mill power table feed

 Ugh.

 After decades of owning a mill with a non-functional power table feed, I have finally embarked on the adventure that getting it working again will entail.

 First piece, because it looked easier, has been the motor drive.  I'm dumping the old, dead 1970s tech in favor of a modern drive with the same capabilities, which is half the size and generates one quarter of the heat as the old one.

 The new motor drive requires two industrial control relays, which I thought I had ordered, but Mouser canceled my order while still showing stock. Their customer service rep seemed clueless and unhelpful.  Mouser is kicked out of the clubhouse.  So are Grainger and Newark as their over-enthusiastic security plugin for the web server is falsing on my browser's plugins and won't let me give them money.  Are they hiding some vulnerability?  Better not risk it!

 There are many other competing suppliers.  Even eBay.

So that rankles because even if I wire it all together including the relay sockets, it's no good without the relays.

 There is other work to be done on this box; the pilot lamp and power switch needed replacement, I had the switch on hand, but not a good lamp.  Those are cheap, I'll get one ordered soon. The box itself needs to get sandblasted (done), acid-etch primed (primer not arrived yet), top coated, then the raised letter parts carefully hand-sanded.

 After that box is done comes the more arduous table feed itself.  This consists of a motor, a gearbox, and an electrical box with switches inside and a pushbutton (for fast-traverse) and a speed control knob.

 The shaft that actuates the switches passes through the oil-filled gearbox.  The oil-filled gearbox which is located on top of the electrical box.  And they did not have Viton O-rings back then, so guess what always happens eventually?  It was a screwball, in-house, ad hoc design.  A good cleaning and replacing the failed o-rings with modern Viton (fluoroelastomer) rings should solve the problem for a lifetime or three.

 And of course, the wire ends need to be trimmed back and replaced, and the electrical components, which are full of oil.

 And I don't think I'll be able to resist sandblasting and coating the power feed assy either.

 I think I have posted a few pictures of this stuff already.  If not, I'll post some.

 ~≈{👁}≈~

minor update on flashlight purchase Fenix LD-22 v2.0

 My flashlight arrived, I noticed some things, and unsurprisingly, I have opinions.

Except for some niggling details, it's housing is more-or-less identical than the LD-20 it replaces*.

Niggling Detail #1: it's no longer possible to stand it on its tail cap.

Niggling Detail #3: I forgot to get my name engraved on it for free, and there is no longer a flat place for that on this housing, you have to settle for it being wrapped around a cylindrical part of the light.  Fun fact: laser engraving does not harm Type III HA - it penetrates the outer HA coating, bleaches the dye out of the dye layer, but leaves the coating above it intact.  Assuming it's done with CO2 and not a fiber laser.  I don't know for sure about fibers.

 That's it, that's all my gripes.

 It came with a Li-ion "AA" size battery pack already installed.  I did not know this because who reads fine print, so I ordered what is now an extra one.  WTH, they are only $13.  In this economy, that's not bad.  It came with all the accessories which are typical - a lanyard, strong belt or hat clip, charging cable for the battery.

FWIW, Fenix's manufacturing is in China or Taiwai, but they seem to be controlling prices well.

 Their offices are in Colorado and their product warehouse is in Monticello, Arkansas - 161 Market St, Monticello, AR 71655 - that's where stuff ships from.

 Their showroom is in Littleton, CO.  I've never been there, I don't know how long that's been there.
I think I might drive down there some time just for kicks.

 The new light emits a maximum of 800 lumens in Turbo Mode.  My old LD-20 in Turbo Mode was good for 160 lumens.  Even 800 is not enough for a light bulb to light a room, but for a "mini" size light, it seems staggering at night.  I'm a "more light is always better" kinda guy - usually - so I am  content.  I don't need my EDC light to be so bright it sets things on fire.  Perhaps a camping light should do that. ;)

 ~≈{👁}≈~ 

____
* I need to dig the old light out of the "raygun parts" box to compare them side by side.

If I'd known we were going to jam, I'd have brought my kazoo

 Gothsigh, grumble, and gripe: Operations stalled.  Kinda literally.

 I haven't messed with the printer for a few days because I am avoidant - like, it's a personality disorder, man.

 What I've been avoiding, until today (until some mysterious switch in my head got flipped the other way) is a filament jam in the extruder.  These were unheard-of with PLA, despite a really aggressive (non stock) tensioner and aftermarket... rims (had to say it) I mean extruder wheels.  I could make it quite tight to overcome resistance in the filament feed chain... like ferinstance when the reel is inside a dryer with stupid filament ports, outside the printer tent.  PLA tolerates a lot of squeezing and knurling.

