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Joined 1 year ago
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Cake day: June 13th, 2023

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  • I’m a mech E in the medical field. We’re consistently understaffed. If I validate an Excel worksheet in Excel '08 or a Python program in 3.5 with a specific version of NumPy, we’re probably sticking with those versions for a while. Every time I bring up re-validating with the latest version, keeping one old system running the old software requires fewer resources than me or a colleague re-validating.

    My whole department is stuck on one version of Python because that was the most recent version when I had an emergency project and developed a data analysis algorithm. We validated it, then as new members were added to my team, they needed a copy, so we had to keep using it. I’ll probably re-validate it to the next Python release. It’s not only unit tests, or we could automate validation. Unit tests are a tiny part of validating software for making medical decisions. And software that directly runs a medical device (like firmware on an insulin pump) is an order of magnitude more rigorous than what I do.

    Side note: there are people who somehow root their insulin pumps and run algorithms on them. There’s a group that can get a PID control loop on an insulin pump that has a more simple control scheme on it (because that’s how the FDA approved it). The company has been trying to get approval to use PID control in the US for years.



  • My third printer, I paid $70 for, used (ender 3 pro return). It was missing several small components, one big part (top aluminum extrusion) that required some machining with a drill press, and had a bad thermistor.

    I don’t think you can get a beginning printer for $100 unfortunately. Sovol and Anycubic make printers among the cheapest that are more beginner friendly (I think) than Ender, for roughly the same price. I have a friend with a Creality and an Anycubic Vyper, and the Vyper seems to be more beginner-friendly. I have two Crealitys and I love them, but both required a ton of modifications to become reliable.

    Can you check your area for a local maker space? My local library has 3D printers for anyone under 18. Universities typically have a few of different technologies (SLS, SLA, FDM)


  • If you have a filament runout sensor, the klipper default settings aren’t great. If the sensor activates, the printer shuts down after about an hour, losing your home position. With a part on the bed, you can’t re-home, so it’s a wasted print.

    The mesh leveling isn’t automatic either. You might want to add either auto-load your default mesh leveling if you always use the same print surface, or put mesh leveling codes in the starting G-code section of your slicer.

    I ran the pressure advance tuning and found that I needed a ton of pressure advance. My prints turned out much better.

    I also got improvements by reducing the allowable deviation in the slicer (G-code files get much bigger, though), and I load files as STEP files directly in Prusaslicer. STL doesn’t have curves, it’s a series of planes. STEP files have geometric primitives and can have curves.


  • Seriously? I was looking at a Surface product recently, and it appeared to have an access panel for the NVME drive. I read a ton of complaints about the dimensions of the drive being unusual, but access to it was easy. I don’t think I was looking at a Surface pro though.

    If a surface pro wants to be a full OS and not a tablet OS, it should be easy to replace the storage device.




  • The one thing I didn’t like about klipper firmware on my CR-10 was the default filament runout setup. One of my first big prints (with expensive ApolloX filament) ran out. The default klipper setup waits something like an hour, with the hot end still hot, then completely shuts down.

    So my home position was lost, and with a partial part on the plate, there was no way of re-homing, so it was a wasted part.

    Make sure your filament runout timeout is set to 24 hours (and I think I might have made the temp lower so it didn’t burn?)

    I like klipper on mine, too. I do wish the default mesh would be loaded at startup, but it doesn’t load any mesh. Which doesn’t really matter, I guess. I have four build plates, three different styles, so I’m running bed levelling pretty much every print anyways.







  • I do a lot of camping in bear country. I’ve been to Bannf. Bear spray is more effective than a firearm at stopping a brown bear attack. Bears have super sensitive noses and eyes, bear spray is immediate pain.

    Bears are extremely muscular from the front, so even if you could manage to shoot one several times from the front, you’d have to use non-expanding bullets like hard cast lead or full metal jacket, which aren’t as lethal as expanding bullets like flat nose or hollow points are (for people). Expanding bullets would be stopped by muscle in bears. Non-expanding bullets are slower at killing things (I believe it’s illegal to hunt with FMJ around me). Bears can run so quickly that a lethal shot killing a bear in two seconds might not be enough time to stop the bear before it could hurt you. And if a lethal shot took a minute to kill a bear, it’s not effective at stopping an attack.

    9mm has stopped brown bear attacks plenty of times, but it’s risky. Both US Parks Service and Parks Canada say bear spray is more effective at stopping a bear than a firearm. I think Parks Canada still uses 0.303 rifles to rangers, but that might be for polar bear. Canada is really strict on pepper spray and mace, but you can purchase bear spray, even if you’re not a citizen. I don’t think a non-citizen would be able to hike with a holstered 10mm or .40SW pistol anyways.

    Bannf was really crowded when I went there. It’s beautiful but the “must see” scenic spots are all filled with Instagrammers. Bears are probably less afraid of people, and I saw plenty of idiots 10 meters from a brown bear with an SLR camera without any precautions at all.

    Pro tip: Jasper is very similar terrain, is also a Canadian Park, and is much less crowded. When I was there a couple of years ago, there was zero cell signal an hour before we arrived at the park. You’ll need paper maps or offline GPS. If you want wilderness with fewer people, try Jasper Park.


  • Second this. If it’s PLA, improving layer cooling might help stiffen the last layer before the next is applied. If it’s not PLA, slowing the print down can reduce the horizontal forces for slower-cooling filaments like PETG/ABS. If there’s any warping or over extrusion leaving little blobs on the surface, your nozzle can bump into them, breaking cantilevered features like this one, or breaking the part off the build plate. Getting retraction to blob less or making sure no over-extrusion exists could help. If it’s PETG or Nylon, printing slightly wet (where the surface doesn’t look bad) can cause blobs on the top layer that the nozzle hits and causes those horizonal forces.

    Drooping like this means something is too soft (speed up cooling on PLA, reduce print speed to give more cooling time and better layer adhesion for any material)

    Prints like this aren’t impossible. I’ve printed a PETG storm drain that had vertical slots like this when I couldn’t buy one I needed. It turned out great but I had to print really slow.


  • Melting tundra releases methane, accelerating the increase in temperature. Rising temperature reduces polar ice, making oceans absorb more heat, accelerating heating. Climate pattern changes cause more frequent and larger wildfires, accelerating heating.

    There are probably processes that work to reduce heating as it increases that I’m not aware of, but there are a lot of positive feedback processes which is concerning.

    I believe the IPCC 1.5C was criticized because it included effects of a carbon sequestering process that hasn’t been invented yet. That’s pretty optimistic.




  • Happened before. I can’t find the story though. I think it was someone who showed up in Europe claiming to be a government official for a South American country. They commissioned printers to make a lot of currency notes. They vanished and it was discovered they weren’t part of this countries’ government.

    Most US counterfeit US Bank Notes are printed in Colombia these days.


  • Thanks for the link.

    It wasn’t an issue with my monoprice, so I might have skipped over some warnings. Then I didn’t read up on all of klipper documentation because I was familiar with it. Maybe I’m warning others about something that’s in the documentation anyways.

    The stupid thing is that I’ve had this happen with my Ender 3 Pro when hooked up to pronterface. I had forgotten it had happened.