• 1 Post
  • 94 Comments
Joined 1 year ago
cake
Cake day: June 23rd, 2023

help-circle


  • So where do you put the rest of your helices on a cylinder or cone, in 2D? In Flatland a screw or bolt becomes a circle with a short hair. The whole point of “leftie loosy” is to try to help with reality as we perceive it.

    Try it the next time you are underneath a car wielding a socket spanner with a taped on extension thingie that you jury rigged whilst trying to shift a hex nut at 45 degrees to reality that you cannot see, with oil dripping in your eye. Obviously the oil is a mix of the 30 year old native stuff loosened up with the WD40 that might break the rust lock.

    I suggest you do think abut things in 3D and don’t forget the other dimension (time). That WD40 needs time to break the rust lock.

    “Leftie loosy” isn’t for keyboard worriers - its for engineers and technicians, plumbers, and the rest and obviously for DiYers.

    When you are knackered and pissed off and you need to shift a fucking nut or bolt or whatever, you need incantations to get you back on track.


  • Apple: User - you are holding it wrong!

    The spanner is always at 12 o’clock. Either turn yourself or the spanner or your point of view to make it so and then the rule holds. The last option require imagination.

    Take the piss after you have tried to thread a nut on a bolt that you cannot see and tightening it is towards you, at an angle. The nut has to cross a hack sawed thread and will try to cross thread 75% of the time unless the moon is in Venus.




  • They are not a circle unless you have some really odd bolts or screws! I suppose a bolt looks like a circle in “Flatland” but we live in 3D space with time as a fourth dimension that we can directly perceive.

    A screw or bolt and the rest are, roughly speaking, a cylinder with a helical thread on it. They also have a “head” or similar which acts a stopper. You can model all of them as a bolt. We use a spanner, wrench, fingers, screw drivers, drill drivers, scissors, whatever to do the tightening or loosening. You can model all those tools as a spanner (wrench). We need some final mental contortions to make this slightly rigorous: The spanner (wrench) is always considered as being at 12:00 on an imaginary clock and we have to assume that our bolt moves away from us for “tighten” and towards us for “loosen” and I suppose we should also require that we are looking at the “face” of the notional clock and not its obverse!

    Now it should be obvious how the rule works. Turn the spanner to the right and you tighten the bolt, turn it to the left and you loosen it.

    OK that lot is not very helpful when you are under a sink or in a roofing void performing strange contortions. Try holding up one of your hands and pretend you are holding a bolt or the head of a screw. Clockwise turns will tighten and anti clockwise will loosen. You might use “leftie loosey …” to bootstrap: “clockwise tighten”. It becomes even more interesting when you are trying to work out which way to turn a bolt or whatever when you can only feel it and when tightening actually moves it towards you.

    Think about a bolt running through a wheel with the head towards us, say on a very simplified bicycle. Move the bike to the right, and hence the wheels turn clockwise. Friction should cause the bolt to tighten. If you change the design and put the bolt in on the other side and now forwards for the bike is to the left then you will loosen the bolt and that will be dangerous. Now change the design to a bolt with a nut and washers etc and it rapidly gets complicated!

    Also, please note that some bolts have reverse threads to the norm. On a garden strimmer the tightening knob that holds the spool on is often a reverse threaded bolt. That’s for similar reasons to the bicycle wheel thing I mentioned earlier.

    I’ve just spent ages and a lot of words to try and persuade you that this has bugger all to do with autism. I think that your error was really to do with not thinking too deeply about the real issue and focusing on the wrong thing. We all do that, extremely often, regardless of where we are on the spectrum.

    I hope that you see that considerations with regarding helical threads on a cylinder or a tapering cone (but not circles) can be quite complicated and that’s why sometimes we all need some silly rules to get us through the every day ordeal of dealing with them.

    Now, would you like a chat about circles … 8)



  • What are they?

    I ditched Windows roughly 15 years ago and I run a MS Silver partner shop.

    I daily drive Kubuntu (was Arch but I need to tick boxes). I used to teach DTP, WP, spreadsheets etc and Libre Office is fine as a replacement for MSO. Email - Exchange and Evolution EWS. I create the most complicated docs in my firm and MSO works with them OK.

    I 3D print stuff and use LibreCAD and OpenSCAD. All good. Also note that there are lots of other CAD apps on Linux for free/libre and of course we have

    As far as I am aware, games is the only area that Linux might fail and that issue is shrinking rapidly.


  • I doubt it. They make a hell of a noise and print at a rate of characters per second not pages per second. The ribbons suffered from similar issues as cassette tapes (the other ribbons that we had to deal with). The ribbon would dry out if not used for a few days and you’d waste paper and a lot of time.

    DM printers were ideal in the guise of “line printers” - the big old IBM jobbies that munched through A3 landscape fan fold at ridiculous speeds. Home printers like the Epson FX80 or RX80 were at least affordable. I still remember the manual of our RX80 congratulating us on buying it and exhorting me to hug the printer on unpacking it. I suspect the Japanese to English translation might not have been the best.