 I switched over to some new TPU replacement (maybe, we'll see) which is a high flexibility PLA.  If you can see it coming now, why couldn't I see it coming then?

 Yup: I forgot to untension the extruder so while trying to load filament, the too-tight drive rolls squished the PLA-flex into funny shapes all around and near the bourdon tube and drive wheel, everywhere but into the tube.  100% my bad.  A right little mess.

 Unfortunately, with the printer inside the tent, it is a neck-craning pain in the, er, neck, to do anything to the extruder - even just adjusting the tensioner, never mind unjamming plastic bits from a tight mechanism and after five minutes of poking and proding with tweezers, dental probes, and a No. 11 X-Acto blade all to no avail, I walked away for a few days.

 There's always other stuff around this dump our majestic mansion that needs doing, after all.  Like all the things we should have done the first ten years we lived here, when we had money.  Cough, but I digress. 

 I really do not want to move the printer, I especially do not want to remove it from the tent unless I simply can't get this done any other way.

 Now it is time to dig into the extruder again (hopefully I can avoid disassembly) then see whether this flex PLA stuff can even be shoved through a bourdon tube at all, or if it requires a direct drive extruder.

 And where did my filament cleaners go? 😬

 I got the extruder wheel unjammed, still need to remove the bowdens full of filament and empty them.  Around then my leg started hurting again, so I'm not going downstairs to fool with the printer until it feels better.

 I'm also not working on shop projects, both for that reason and because my paint won't arrive until tomorrow, and because fucking Mouser canceled my order for bizarre reasons their abysmal customer service either could not or would not explain.  Meanwhile, they still show them in stock, but they won't sell me any.  I am so done with Mouser.  And why is an $11 relay now $30?!?

 ~≈{👁}≈~

light it up forever

 You like flashlights?  Let me tell you about Fenix Lighting.  This is not a promotional thing, Fenix doesdn't know I exist.  I am not a shill.

 I got into them during the old Candlepower Forums days, when someone was verifying flashlight brands' claimed output lumens vs. actual, measured in a real integrating sphere.  Twenty-five years or so ago, I was sick of my Mini Mag™Lite penlight's pitiful output so I was shopping for a replacement.  LEDs had come along, but Mag Instrument™ were behaving like idiots.  They completely biffed their original LED offerings.  Apparently that plastic focusing cam was their one and only innovation, and it seemed then they weren't interested in any further innovation.

So I was listening to online forums for other people's experiences, and the name Fenix kept coming up. 

 Fenix was the ONLY outfit out of more than twenty, that did not exaggerate their output.  Ok, cool as far as that goes.

 Their construction and materials are top-notch.  Type 4 Hard Anodize has kept my old light looking near new even now.  Hardly any scratches, yet I've used it constantly.

 There is some choice as to switch location, depending on model.  Their hard-coated, toughened-glass lenses won't scratch without a concerted effort and they are nearly unbreakable.

 I ended up with a EDC "penlight" and a bike head light.  They are both adequately bright when turned up, and have several light levels.  Both have seen heavy use and have held up well.  I like how they work.  The bike light has a warning light on its indicator which lets you know a recharge is required, before it will no longer run on high.  When I've neglected it, and gone for a ride when it needs a charge, I can usually finish my ride even with the light on full/high.

 I've had them for more than twenty years now, and had occasion to call in for help once with the flashlight.  Their customer service was excellent.  Other uses have reported similar.

 I've used both heavily for a long time, and it's now time to buy a new EDC "pen" light.  I broke a piece of unimportant glamour plastic off the bike light, but it continues to work fine in all weather conditions, hot, cold, and/or wet.

 To replace the penlight, I picked out another "old fashioned" (long and slender, when the trend has been toward short and fatter because 18650s exist) unit that is basically an updated version of my old light.  

 The new one runs off of either your own AAs (disposable or rechargeable) or Fenix's Li-Ion battery pack.  The only reason I prefer AA format instead of say, 18650s, is to keep the diameter down because I carry it in a Nite Ize belt pouch which can only hold so much fatness before it becomes difficult to unholster. (Nite-Ize - also recommended product) -- no charger needed, the battery pack has a USB-C connector.

