Michael K Johnson

https://social.makerforums.info/@mcdanlj

1st Fedora Project Lead. Co-author Linux Application Development. Pendo Distinguished Engineer. Ex-{Linux Journal, Red Hat, rPath, SAS}. Christian. Father. Maker (including machining, 3D printing, and electronics). Books. Classical music. Aviation (PP-Inst-SEL). Amateur Radio KZ4LY

#searchable searchable (please index my posts for search purposes)

Occasional Blog: https://musings.danlj.org/

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npub1uwxhavnjxem0gvgghxk6x8xtdhue0yrnenv8evsk55d29ayuhhvsmnqf0h

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mcdanlj_at_social.makerforums.info@momostr.pink

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nprofile1qqsw8rt7kfervah5xyytntdrrn9km7vhjpeuekrukgt22x4z7jwtmkgprpmhxue69uhhyetvv9ujumt0d4hhxarj9ecxjmntqyt8wumn8ghj7ct5d3shxtnwdaehgu3wd3skueqxh8p76

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atlas.nostr.land

nostr.mom

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Last Notes

2026-03-16 02:28:32 UTC

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The profuse variety of these with various features and voltages from Pololu is amazing. I sometimes wish I owned ten of each... 😀 Many fixed voltages. Some adjustable. Some buck-boost. They've done a particularly nice job making small units that mostly fit in the space of a T220 linear regulator.

2026-03-03 21:15:58 UTC

**This is amazing.** EA1FUO has built nec2c into WebAssembly, and now [you can do antenna simulations on your phone or desktop without depending on nec2c running on a server](https://ea1fuo.github.io/AntennaSim/ ). You can also deploy it locally, and he provides instructions for how to do this on docker or bare, and you can run nec2c on the server if you like.
Takes seconds to simulate my inverted V, and it even displays updates on what it is doing while running the simulation. It then gives a 3d rendering that you can drag around to get a better intuition. As you hover your mouse over the model, it shows gain in dBi with elevation and azimuth.
Beautiful work!
I don't know where else he's active, but he's been posting about this on Reddit as he's been developing it:
https://www.reddit.com/r/amateurradio/comments/1rfsr6f/my_new_modern_free_and_open_source_antenna/
Source code GPLv3: https://github.com/EA1FUO/AntennaSim
#HamRadio

2026-02-28 23:18:52 UTC

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My wife and I did our first shingles shots as a date. 😀

2026-02-12 13:34:38 UTC

RE: https://swecyb.com/@anderseknert/116056950299738296
If you pull the trigger on a gun, you are responsible for whatever the bullet does, *regardless of whether you intended the particular outcome.* The legal consequences of a bad outcome might be different based on your intent (e.g. manslaughter is a lesser charge than first degree murder) but the fact of your responsibility doesn't change.
If you loose an AI agent on the world, giving it "agency" to interact "autonomously" with others, *you personally are responsible* for what it does, whether you intend that outcome or not.
Whoever is responsible for "crabby-rathbun" on github is absolutely as individually personally responsible for the attack that their "AI agent" perpetrated as if they had personally written the offensive blog post. Someone made the decision to give this code "agency" to operate "autonomously" and we really need to know who to hold to account for this antisocial behavior.
#note1jau…a84k

2026-02-04 15:25:19 UTC

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"We redefine 'at rest'"

2025-12-21 12:49:15 UTC

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That seems to me like a really important affordance for ATC immediately and intuitively knowing that they are dealing with a robot. Not that I'm an expert but even just as another pilot following traffic around me, hearing it sound robotic would be valuable information.

2025-12-21 12:05:36 UTC

Airplane with incapacitated pilot lands safely thanks to emergency autoland system:
https://avbrief.com/autoland-saves-king-air-everyone-reported-safe/?utm_source=newsletter-88&utm_medium=mastodon
I haven't listened to the attached LiveATC recording, but there is one if you are curious how an air traffic controller would mix emergency automated traffic with normal human-piloted traffic.

2025-11-07 02:21:24 UTC

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Did you use NAS drives in it? They add some jitter to head movement so that RAID doesn't cause death by resonance.

