Welcome to another episode of Beyond Unboxing, where Charles buys something almost solely for satisfying his morbid curiosity. Generally, it’s something made of pure Chinesium (except last time) that I’m trying to press into service for something completely unintended, and I’m more interested in a part inside rather than the thing itself.

This time, it’s a little different. What Big Chuck’s Auto Body Center has been missing for the work I want to do in it has been a welder so I can start doing some sheet metal repair on the van fleet in earnest. I began seriously shopping around a few weeks ago for a MIG welder, which would pretty much handle everything I would typically weld. It would have to be at least somewhat shitty, since we paid top investors’ dollar for the company welders, but just not shitty enough such that it makes me want to “borrow” them periodically.

At first I was just considering a used Miller or Lincoln unit with dual voltage input since Big Chuck’s Auto doesn’t have any 240V or 3 phase – I only have 120. Hella butts 120 (several independent 50 amp circuits fed by what looks like a 200 amp breaker) but still only 120, and most welders will power limit automatically. Buying a giant step-up transformer was, of course, one workaround which I didn’t want to consider, and buying a dual-voltage one would also be expandable for any future shops I spider-hole in. Recent vintage ones will usually go for somewhere in the upper hundreds to low thousands, and usually quickly since they’re desirable. But wait….

Hold up, trap. This is me we are talking about here. I’m the king of spending more money and putting more effort into finding a suboptimal solution than just spending money on something that works. Just ask my van fleet and all my robots! Anyways, just buying a welder which actually works has no hack value. I came to this startling realization and decided I needed to do me: Go explore the horrible Chinesium product market and see what the bazaar of the world has to offer me for very low dollar. After all, I could just borrow the company MIG welder for a day and….

So! I spent an evening reading up and studying about Shitty Chinese MIG welders. Heaven forbid I put this much effort into actually studying something that’s useful for society, right? Here’s what I learned!

The Chinesium welder market is generally split up into 3 Gaussian bands for pricing. On the very bottom shelf, you have stuff like this…

 

These things are usually not even MIG, just flux-core only with no gas handling ability. They also don’t have discretely adjustable output power like a knob or setting keys, but just have 2 big switches which rearrange taps on an internal transformer to get you 4 vaguely different voltage and current settings. I’ve used the Harbor Freight Special of this kind before, and they do work with some getting used to, but this wasn’t even worth looking at for me honestly. No, not even the cheesy handheld welding screen was worth it.

Up around the $250 range, you start to get actual adjustability and gas handling, though some are still flux-core only……… but you have to read the description to find out! The torches are still usually hardwired in (this is where I learned the difference between the various welder output connector systems like Tweco style or “Euro” style torch fittings) – guess there’s not money in that product dev budget for a nice chunk of leaded brass.

For this price and less you begin to see the “inverter” based ones – cheaper ones if you just search Inverter Welder will be stick only or a combo stick/TIG machine. These are actually pretty cool in my mind, just I don’t have a use case for them. MIG needs a wire feed system so it’s usually pricier.

And getting close to the “Please buy a used brand-name machine” price range is when you’ll see the whole feature set of inverter machines with adjustable voltage/current/wire speed, gas handling, removable torch, and the like.

I decided to play a game and find the least expensive machine which had:

• Knob- or button-dialed variable voltage and wire speed
• Removable torch
• Inverter-based
• Dual voltage advertised, or at least I suspected could be dual voltage capable.

This last part is important, because I had a sneaking suspicion that these Chinese inverter welders were stupid enough that they would run on 120V even if advertised for 240V.  A lot of inverter machines were being advertised as 220/240V only – which was weird, since the way I know these things should be working, it doesn’t matter. Perhaps the Value Engineering had really made their power supplies dedicated to one voltage or another, or perhaps they are just seeking different markets. Either way, we fast forward ….

…A few days! What? It turns out that this thing is actually Fulfilled By Amazon. Thanks, Jeff Bezos! I was expecting to continue haunting the market for another 2 weeks or so while gently regretting not just getting a usable machine off Facenet Marketplace.

So this here is a “REBOOT” branded … box of something. There’s a crude lineart of a dude welding something – or perhaps shooting his death ray at something. It says Good Quality on it. You know, much like my LED headlights say ‘DOT” on them, writing Good Quality on the box doesn’t make it necessarily true. But, optimism shall prevail!

As of this writing, you can find this thing on eBay for $237.50 with FREE! shipping, which for a box this size is a nontrivial value.

So I’m gonna scoop my own Beyond Unboxing real quick. I actually got this thing so fast that I didn’t prepare anything else, and I was already at Harbor Freight for a company run and decided to unpack it to see if I could get any accessories that fit it right away.

This thing is… deceptively small. The company welders are all pretty beefy, and before that, the machines I’d have access to were not inverter units – they were older transformer ones. It’s in fact so small it can only take the 1kg wire spool size. It’s a very easy one hand lift. Definitely color me surprised and somewhat dubious it contained anything of value.