(for cylindrical cells of all types smaller than C, I also recommend the NiteCore Intellicharger i4, which will automatically identify the cell chemistry, and will charge any rechargeable battery which will fit into it:

Li-ion/IMR/LiFePO4: 10340, 10350, 10440, 10500, 12340, 12500, 12650, 13450, 13500, 13650, 14350, 14430, 14500, 14650, 16500, **16340(CR123)**, 16650, 17350, 17500, 17650, 17670, 18350, 18490, 18500, **18650**, 18700, 20700, 22500, 22650, 25500, 26500, 26650

Ni-MH(NiCd): AA, AAA, AAAA, C, D

Q: OK, that's all well and good, they make nice lights, I get it, but so what? Surely other makes are good as well?

A: Yes but: 25% Military Discount and free shipping.  And other lights lie about their light output.  Fenix themselves do not crow about this, it's just something the flashlight fetishists noticed.

LD22 V2.0 light: $65.95
ARB-L14 battery: $12.95
military discount: -19.72 (25%!)
shipping: FREE (on any order over $25)
total: $59.18

 They use either GOV-X or ID.ME to verify your vet status.  Recommended company, recommended products.  They are also very popular, so I would not buy their stuff via Amazon or other resellers, just buy direct from the web site.

 ~≈{👁}≈~

ABL - All 'Bout Leveling

 This came up in the Creality Discord a while back, I've been meaning to mention it. problem: "I can't get my bed leveling system to work. I am using a Prusa style sensor with an Ender 3V2. (etc etc) " The Enders have glass beds. The Prusa sensors are inductive, which cannot detect a glass bed. Inductive sensors only interact with metals.
An inductive sensor will operate on an Ender, but you would need to change to a metal bed (ugh, why), or better, change to a capacitive sensor, which will detect any surface. It turns out that a mechanical switch like a microswitch, or an E/M sensor attached to a mechanical switch, has the best accuracy and repeatability of every sensor that multiple people have tested. Amazingly, in this at least, multiple testers' results all agreed. Except for the one fellow who built a horizontal test jig for stuff that works vertically against gravity (WTF OOPS) and sooprahz, sooprahz, sooprahz! All his results for the mechanical sensors were worse than everybody else's... >_< But anyway. IOW, if you have a BL Touch or equivalent, you're good, you can probably stop thinking about bed leveling upgrades. ;)

Just as an aside, I have heard from some folks that were clearly unclear about how ABL works. This is understandable. It can be non-intuitive.

So, let's take my Ender 3V2 for example. It has a glass bed, but I have a mechanical 'BL Touch' type leveling sensor. Not only do we install a physical sensor on the hot end carriage, we must also install a firmware update to the little microSD card that runs the printer (in my case) because we are adding functionality to the machine which it did not have when it left the factory. How the install is done, the firmware used, etc, can vary from printer to printer, and it's off topic to try to explain several different ways, so I won't try.

Once the tech is installed, there is either a new menu or a menu item, in your printer's GUI. You use this to "scan" the bed at a selected number of points. Then the firmware moves about the bed, measuring the height of each point. This creates a new "mesh" which is simply a digital map of the bed's humps and valleys. You could just use this information to manually level the bed, and to a degree, I do this, just to get the bed to within spitting distance of level.

But that is not where the beauty of ABL lies.

Because the mesh is also used by the firmware while printing; it moves the head (or bed, depending on printer - in the Z axis anyhow) up and down as it prints, to follow the real contours of the bed as it is, leveled or not! This is dynamic virtual leveling, it is bad-ass, and you want it.

Even if your bed is so messed up it will never be level, ABL will make that problem go away. Scanning for a new mesh if fully automated, just click on a menu item, it takes only a few minutes, and you should only need to do this when you have moved or bumped your printer, cleaned the bed vigorously, etc. You won't be doing it all the time.

This action is faded out as the print continues and for most prints, it can be faded out completely after 10 or 20 layers. That's usually a simple setting in the printer's control panel, under the ABL menu item. That's how the obviously-distorted first few layers transition to normal, straight, printing. The first few layers may be distorted slightly (in the Z axis) but because they follow the bed's real contours perfectly, first layer adhesion is vastly improved, and that's really what this is all about. Keep spaghetti on the dinner table where it belongs!