2025-11-01 12:13:24 UTC

I know that sentencing kids to tooth decay is small potatoes compared to lots of the rest of what this administration is doing, but this still makes me angry.
(Yes, I know, if we removed all processed sugars from our diet, that would also address tooth decay in a substantial way, but also let's be honest about whether that's going to happen.)
https://www.wral.com/story/fda-restricts-use-of-kids-fluoride-supplements-citing-emerging-health-risks/22224783/

2025-09-06 18:46:47 UTC

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Good to see the AP calling out Kennedy's lies.
https://apnews.com/article/fact-check-kennedy-rfk-congress-senate-vaccines-covid-deaths-hospitals-efa457f139dabcce6f54c0ac2c590512

2025-09-04 22:51:32 UTC

> **"**> Saying I'm anti-vaccine is like saying I'm anti-medicine," Kennedy said
Yes, Mr. Kennedy. Yes, it would be. And it would be **true.** "Anti-medicine" is a great and fitting way to describe you.
https://www.npr.org/sections/shots-health-news/2025/09/04/nx-s1-5528966/rfk-kennedy-hearing-covid-vaccines-cdc

2025-07-22 18:14:28 UTC

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Oh, I didn't realize that Sovol went with a proprietary nozzle for with the v8, when part of the attraction was "pre-assembled Voron" basically...
Interesting idea here to use washers to use standard volcano nozzles:
https://www.reddit.com/r/Sovol/comments/1f1tz9n/sv08_hardened_nozzle_vs_generic_k1_nozzle/

2025-07-22 14:17:31 UTC

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Can you get carbide nozzles? Far harder than hardened steel, more heat-conductive than brass, no need to increase temperature...

2025-06-28 23:12:04 UTC

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Most of the people higher in the bands are also going too fast for me! 🤣

2025-06-07 21:07:03 UTC

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Didn't AlmaLinux preserve support for the older systems?
Yeah, looks like it did:
https://almalinux.org/blog/2025-05-27-welcoming-almalinux-10/

2025-05-26 21:57:18 UTC

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So glad that turned out better than it could have!
A log in your eye can turn out so much worse... 😬

2025-05-01 03:08:07 UTC

Ah, I was wondering what kind of aggressively user-hostile things Bambu had done lately.
Don't. Buy. Bambu.
Seriously.
https://github.com/bambulab/BambuStudio/issues/6726

2025-03-27 22:07:39 UTC

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About 20 years old. And printer room has multiple windows, not air tight. Understand, apples and oranges.

2025-03-27 21:43:24 UTC

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YMMV but I went from "never print that stuff again" to "whatever, it's fine" from the family by adding active carbon filtration (and HEPA).
And it looks like the Sovol Zero does have that.

2025-03-27 20:49:46 UTC

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OK, planning active heating, so a fast printer appropriate to be someones first printer that works well with ABS?
> combined with the upcoming chamber heating component
Looks nice!

2025-03-15 13:56:06 UTC

I was looking for something else in my old photos and came across these pictures of violets taken in the NC wilderness, in Pisgah National Forest, a few years ago.
I still haven't gotten over the fact that we can carry in our pockets cameras capable of pictures like this.
#BloomScrolling
https://social.makerforums.info/system/media_attachments/files/114/166/769/665/584/049/original/1bd68007dd60fb04.png
https://social.makerforums.info/system/media_attachments/files/114/166/770/742/481/341/original/90a85f624b9b8c51.png
https://social.makerforums.info/system/media_attachments/files/114/166/771/499/591/459/original/576c6313b87bb0d4.png
https://social.makerforums.info/system/media_attachments/files/114/166/772/593/705/121/original/ab301439ca858a93.png

2025-02-08 20:49:40 UTC

As a new ham, I am trying to learn morse code for the fun challenge.
Last night, I was practicing "head copy" of morse code by listening to conversations, and found a CW QSO (morse code conversation) slow enough that I could follow most of what I could hear. There was a lot of QSB (signals were fading in and out), which could have made it a lot more stressful, but actually made it *less* stressful, because I had an excuse not to be catching everything. "Oh, I couldn't understand that because the signal wasn't very good." 🙄
Somewhere in there, the signal faded in and I heard a clear "73" (code for "best regards") but then it was immediately followed by "00" and I was confused as it faded back out. What was that about?
As I was falling asleep, I was mentally practicing sending morse code, and imagined sending "RIG IC 7300" (my radio is an ICOM IC-7300, a very popular entry-level radio) — and realized what the 7300 I heard probably had been. 😀
#HamRadio #AmateurRadio