    We had to get a Centronics interface board stuffed into our C64 and get it working (sacrifice a chicken on a waxing gibbous moon night, etc)

    It worked better on my 80286 box, some years later. I had to set it up in each application - Harvard Graphics, Word Perfect, Super Calc.

    In around 1991 I was able to buy a 80486 based beastie, thanks to gift from granddad. In around 1993 I was given a HP LJ 4P so I could print out proofs for a Plymouth (Devon) tourist tat thing.

    Nowadays I have a fairly elderly HPE MFP five toner humming away at home. Its on a VLAN that doesn’t get to see the internet. It just works. I won’t be “upgrading” it for the foreseeable future.


  • My Epson RX80’s ribbon is somewhere in landfill. The Commodore 64 however is all good and now sports a USB interface with more storage than the poor thing can possibly ever use. The Quickshot II joystick still works too.

    1984ish was when the C64 was bought by my dad, from the NAAFI in Rheindahlen (West Germany, as was).

    Picture the scene:

    Me and brother fly home from UK to probably Dusseldorf at the end of the winter term. Its December in the mid '80s. Every now and then, Russia sends a Tupolev Bear or Badger to chug along overhead. The US sends a YR-71 over the USSR at multiples of the speed of sound. The Cold War was quite unpleasant to live through. Its quite chilly, snow tyres on the car, chains in the boot. The autobahn has the usual psychotic bunch of lane two and three drivers. Lane one generally runs at around 90mph (yes, even back in the '80s)

    We get to home at the time (we move every two years or so - it is the way of things). Dad shows off the new gadget. He plugs the power lead into the video port.

    Some weeks after we have gone back to school for the spring term, the C64 is returned from the menders. We get to use it in the Easter hols. It travelled to the UK and back to DE several times and also to Cyprus (WSBA). The QS II took a serious battering thanks to Daley Thompson’s decathalon.

    I got it re-capped in 2019, which was all that needed doing. They were rather well made …




  • gerdesj@lemmy.mltoLinux@lemmy.mlProblems with Arch upgrade
    link
    fedilink
    English
    arrow-up
    2
    ·
    1 month ago

    What on earth went wrong?

    Arch is just as safe as any other distro, sometimes more so. Being a rolling jobbie, smaller bits tend to break at a time. If you want to live life on the edge then Gentoo is your man but even Gentoo is becoming pretty safe. You might lose your windowing system for a while but you still have links2 to get to a search engine.



  • gerdesj@lemmy.mltoLinux@lemmy.mlRust for Linux revisited (by Drew DeVault)
    link
    fedilink
    English
    arrow-up
    5
    arrow-down
    7
    ·
    2 months ago

    “Every subsystem is a private fiefdom, subject to the whims of each one of Linux’s 1,700+ maintainers, almost all of whom have a dog in this race. It’s herding cats”

    There are three similes in that quote. When your considerations are that disorganized, you have not finished thinking everything through. Fiefdoms, dogs and cats … oh my! That’s on top of wild west and other trite, well worn and rather silly similes.

    Make your argument without recourse to inflammatory terminology and similes and you slighten the risk of pissing people off.

    Clarity is in the eye of the beholder or as someone once said: “You do you”.


  • I like to use my enterprise number and a UUID (all in lower case, for legibility). Here’s an example:

    .1.3.6.1.4.1.33230.0d456e46-67e6-11ef-9c92-7b175b3ab1f1
    
    

    Now you might say that the UUID is already globally unique or at least pretty unlikely to turn up anywhere else, so why bother prefixing it with more stuff? To that I say: “I need to be absolutely or at least reasonably sure … OK nearly sure”.

    Anyway, you maintain a database of these things and then attach documentation and meaning to them. An editor could abstract and hide that away.

    I started this post as a joke. Not sure anymore. Why get your knickers in a twist with naming conventions for variables and constants. Programming is already a whopping layer of abstraction from what the logic gates are up to, another one wont hurt!



  • Windows GPOs are a right old mess. I’ve been managing them for over two decades. The first fuck up is the word “Group”. You cannot assign Group Policy Objects to AD groups unless you use something like ZENworks or some funky WMI filters!

    Settings are applied to computers or users. Many settings are available to be set for both but only make sense or even work for one or the other. MS bought out some solution providers and that’s why you get the Control Panel and other handy stuff, rather roughly bolted on.

    AD with GPOs with the extension to “local machines” is a great idea but dreadful in execution. MS didn’t want to nobble third party apps in the past so that’s why we have this nonsense. Now its all about Azure/whatevs ie MS’s cloud and subscriptions.

    Now you belong us!

    Linux being a Unix has NIS(+) for a directory or LDAP or AD or anything else you fancy. Ansible works for all mainstream OSs, including Windows.

    So often I see people confusing and conflating authentication and authorisation, machine and session state configuration databases.


  • There are so many options it is almost impossible to know where to start!

    Which distro is the VM running (is it even Linux)?

    If you want the VM to use the host’s VPN then you will need some routing and perhaps NAT/masquerade. This is non trivial to sort out. Can the VM have its own VPN connection to your supplier?

    You are starting to reach the point where VLANs/subnets and separate routers (real or VM) may be required. Depending what you use as your ISP router, we might be able to get a solution together - so what model is it and do you have any switches?