So, a bed could be really messed up, to the extent that you couldn't even print on it without ABL, yet with ABL, it will print, and it will print just fine. There are demos of this on YouTube. My own Ender 3V2 has a leveling screw at each corner, but the ABL mesh reveals that no matter how much manual leveling I try, in an effort to get the four corners and center to more-or-less agree, and it's not quite possible.

ABL permits you to have a perfect virtual bed, even if the real bed is not perfect.

Out of all the upgrades and tweaks I've made to my humble bed-slinger, ABL has been the best bargain. 

 ~≈{👁}≈~

If you need to make a complex part, BUT you're in a submarine 500 feet down, you definitely need one of these machines

 I'm not suggesting anyone try to buy one of these, I just think it's an absolutely fascinating machine.

https://www.lathes.co.uk/hommel/
(the site needs white space and he's wordy - too much detail core-dumped at once IMNSHO; it would benefit from a more modular / chapterized approach.)

An extraordinary machine, built to very high standards for accuracy and precision.  By using the base and column to mount combinations of a headstock, tailstock, compound slide rest, T-slotted boring table, rotary table (and numerous other accessories) the assembly could be used as a plain-turning or screwcutting 3.5 inch (90 mm) centre height by 14 inches (360 mm) between-centres lathe, high-speed sensitive drill, vertical and horizontal miller, jig borer, shaper, gear cutter, grinder, engraver, slotter, metal saw or surface table.

A Smithy can only *wish* it had a UWM in its lineage -- these things are special and unique with far greater versatility, precision, and accuracy, vs. a Smithy.  I'd be willing to bet it could be set up to be a drill / milling cutter sharpener.  Just need the right wheel.

The UWG1 (alone, not counting all accessories!) is small enough to fit on top of your shop's beer fridge.  The footprint is smaller than a Smithy.

The UWG2 is the same machine but larger footprint/capacity.  All accessories and tools swap between the two sizes of machine.

 These machines were designed to be an "Eierlegende Wollmilchsäue" or, literally translated, "egg-laying wool-milk-pig" - a machine that could do everything.
(everything that can be done in a tight space, that is - they went onto warships and submarines, even airplanes and ground mobile repair units.)

They are not perfect - warts and goblins are detailed at the page linked above.

There is a German language site with more information, but it's insecure and has eight or nine open vulnerabilities so I can't recommend it. :(

The machines themselves are breathtakingly expensive when they appear on the market at all, and there are a LOT of accessories in the complete tooling set.  Most machines are not sold with everything present.  A single base plate part is on Ebay for $700.  Complete machines can be found more often in Europe, where they sell for $3500 - $5000.  You can buy  a brand new full sized Chinese knee mill with DRO, vise, oiler, everything turnkey, for that price.  You can have it shipped from China to your door for another grand or less.

 So paying that amount for a weird little machine that dates from before WW-2 might be a stretch for most people I know.  Definitely a niche market. :)

And changing it from a mill to a lathe and so on is fiddly and time consuming.

 ~≈{👁}≈~

soldering tips for glorious beauty and great justice

• when putting the iron back in the holder, tin the tip, do not clean it; you want to leave a layer of solder on the tip

• when removing the iron from the holder, clean the tip on a brass wool "sponge", then re-tin it before applying it to the work - do not use stainless steel kitchen scrubbers

• never use wet sponges, this drastically shortens tip life

• never use solder-and-flux "tip cleaners" - the flux is ALWAYS nasty even in name brands - they will shorten your tip life

• never EVER use sal ammoniac cakes to tin a badly oxidized tip - you will condemn that tip to an early death - just get physical with the brass wool; use stabbing and twisting motions. 

The stabbing motions are very satisfying,
you can pretend the brass wool is someone you don't like

• replace factory tips with aftermarket higher-quality tips (Plato, Hakko, etc) which will last longer and sometimes even perform better than OEM, for the same money

• use name brand solder; Kester, Alpha Metals, AIM, Multicore (now part of Henkel/Loctite), Stannol

• use a 'eutectic' alloy, this helps with every kind of soldering, because eutectic alloys have no plastic, in-between state, they are either liquid or solid, so the joint is less likely to move at just the wrong moment as it cools

• buy solder wick and a solder sucker - you may not need them as often if you are doing non-electronic work, but they come in handy sometimes

• make sure your iron has some form of temperature regulation- this need not be a fancy station with a digital display - there are regulated "pencil" irons too

• make sure your iron has enough wattage for the size of material you want to solder;

- 25 watts regulated should be enough for basic electronics
- 35 or 50 watts for wire-frame modeling with thin brass wire or soldering thick wire into heavy duty plated-thru holes in thick PCBs
- 75 watts or more if you're doing stained glass

  How do you know if you have enough?  You should thoroughly test your first purchase immediately and return it (tip clean of course, so it doesn't look used) if it hasn't got enough oomph.  If it's taking forever to heat joints to solder-melting temp, you either need to wet your tip more (dry tips conduct heat into the work poorly) or maybe you actually need a hotter iron.  If making your second iron purchase, consider getting one with adjustable temperature.