2025-01-31 13:27:43 UTC

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That brings back childhood memories of the parakeet who would fly over to the piano every time I started practicing and sing along for the entire practice session. ❤️ (We put down regularly-refreshed paper on the shelf above the piano for obvious reasons...)

2025-01-19 17:48:10 UTC

In March 2023, I ordered nickel strips and acetic acid to make nickel acetate and start #diy nickel plating in my shop.
Then I didn't actually do it.
Today I finally put those nickel strips into some of the acetic acid and turned on the power supply. Starting to get a little bit green at the bottom!
Also, I have been planning for years to set up for aluminum anodizing. Finally bought all the remaining items I need yesterday, and planning to start actual anodizing process later today.
Finally got to these projects because of an extended family member is visiting. He is learning to use the lathe and mill, and wants to anodize and nickel plate parts he is making. Apparently I'm motivated more by doing things for others than myself? #making

2025-01-18 16:42:13 UTC

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This is the kind of almost-but-not-quite there that made me say that my Qidi X-Max3 isn't a great *first* printer, unless you love tinkering (like I do).
Qidi aren't perfect, but they haven't done the kinds of user-hostile changes that Bambu have.

2025-01-18 14:01:49 UTC

I used to reluctantly tell newcomers to #3DPrinting considering a Bambu printer that Bambu have at least done a pretty good job of "it just works out of the box" based on lots of reports from normal people I know personally (not just "influencers" to whom Bambu gifted a printer), while mentioning that they started by claiming that they didn't have to follow open source license terms unless they wanted to. But with this move, I will instead have to tell them that "buying" from Bambu is really renting printing functionality from a company that may arbitrarily take away some of that functionality after an indefinite and unstated term.
I need to think more about what to recommend to newcomers who Just Want To Print, because I am asked often enough that I should have a better answer.
https://forum.makerforums.info/t/bambu-tightens-the-noose/92408?u=mcdanlj

2024-11-30 16:12:43 UTC

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What orientation will you print that in?

2024-11-23 01:23:30 UTC

I've had my #HamRadio license, with my call sign KZ4LY, for a month and a half, and no one has corrected my saying "kay zee fower ell why" instead of "kay zed fower ell why." I'm used to "zed" from folks outside the US, but it took me this long to realize that **US** hams also use "zed" often for the terminal letter of the alphabet.
I still wish for phonetic spelling. Consistent, ICAO standard phonetic spelling. But it seems rare on the air.
But when I finally said "kay zed fower ell why" checking into tonight's net, net control read me back as "kay zee fower ell why," so it's not completely consistent. 😀

2024-11-11 02:27:33 UTC

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Sorry for the memory ☹

2024-11-11 00:47:31 UTC

A majority of American voters chose to return the Very Stable Genius to the white house. 😟
Twitter's summary at the bottom of the screen grab definitely nailed it.
(Another tidbit from the tweet delete stream.)
https://social.makerforums.info/system/media_attachments/files/113/461/551/271/332/342/original/b230c2e331d268f7.png

2024-10-20 17:50:40 UTC

I'm even newer to APRS than I am to #AmateurRadio — since I just set APRS up in the past hour or so. I left the new-to-me FTM-350 in the default 1200bps mode. What are the tradeoffs between 1200bps and 9600bps?
I'm a little surprised that I'm getting stations 190+ miles away on 144.39 — or maybe these are digipathed to me somehow? Default digipath selection on this radio is WIDE1-1, WIDE2-1. What's the best place to learn more about this?

2024-10-18 02:38:10 UTC

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I hope it's one of the kind of teensy's that PJRC is still making... 😬

2024-10-18 02:06:05 UTC

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Oh no, I can't order a new DCP405. And that board is very toast.

