Threads for samuelt

    1. 1

      Rottenest Island, and then flying back to the USA.

      1. 1

        Is that the island where the Quokkas live?

    2. 1

      LinuxCNC controls CNC machines. It can drive milling machines, lathes, 3d printers, laser cutters, plasma cutters, robot arms, hexapods, and more.

      Runs under Linux (optionally with realtime extensions).

      I see the dependency on Linux (even the name!) as unfortunate.

      1. 4

        What are your main concerns? What would you do differently?

        1. 1

          I’d care about supporting non-Linux OSs, particularly the OSS ones, and avoid including Linux in the project name.

          1. 5

            Patch or gtfo then :)

          2. 2

            Cross-OS for its own sake is fair enough I suppose, though I’d still be interested to know what about Linux you think is unfortunate as the OS of choice for this project, or why you think another would be better.

            My take on this is: it’s a piece of software designed for industrial control with hard real-time requirements. As one of my mentors liked to say, a mill or a lathe isn’t the kind of equipment that just hurts you, it rips your arm off and beats you to death with it. I’m glad that they’re limiting their scope to a single kernel. Last I read an article about achieving hard real-time on Linux, it wasn’t exactly lacking nuance or pitfalls. Add more supported kernels and you multiply the chances that you introduce a bug, miss timing, and destroy the work/machine/operator.

            I’d also like to point out that they don’t owe anyone cross-OS support. Including Linux in the name actually emphasizes their right to build what they want. The creators set out to create a CNC machine controller for Linux. If you want support for another OS, the source is GPLv2 :)

            1. 1

              what about Linux you think is unfortunate as the OS of choice for this project,

              I’ll say as a start I don’t think there’s anything terribly wrong with doing CNC with Linux.

              Yet my suspicion is that, despite the name, there’s technically not much tying this project to Linux specifically.

              Which makes the name truly unfortunate.

              1. 6

                A brief look at the project reveals that they ship Linux kernel modules for controlling hardware via supported interfaces, and for any use with real hardware Linux kernel with -rt patchset is needed on the controlling computer. This surely makes moving to another kernel quite a large effort, as realtime drivers need to be ported. And the recommended installation method is a Debian-derivative GNU/Linux distribution.

                So I would expect getting a good enough port to be a large undertaking, with benefits of using another OS inside that black box even harder to realise because the number of users with hardware access matters for testing.

                1. 1

                  So it is forcibly an ugly design, as we know it has to resort to kernel modules as Linux itself is ill-suited to abstract the hardware and enable doing the heavy lifting in user space. Noted.

                  Maybe the name is not wrong, in hindsight.

                  1. 5

                    Sure, they do have a userspace implementation, and apparently recommend the standard Preempt-RT patchset with user-space control implementation for some cases. It’s just that for many cases RTAI kernel and a kernel-space driver yield lower latency. Indeed, Linux is not a microkernel, so context switches have some costs.

                    Sure, making something realtime on top of a general-purpose non-realtime OS has its drawbacks, and the best latency will need some amount of special-case work. But it improves the chances of reusing some computer that is already around.

                    User-space real-time API-wise they claim to support Preempt-RT, RTAI and Xenomai kernels (all Linux-based).

                  2. 3

                    Such machines rely on hard realtime controls and are very often done in microcontrollers. Latency is a huge constraint of the project. The project itself is very old: it dates back to the mid 90s: there wasn’t a lot of CPU power back then (especially on the ARM targets) and less knowledge and development to achieve hard real-time.

                    1. 1

                      Are you aware of an open effort using microcontrollers?

                      1. 2

                        GRBL, I guess? Somewhat limited and recently inactive, but apparently usable for many usecases.

                        1. 3

                          recently inactive

                          There seems to be a maintained fork. There’s not much in terms of changes, but I suspect that’s because it reached a “just works” point.

                          No strange latency surprises to be had with these microcontrollers.

                          1. 2

                            Yes, I meant this repository as the main development line, and it doesn’t seem to have firmly decided to never get to 5-axis support, so there is a clearly stated missing feature with respect to which it could be active but isn’t. Doesn’t matter for use cases where it fits, of course.

                      2. 1

                        The project wiki (section 4) describes why they chose not to use an external microcontroller as a motion controller.

                        It also says there was a hard fork which adds support for a particular external microcontroller.

                        1. 1

                          I see… ultimately they do like their scope and meters, on their computer.

              2. 1

                Yet my suspicion is that, despite the name, there’s technically not much tying this project to Linux specifically.

                I’m unfamiliar with the real-time / CNC space. What other non-GPL/OSS kernel systems have support for the kind of real-time performance required by these machines?

                1. 1

                  What other non-GPL/OSS kernel systems have support for the kind of real-time performance required by these machines?

                  As a reminder, Linux isn’t exactly awesome at real time, particularly awful without rt patchset (and project seems to work w/o that), thus the requirements can’t be that strict, and there should be plenty of systems that meet them.

                  1. 3

                    In the system requirements documentation:

                    It can, however run on a standard kernel in simulation mode for purposes such as checking G-code, testing config files and learning the system.

                    So, non-RT Linux allows to do a subset of work that doesn’t involve driving hardware.

      2. 3

        Are you coming at it from a principle perspective or practical?

