My next CNC project - a CNC router

Just an extra data point here.

I've used Mach 3 since 2010 and Mach 4 since 2016. I'm very happy with the system performance and while it is not "real-time" like Linux, in practice with good hardware there is no difference. I run an Ethernet Smoothstepper motion controller with Allen Bradley AC servos and get very high motion control fidelity. From a software perspective it is reliable and easy to configure. There is a good online support community. Mach 4 is lightyears ahead of Mach 3.

My favorite aspect of Mach 4 is the screen and script customizability. I was able to add code to the control which continuously sends commands out the RS232 serial port to query the servo drives for diagnostics, then reads the results and displays them on-screen with graphics. This is not native functionality in the software but rather fully custom code. The screen can be made to look however you want too.
 
macardoso said:
Just an extra data point here.

I've used Mach 3 since 2010 and Mach 4 since 2016. I'm very happy with the system performance and while it is not "real-time" like Linux, in practice with good hardware there is no difference. I run an Ethernet Smoothstepper motion controller with Allen Bradley AC servos and get very high motion control fidelity. From a software perspective it is reliable and easy to configure. There is a good online support community. Mach 4 is lightyears ahead of Mach 3.

My favorite aspect of Mach 4 is the screen and script customizability. I was able to add code to the control which continuously sends commands out the RS232 serial port to query the servo drives for diagnostics, then reads the results and displays them on-screen with graphics. This is not native functionality in the software but rather fully custom code. The screen can be made to look however you want too.
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Thanks for this perspective. All of this is new territory for me so the learning curve is pretty steep so support is a big factor for me. At this point, I need things to be almost "put Tab A into Slot B" on the electronic side of things. I wired my CNC plasma cutter easily enough but this build is definitely more involved.
I'm liking Linux so far and LinuxCNC feels fairly intuitive if that can be said about these sorts of applications.
 
7milesup said:
Just thinking out loud here...
I would love to convert my mill to CNC. Or possibly do what you are doing Dave and build a small-ish platform CNC. Or do both. So little time...
I am curious about the Linux control platform. In one of the other conversion threads on this forum I had mentioned utilizing Linux and was offered a rebuttal as to why it was not the best choice and to use a different control platform. I wish I could remember what the reasoning was.

I have some experience messing around with a large Shop Sabre (Shop Sabre) cutting aluminum. We use a mist system on it which is essential for cutting in aluminum. Without it, the cutter will load up nearly instantly and most likely break, especially if using carbide. Two flute cutter also.

I have considered the Grunblau CNC. I really like his design. https://www.grunblau.com/ Scroll down to the bottom of his page to see his CNC. Also a build thread here https://www.cnczone.com/forums/diy-cnc-router-table-machines/175897-cnc.html

EDIT: Just looked at PrintNC and that looks awesome! Love the linear rails.
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I'd be interested in hearing what the issues were with LinuxCNC. I know that Linux is not everyone's cup of tea as it's pretty geeky to get into. My first experience was converting an old Acer laptop to Linux because Windows 10 was killing it. Linux Ubuntu just flies on it. That's what I'm using as my shop laptop.

That Grunblau machine is really something, excellent design. Thanks for the aluminum tip. I have some moto parts that I want to make at some point, peg mounts and headlight brackets from aluminum.
 
David,

I do control panel design and automation for a job. If you get to feeling overwhelmed, PM me and we can chat and come up with a design for whichever software and motion controller you go with. I've done probably a dozen CNC control build ranging from dirt simple to quite complicated. Some were paid jobs. I've worked with Centroid Acorn, Masso, and Mach 3/4, and once you get past the nuances, they are all somewhat the same.
 
I've done a lot of Linux system engineering on small networking appliances, so I can probably offer some advice on service management and stability, light shell scripting (I've done an uncomfortable amount of shell scripting...), and general Linux tips and tricks. I have basically zero CNC experience, however.
 
Thanks @Badabinski really appreciate your offer of assistance.
 
One final data comment. I have been running Mach 4 on an industrial computer with an absolutely horridly slow Intel Atom processor (about as powerful as a Kindle) and 2 GB of RAM and it has no issues with processing power. This is even below the minimum recommended system values and it still works just fine. I've run it from a laptop (i7 16Gb RAM) and even a desktop with a Pentium processor and 1GB of RAM and they all worked fine.
 
DavidR8 said:
I'd be interested in hearing what the issues were with LinuxCNC
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I suspect that issues with LinuxCNC revolve around the fact that most people are more familiar with Windows (or Mac), and that LinuxCNC has a fairly steep learning curve. If you aren't familiar with the Linux environment and how to do seemingly simple things, it can be a struggle. Having to use a DOS-like terminal for many commands/functions during setups has been a challenge for me.

I'm sure once you get used to it it's fine, but for a novice (me) it's been painful.

Second reason LinuxCNC may not be the best option for a beginner is due to its extremely powerful & flexible nature, there are countless options, features, commands, functions, and other details that may need to be worked out. Getting your head wrapped around the basic architecture and jargon can be daunting.

And there's no customer help number... it's all community-based forum support. Documentation, while helpful as a general guide, is usually outdated.

If you're willing to brave the learning curve, LinuxCNC looks to have pretty amazing capabilities. 9-axis synchronized motion, built-in PLC ladder functions, ability to control just about any type of motor, actuator, whatever. Stuff like adjusting the feedrate based on real-time spindle load and tool center point control like the big boy CNC machines have.

I think LinuxCNC should be fairly easy for a beginner to get working... but that's for simple machines: routers, plasma cutters. For something more complicated (like my 4-axis mill with lots of other nice-to-haves like an ATC, spindle orientation, PDB, 5th axis) LinuxCNC is less intuitive.

macardoso said:
while it is not "real-time" like Linux, in practice with good hardware there is no difference.
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My earlier comment about 'real time' vs Windows wasn't intended to be a dig, or to imply that a real-time OS kernel is superior to Windows-PC based CNC motion control. If you offload the heavy lifting (trajectory planning and precise signal timing) to a dedicated motion controller, then there's no issue. The advantage of a real-time OS is valid when comparing Mach 3 through a PC's parallel port to LinuxCNC through a parallel port.

The only fundamental advantage I can see now is that Windows-based systems can be slightly less responsive to user inputs than a real-time system. By this I mean that pushing a feed-hold button on a Windows system with a separate motion controller (Smoothstepper, UCCNC, any of them) results in some lag or latency (delay). The separate motion controller's buffer has to empty before it can process the new input signal. A large buffer (maybe for a slow PC or big look-ahead) can result in noticable delays. Small buffer, smaller lag.

If you've ever operated a 'real' machine with a dedicated CNC system (Fanuc, Haas, Siemens, etc.) you don't notice any latency when spinning the handwheel or pushing control buttons. Even on old machines.

This isn't limited to Mach 3/4, UCCNC, or other modern(ish) PC-based controls. My 2006 Emco lathe appears to have a Fanuc 21TB control, but it's actually a Windows 7 PC running Emco software that's been designed to mimic the Fanuc user interface. This also has a bit of latency in the controls... switch to a real Fanuc controller and everything is instant.

Not a deal breaker, but a half-second feed-hold delay during a rapid down in Z can cause some puckering.

-R
 
Dave... I looked for a while to find the post where one of our members suggested a different OS than Linux. Could not find it. I know nothing about Linux but it seems that the people that use it are happy. I am considering that route myself.
You may have already seen this, but there is a guy that did a CNC conversion of a PM833 mill, which I know doesn't apply here but he did use Linux and talked about how to set it up. PM 833T CNC conversion utilizing Linux
 
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