Not All Fiberglass Is The Same?

  A few posts ago, I sang the praises of fiberglass scratch brushes. Since using the new one a bit, I noticed the brush end had developed 'split ends' and is now very soft and more-importantly, non-abrasive.

 In other words, it's fucking useless now.  WTH?

 So now I will go buy an Excelta*, which is what I had my original positive experiences with, and I will throw this PoS in the trash.

 I assume the original has a more brittle glass in the bristles, I dunno.  These have gone soft on the ends, and under a loupe, they look like human hair with split ends.  The opposite breakdown behavior from what we want. We want the tips to chip, crack, or break off (eventually) but not to split, ever.

 ~≈{👁}≈~ 

 "There is hardly anything in the world that the Chinese cannot make a little worse and sell a little cheaper, and people who consider price only are China's lawful prey." - J.A. Richards, updated
(it was never John Ruskin)
___________________
* yup, the Swiss wait, California?  Wow.  Anyway the $60 tweezer & $150 pliers people.

Which Wavy? How Much Gravy?

  I am looking at buying a set of wavy parallels; mostly these exist so you can put thin parts in the mill vise which are thinner than a single (1/8 or so) conventional parallel, while still enjoying the benefit of a parallel, ie; aligning the part with the vise ways, and thus (presumably) with the mill's table surface.
Like standard parallels, they come in sets containing various heights.

these are sane curves for wavy parallels

 They are not terribly expensive, depending on whose word you are willing to trust, and how much you want to spend.  They _should_ be easy to make.  Cut out with laser or waterjet, stamp shape with simple tool, heat-treat, stack a bunch of them together in a vise or on a magplate, and surface grind to dimension.  Do a hundred (of each size) at a time.

 So when shopping, I immediately noticed something: most of the less expensive sets have an "accuracy" stated as ±.0002 (over the length of the tool) which is a typical accuracy for both kinds of parallel... BUT most of the cheap sets aren't six inches long.  They are ±.0002 over FOUR inches, not six.  I've even seen a few sets that were three inches long.  I hope it's obvious that they are less accurate than parallels with the same spec over six inches because I'm still in a lot of pain and I don't feel like typing out the explanation. 

 Caveat Emptor. Buying name brand does not necessarily gain you anything; the ones I've looked at are expensive because name brand, but the promised accuracy is the same.

Aside: the acid test for these things - that is, to see if they are any damn good - is all about their spring temper, testing that they can be compressed and will spring back to their original full width.  It goes like this:

1. pick one out, lay it flat on something reasonably flattish
2. measure the wave height - a scale is sufficient, no need to bust out the surface plate and height gauge :) - and write it down
3. stick it in the mill vise and smash it flat.  Ignore it until the next day
4. take it out and measure the wave height again
5. if there is no difference, or only a very tiny (< 1/16) difference, they have good temper and will probably hold up.  If it loses a bunch of wave height, its temper is too soft - if it cracks, its temper is too hard - in either case, return the set to the vendor as defective.

 The other critical feature - how parallel are they really, requires a surface plate, height gauge, and a tenths indicator.

 By the by, the sideways wave shape of these things should be quite shallow, like a shallow sine wave.  Yet I've seen some wild (deep) curves in a few of the cheap ones, even in the Grizzly set, which I suspect will become problematic some day.

Have a look at how deep the curves are
vs. the ones in the photo up top

  It just seems to me that if wild curves were good and workable, all the name brands would have them, since it lets them support wider parts, even parts you would normally need two standard parallels for.  But they don't, which makes me suspicious of the few Chinese-made versions that are deeply curved.  I would avoid those, without real evidence, on general principles and the above reasoning. :)
(and I'll be happy to be proven wrong in this case)

 And another thing: they give you pairs of wavy parallels, but unlike regular parallels, you should never need two wavy parallels.  I asume it's because there are two parallels in regular kits - where you actually need two.  If I ever find a use case that is handily solved with two wavy parallels, you can bet I will brag, I mean blog, about it here.  Otherwise, they're just spairs.