        From a practical point, several of the newer commercial control systems like Heidenhain and Siemens and probably more I can’t remember, have Linux base for the user interface.

        Both works fine in daily use at the day job.

        And is Windows really a better option? I know Datron’s Next control is lovely and easy to use on the commercial side. Others include Centroid, UCCNC, Kflop, Planet CNC and Mach3 & 4.

        All require specific electronics anyway that usually does the heavy lifting in serious (non hobby) use.

        From a principle point, I’d like to hear more.

    3. 2

      Lots of nice new stuff!

    4. 5

      Nothing IT related at all.

      Taking apart and cleaning up a horizontal milling-machine, it is quite filthy. So I expect to spend lots of time with soapy water, de-greaser and various cleaning implements.

      After that, reassembly and checking squareness and alignment. I expect both to be quite horrible.

      And perhaps using my lathe to create a holder for my lathes top-slide, to enable the use of the top-slide to bore or grind out the dramatic gouges in the spindle taper.

      To be slightly more clear, I need to run the machine spindle without a tool mounted in the expected place and mount a different kind of tool and traverse it diagonally and not in-line with the normal machine travels. Also I’ll be cutting in to the machine using itself using a boring-bar or a grinder.

      An approximation on a very different kind of mill.

      But realistically cleanup and reassembly done would be enough to make me feel like I accomplished something worthwhile, because the assembled parts to be mounted weigh a few hundred kilos and requires the use of a hydraulic engine/shop crane to lift.

      The mill is without any manufacturers markings and looks like this.

    5. 1

      I pay for

    6. 1

      I don’t do backups currently.

    7. 1

      I forgot about this post… It also took me over the 50 point limit, so thanks everyone!

    8. 6

      xmonad as a windowmanager in XFCE, when I get to run something other than MS Windows. Which I need to do much to often.

      A cleaner examle than my own config.

    9. 6

      Fantastically horrible! I love it.

      Excel + VBA can do really horrible things if one puts ones mind to it.

    10. 3

      I am still confused how it is even accepted in the USA that a banking website allows you to do whatever to your account by means of some password people are likely to use in many places. Here in Belgium we also have online banking, but you are provided a card reader by your bank to use it.

      In order to do anything online to your account, you need to have your card, the card reader and your card’s pin code. Logging in requires you to receive a challenge number from the bank’s website, you slide your card in the reader, enter the challenge number and your pin code in the reader and receive another number that you enter in the bank’s website. You repeat this process when making a payment or something similar.

      I know, it’s more cumbersome. I do feel rather secure with it though.

      1. 1

        Some swedish banks use as similar system.

    11. 2

      Thanks @conroy for the invite!

      The user-tree is interesting, I think.

    12. 1

      Sounds like a nightmare.

      Imagine that in the near future you were burgled without obvious signs of breaking and entering…

      Tenant: But I locked my door when I left on friday! I’m sure I did!

      Insurance bureaucrat: But your lock, windows and door are all whole and the lock-log doesn’t have a break-in alert logged, it just show that you sir, entered your apartment at just before midnight on saturday.

      Tenant: But I was on a freakin' airplane at the time!

      Insurance bureaucrat: Our records clearly show that you entered your home and therefore can’t pay you for this supposed burglary and items you claim are missing.

      Tenant: GAH!

      Insurance bureaucrat: If you persist in claiming this was a burglary, we will have to sue you fraud. And according to our terms of service you agreed not to mention any insurance claims in public, regardless of their outcome. If you do, it’s slander and we’ll sue.

      Have a good day sir and good bye.

    13. 2

      Beautiful! clever!

      But I don’t think it is what most of the current mac pro owners want. But perhaps Apple doesn’t see them as the primary target market?

      1. 1

        What do mac pro owners want?

        My guess would be a zillion CPU and GPU cores and easily expandable fast storage. Seems to fit the bill. Six thunderbolt ports makes it even easier to add storage than internal hard drive trays.

        1. 1

          Sure, there is plenty of expansion via thunderbolt, but what about any internal expansion cards such as specific cards for video editing?

          And while it has two GPUs, it, as far as I can see on Apples images, has only one CPU. And the written information also only mentions processor in singular form.

          Sure you can get a pci-express to thunderbolt adapter in an external box. But that’s ugly and yet more money on top of a new machine. Or they can wait for their vendors to release specific thunderbolt interfaces for their needs. Which will cost both money and time.

          But since I am not the target market for the new Mac Pro, I obviously can be wrong.

          And perhaps those that really need more gpu power and faster cpus will buy them. But I think some will have to consider switching to PCs for their specific needs and will be vocal about their disappointment in Apples new Mac Pro.

    14. 1

      There is also unclutter, which has been around for a while (since 1992 or so…) and does the same thing. This project have shorter and generally nicer code in my opinion, but unclutter has a man-page, probably has had most of it’s possible bugs removed and is already available in many package repositories.
      Debian and Ubuntu makes it just an apt-get install unclutter away.

      1. 1

        but unclutter has a man-page, probably has had most of it’s possible bugs removed

        If you read the readme, you’ll note that I wrote xbanish because unclutter doesn’t even work properly anymore.

        1. 1

          Ah, sorry, I completely missed that. Oops…

          Anyway I use unclutter like this: unclutter -idle 1 -root

          This only shows my cursor when I move it, which is what I thought xbanish did and is what I want to happen.