2024-10-18 02:00:16 UTC

Pretty sure that smoke isn't going back in.
https://social.makerforums.info/system/media_attachments/files/113/325/949/757/337/739/original/01e7b71525b3f265.png

2024-10-16 02:53:32 UTC

Oh no I've signed up for an account on https://lcwo.net what has happened to me‽

2024-10-02 00:35:03 UTC

Shoutout to @npub153e…jwsy on Maker Forums today!
https://forum.makerforums.info/t/the-spice-must-flow-sandify-and-sand-tables/91521?u=mcdanlj

2024-09-16 21:47:58 UTC

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Ok, my memory isn't crazy off for the color. 🎉

2024-09-16 20:31:37 UTC

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Although if you could query MarineTraffic or ShipFinder or ShipTracker for shipping headed toward it and raise it, that would be fun!
Also I'm sure those APIs aren't free, so just an idle fancy. Curt, over to you to install an AIS tracker with line of sight! 😎

2024-09-16 20:27:37 UTC

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I haven't found an API for telling the current status of the bridge. I did find a Duluth ship schedule but many of the entries are "unknown" or "late afternoon" so not something useful to parse to get a reasonable guess at the current state...

2024-09-09 21:11:48 UTC

I, too, sometimes use my scanning electron microscope to debug machining problems.¹
https://www.youtube.com/watch?v=O8txvk5m6VM
¹This is a bare-faced lie. I am neither @npub18h9…chdl nor @npub1je7…x30w and possess neither a scanning electron microscope nor an atomic force microscope.

2024-09-03 02:10:19 UTC

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Thank you much! I use indicator stands with switchable magnets for machining work, and that made me start to worry that I could basically make one of those in a partially switched-off state by accident.

2024-09-03 01:25:17 UTC

I would love some expert physics help for #3DPrinting...
In order to print at higher bed temperatures on my largest #3DPrinter, I'm looking into embedding N42SH magnets in the print bed, which would let me go up to 150°C, instead of the current flexible magnet sheet that is limited to 90°C. Because neodymium magnets aren't actually great heat conductors, I'm thinking of getting small [K&J Magnetics 3/16" x 3/16" axial N42SH (D33SH) magnets](https://www.kjmagnetics.com/proddetail.asp?prod=D33SH ) so that most of the actual contact area is the aluminum bed that conducts heat well. I expect to put the magnets in a square array across the bed.
I can mill precise holes for them with my mill and sensitive depth stop. I think I could affix them with a high-temperature epoxy like JB Weld.
But I don't know enough about magnetic circuits to understand whether they should all have the same orientation or should alternate.
Should they be all oriented the same way?<code>N N N N N N N N N N N N N N N N N N N N N N N N N </code>
Or should they instead alternate orientations?<code>N S N S N S N S N S N S N S N S N S N S N S N S N </code>
Or does it actually not matter unless they are very close to each other?
Any and all expert knowledge gratefully received! ❤️
(If you don't know, please, no need to speculate; I'm pretty good at that part myself ☺)

2024-08-30 19:50:33 UTC

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I spent formative years visiting relatives in Duluth, watching lakers go through the lift bridge.
What a neat addition! 🙂

2024-07-12 03:50:57 UTC

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This was the line of thinking that ultimately led to me getting quotes for a solar install on my house... 😅

2024-07-12 03:39:20 UTC

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I think they *float* at 13.8 but bulk charge higher, which might be compatible with BMS-equipped LiFePO4? I've been thinking of measuring how some of my UPSs charge SLA to see whether LiFePO4 could work.
Unlikely to charge the LiFePO4 at the max rate they could charge at, and I'd worry a bit about whether they could draw more current than the UPS was designed to supply causing overheating, if the internal resistance of the SLA battery were part of the design for the charging circuit current limiting? I mean, that would be a bad design but I've seen the inside of some UPS units that didn't impress me much. 😬
But a 3kva pure sine wave AIO inverter (with MPPT integrated letting you even attach solar panels if you want) can be had for $200-300 and could be attached to smart batteries. That would give you a far better UPS and be less hacky... 😁