 ~≈{👁}≈~

Craftsman/Diehard "quality"

 Because I've never owned anything but used vehicles, I've had an automotive battery charger since about 1985.  Recently the timer stopped working, which is sorta bad, but I never trust mechanical timers so I was monitoring it and nothing bad happened.

 But I needed to replace that timer. 

(it was readily available on Amazon, probably turns up in a hundred different products including bathroom light timers)

Aside from a heaping helping of spider webs, this is what I found inside...

 The small (about 1in x 1in) circuit board hanging loose from the wires it is soldered to - that's the regulator board for the fan.  There is no regulation or filter provided for the battery being charged.  The fan exhausts the cabinet from the bottom, and thus also fails to blow on the rectifier "heat sink".   Boy was I young and stupid when I bought this thing.

 Changing out the timer was trivially easy, even tho it was held into the panel by some low-profile, tiny-head hex-head screws.  The case was held together by about twenty tek screws.  I wonder where it was made, they sure hadn't heard of Fastener Reduction!

 I was disappointed to find no inductor inside.  Professional grade battery chargers have a big fat inductor (AKA "choke" because it chokes current flow) in series with the output as a filter.

Note that Google's AI knows abso-fucking-lutely NOTHING about this topic.  It will lie to you instead of saying "I don't know".  AI will NEVER say, "I don't know" and that's a huge problem.  Stop trying to use AI!

 I am making an effort, but since Google made AI responses the default behavior, my choices are A) an engine with no depth, like DDG, or B) an engine that wastes tremendous quantities of electricity and water only to lie to me.  I dislike this choice.

 ANYWAY, the battery acts like a capacitive load - you don't filter voltage peaks when your load is capacitive, you filter the current peaks.  Passing current peaks to the battery shortens the plate life!

 Now that I've seen the inside, and that it has a mounting place for an inductor, I may track down said inductor and install it.  Sears sold three versions of this charger; Silver, Gold, and Platinum.

 This was the mid-grade "Gold" unit.  Presumably the pro-grade unit had the choke.  And based on what I'm seeing here, presumably the "Silver" unit just connected your battery directly to the power line. ;)

 edit: So far, I can't find the OEM inductor - if there was one - nor a suitable alternative that I can afford.  There are some perfectly serviceable units for welding supplies, but they cost more than a new, much fancier charger.

 This charger line is so old, there aren't even videos on YouTube about people servicing theirs - it's as if this product line never existed.

 In cheap units like this one, there is only a step-down transformer and a full-wave rectifier.  The so-called charging rates on the selector switch simply change taps to different maximum voltages.  There is no temperature sensor either.  Charge tapering is not managed, it is only the product of the battery's charge coming up to meet the charger's fixed output voltage.  In fact, it doesn't even monitor state-of-charge (battery voltage on an expanded scale).

 It has no trickle-charge or "battery maintainer" circuitry.  It is strictly a brute force machine, and it assumes a more-or-less healthy battery that just needs its charge brought back up.  It will not limit its rate-of-charge if the state of charge is low.

 High charging currents should only be used to equalize a fully charged battery with unequal cell voltages.  This typically happens when the battery has been severely depleted (you left the lights on, would not start the car) and then recharged.  After that, the battery (total series) voltage may be 13V or so, but individual cells can be quite a lot lower or higher.  Charging an unequalized battery slowly kills the plates of the under-charged cells, and of course the total amount of energy it stores is much less than if all cells are working and charged properly.

 So my typical process is to use the 2A rate until it stops charging, then switch to 15A rate until it seems fully charged, then give it a very short equalization charge at 50A for only a few minutes.

 Did I mention you should always disconnect the battery from the vehicle before using an outboard charger?  Yeah, that's a thing. If you go to a high current setting while the vehicle is connected, resulting in an excessively high voltage (16V or more) across the battery and vehicle power bus, you can zorch your Engine Control Module, bricking your car.  So don't do that.

 And the charging current meter is useless due to low readability; I need to replace it with something equally cheap but with a digital display.  Accuracy isn't all that important in this case, it's only used to tell when charging rate is dropping (meaning battery voltage is coming up).

Battery University's excellent page for lead-acid batteries: https://www.batteryuniversity.com/article/bu-403-charging-lead-acid/

 ~≈{👁}≈~