who had a Raspberry Pi and two Arduinos together and I'd like to know how they were interfaced and how the two Arduinos were able to control 3 axis each and not interfere with the other's code.

If only one person has done it, then he's probably the only one that can tell you how to do it.
It's easy to find info on something everyone is doing. It's nearly impossible to find info on something that nobody is doing.

As everyone mentioned, this is a complicated project. You're going to have to learn everything there is to know about controlling a CNC with an Arduino, and then figure out a lot more stuff on your own.

Good luck, and keep us posted on your progress. If you search through the forums here, you'll find countless threads where very ambitious projects just slowly fade away.

[Devastator]

When building something that no one else has likely built, you are pretty much on your own. Hopefully someone will come out of the woodwork who has done a basic version of what you are trying to accomplish. I wish you luck.

[underthetire]

A good start would be the 3d printer side. My printer is basically 4 axis, arduino and g code. Download the marlin firmware and start playing.

[tjbaudio]

LinuxCNC is going to be your best bet for this kind of thing. Opensource, well documented, and VERY extenseble/customizable. I am running it on a FREE computer I got from some one looking to throw it out. A couple of google searches show it is usable on the raspberry pi using some kind of add on card Raspberry Pi • View topic - LinuxCNC An arduio may also work as the add on card. Spend some quality time with google.

[Tkamsker]

Regarding cadcam i think in 5 axis at cheap this is the biggest Issue ,.. But i am thinking what to do as well ,..


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[wizard]

I appreciate all the help from everyone. It's alright if I HAVE to use another platform to do what I want. I was hoping I could keep it as cheap as possible for myself and for others wanting to do the same, but it is what it is.

There are a number of Cortex M4 boards on the market that will give you much better performance relative to an Arduino and they are in the same price range.

I remember seeing one person who had a Raspberry Pi and two Arduinos together and I'd like to know how they were interfaced and how the two Arduinos were able to control 3 axis each and not interfere with the other's code.

It depends upon the implementation.

I don't necessarily need to have all 5 axis moving at the same time. If I can have 3 working at one time, then another combination working at another time to make a piece it should be sufficient for my purposes and most projects being produced. I shouldn't need $5000 CADCAM software to control a truly 5 axis machine with all axis functioning at once.

Once you go beyond 3 maybe 4 axises, CADCAM software gets very expensive. You can actually find lots of free or low cost software for 3-4 axis systems. However the CADCAM software would just be generating G-Code for your machine controller.

As for the machine you are describing I have a hard time seeing any useful 5 axis being done without all axis under control.

[winch1]

I currently have 3 development projects on the go using a pi with an Adruino. It is quite simple to get a 3 axis system working using GRBL to send the G code but it does not have all the whistles and bells you get with Mach 3, just search GRBL or there is a lot of info on the Shapeko site.