Gene, Criticism is good. I am most critical of my own work, the only why to not get stuck and improve.
Linus CNC is basically a 1980's software design. It has some rather huge faults. The real problem is that no one was time to do a full-up rewrite. Back in the 1980's computers were expensive and microcontrollers were way-primitive and slow and not really cheap either. Back them a standard PC was the best hardware platform for a CNC controller. Today using a PC running a real-time Linux is about the worst platform. Doing a fresh start in 2020, I'd pick a 32-bit microcontroller platform and then a "hard" real-time OS that is portable over a wide rand of 32-bit microcontrollers. FreeRTOS would be a example of this. See https://en.wikipedia.org/wiki/FreeRTOS These OSes are nothing at all like Linux. They have no user interface and are linked with the application. Al of the real-time functions for the CNC controller would go into the microcontroller. There are about 100 cheap hardware borads thit it could run on. Ths is an example: .../stm32-nucleo-boards/nucleo-f446ze.html <https://www.st.com/content/st_com/en/products/evaluation-tools/product-evaluation-tools/mcu-mpu-eval-tools/stm32-mcu-mpu-eval-tools/stm32-nucleo-boards/nucleo-f446ze.html> These cost about $20 and have a "boat load" of pins all on 0.1" connectors. These must be 100 of these boards on the market. Then the non-real-time part runs on any kind of computer, Mac, Windows, Linux and allows you to run multiple 32-bit real-time controllers if you want to do something crazy like a 12-axis machine. Finally, there is a user interface with graphics. It should run on anything, like a PC or Mac or a tablet and there cold be several of these. Perhaps a touch screen tablet on the milling machine and a second larger screen with a keyboard and mouse. It might be web-based. In summary, We have a single background process that runs as a normal user-level app. I'd write it in maybe Python. It would run in the background on any kind of computer and would the central "hub" of the CNC system. It is what reads the g-code files. Ten there are one or more hardware boards that run a "hard" real-time OS on 32-bit microcontrollers. Each board can run 3 or 4 axis. Most users would need only one board but I don't see why there should be a limit. Thes connect via an IP network, likely for most users Ethernet but could be anything. The central hub process also talks to any number of user interface processes, also over an IP network. The interface from PC app to the controller boards is simple. the boards have a queue of "target states" this a time, location, velocity and acceleration. The board keeps a buffer of these. Because each state is timestamped multiple boards can work together. But how has time to re-do this? LinuxCNC has many problems but it is the best free CNC system out there and it is 100% usable for most purposes. On Mon, Jan 20, 2020 at 3:05 AM Gene Heskett <ghesk...@shentel.net> wrote: > On Monday 20 January 2020 00:42:17 Rafael Skodlar wrote: > > > On 2020-01-19 16:50, R C wrote: > > > well, I just want to test a setup, it by no means is going to be a > > > permanent setup > > > > > > So X-forwarding would work, and is easy > > > > > > > > > Ron > > > > Running X-windows on CNC machines makes as much sense as mounting > > saddle on a caw. > > > > Based on my research LinuxCNC is undesirable in production > > environments or as an option in new CNC products. I spent countless > > hours to find out if any CNC manufacturer is recommending or including > > LinuxCNC with their products. Most small to medium size CNC machines > > in built or kit forms, come with Mach or some other thing. When the > > subject matter comes up I don't recommend their product because it's > > only available on crippled OS. > > > > After decades of proven good records, there is a lot of > > misunderstanding about using Linux in small business environments. I > > hate to write it, but LinuxCNC is not ready for software option with > > new or DIY CNC machines. When I tried to get small business owners or > > others at trade shows interested in LCNC I get questions that are > > impossible to answer. What kind of computer and other electronics HW > > are needed, who's supporting it, how much does it cost, etc. > > > > I can't tell people to come ask questions on this mailing list. > > Discussions more often than not degenerate from the lists main > > purpose. > > > > Suggestions to find a used PC or a motherboard with parallel port are > > just silly. That's fine for hackers with more spare time than $$$ in > > their pockets but not for serious business owners. During my visit to > > EU I could not find a used PC to demonstrate LinuxCNC around. > > > > LinuxCNC is like Apache and such in the 1990s. No serious commercial > > use and support. I haven't seen any job listing LCNC as one of the > > requirements advertised anywhere. > > > > If things were different, open source community would embrace LCNC > > instead of putting their effort into GRBL for example. My choice would > > be a headless Linux based CNC controller with suitable drivers for > > different size machines. GUI would be running on separate system > > connected over ethernet, USB, or even wireless in some cases. Numerous > > robots work that way. > > What utter anti LinuxCNC garbage. Sure. linuxcnc can run when x is > forwarded, but the forward process limits the screen update speed, so > its best running X on its own computer. For instance, using an rpi4b to > run my 11x54 Sheldon lathe with a miss-configured kernel, its stuck in > the on-demand governor, the axis display frame rate is 60 fps. With a > gigabit network, and displaying 2.9-pre linuxcnc on this screen its > about 3 fps. > > I bought myself a 6040 gantry mill a year ago. Came with a cd that > installed mach. 30 ipm max. Came with a 24 volt motor supply so > underrated it actually was in foldback at 14 volts if the rotary axis > was plugged in. Couldn't control the builtin vfd with it, China could > not/would not supply English docs on its vfd. So I grabbed the computer > that had been running a small 4 axis HF mill for about 16 years and > junked the control box the 6040 came with, putting the motor drivers and > a real vfd into the 6040. Now it can move XY at 200 ipm and the spindle > is operated from linuxcnc at any speed in either direction. Because the > spindle is heavy, z-up maxes at about 35 ipm, but it also has a toy > motor (smallest nema 23 I've ever seen, lamination stack under 7/8 inch > long) on that axis that will get replaced eventually. > > As far as your statement about no commercial use? Do some research > instead of spouting off like the expert you aren't, Tormach makes some > nice tabletop cnc machines, for a price of course, but that IS LinuxCNC > behind a gui they wrote called PathPilot. > > Cheers, Gene Heskett > -- > "There are four boxes to be used in defense of liberty: > soap, ballot, jury, and ammo. Please use in that order." > -Ed Howdershelt (Author) > If we desire respect for the law, we must first make the law respectable. > - Louis D. Brandeis > Genes Web page <http://geneslinuxbox.net:6309/gene> > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > -- Chris Albertson Redondo Beach, California _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