Alright, and we are on the operating table. This is the contents of the box. The unit itself, a ground clamp, a stick electrode holder, a length of PVC gas hose, and a 1kg spool of mystery meat flux-core wire to get you started. They really know their audience! Free consumable since you probably designed the thing to last as long as the spool does for the guy who buys this and welds 1 thing.

Let’s begin shucking this clam. First and foremost, let’s get this out of the way: Every cable on this – ground wire, torch output, and power cord – is copper coated aluminum wire.

I’m sure it was invented with the best of intentions. It’s light weight, it’s softer and easier to work, and it makes better use of copper conductors at high frequencies because of the skin effect.

Oh, and it’s cheaper. Did I mention it’s cheaper?

For the same gauge, make sure you realize you’re only getting 2/3rds the conductivity. When buying any questionable pedigree wire product, always take a cross section sample and ensure it isn’t bright silver colored, and strip a section and scrape the top few strands with a knife facing backwards. If it also feels too light to be made of metal, it’s probably CCA.

Basically every car audio product you buy on Amazon will use CCA wire to mimic the same gauge copper. This is just fine and dandy if you buy things by nameplate power and never, ever actually need all of the rated amps of a copper wire of the same size.  Listen to the man whose company product dynamometer results were thrown off 30% because we just threw the 4AWG audio cable we wired robots up with at the damn thing and actually tried to push 250 amps through it.

Anyways, I’m sure it works fine for the limited duty cycles and shorter runs (because these included cables and torch parts are NOT the whole 10-12 feet you’d get otherwise!). This is the rant of someone that is very butthurt and traumatized by one specific issue. I literally just finished yelling at a vendor recently for using car audio cable on some custom battery packs I commissioned because they came through silver – fortunately, after a lot more examination, they were just tinned well. I like my wire ｂｒｏｗｎ.

 

The drive mechanism is pretty generic, with fiber-filled plastic everywhere. I was hoping for a stamped metal or at least cast unobtanium drive system, but even low end brand name units have plastic wire feeds now.

What peeved me more was that this torch was hard-wired after all. The huge strain relief grommet made it LOOK like it had a Euro style connector on the output; but alas, it was just hiding the truth.

We’re off to such a good start with this one! Oh boy, this means it will be amazing.

I do have some good news – the Harbor Freight Vulcan series of MIG welder parts, such as contact tips and gas nozzles, do fit this torch. I figured the Law of Chinese Product Packaging Inertia would make this the case.

On the left is what it came with, and on the right are the Vulcan parts.

The gas hose is an 8mm push fitting; no 1/4 NPT here!

I took apart the drive mechanism to see if it would be plausible to convert the thing to a connector (so I can eventually attach an aluminum-dispensing spool gun on it) – not really, all of the cables and gas hose actually just disappear into the bowels. The cable sleeve is pretty much just a bike brake cable sheath.

My goal with taking the lid off was to investigate if there was any plausible reason why it couldn’t run on 120V. It woke up when I plugged it in, but I didn’t install any wire or try to weld anything. Besides, I was curious of what kind of Value Engineering had gone into the other parts. The case removal is easy – just undo all of the sheet metal screws.

There’s two more hidden under the handle too.

And here’s one side of the goods! The drive unit is a little speed-400 type motor, but higher voltage, feeding into a spur gearbox. This thing looked to be an OEM part of some sort you could buy – it’s genericized on eBay and other places as “24V wire feed motor”. The controls are up top, and the big money power is on the bottom.

All of the boards had this name written on them. Arcsonic seems to be the actual brand name/OEM of this unit, along with many others that look like it. I’m glad it was this straightforward!

This smaller board is the rectifier assembly. Just a bridge and some capacitors here, no fancy power factor correction.

The back side of the board – the relay is the gate for AC power to enter the rectifier and DC bus.

The part of this thing that can be called the “Inverter”, I suppose. Most of the time when welders say “inverter based” they mean this kind of buck converter architecture .  In this thing, the rectified AC mains power enters on the left side. It then gets chopped by the IGBTs under the left hand heat sinks to yield a lower voltage. It’s the same topology as almost every motor controller. The large donut on the right is an output inductor to smooth the current ripple.

Actually, looking at the backside of this thing, it’s more properly called a half-bridge forward converter. There is an isolation transformer in the middle between the input and output to step the voltage down in lieu of modulating the duty cycle across a wide range. The exact mechanics of what a half-bridge converter is are beyond scope here, just accept that it made me go “oh, neat” and can be highly efficient.

 

The control board is almost all discrete and thru-hole components. This design must date back quite aways – not being a welding historian, I can only guess it’s lifted from a 90s to 2000s era inverter welder of American or European bloodline. I wasn’t interested in diving into what it did here – pretty much just scanning what the logic power supply looked like.

At this point I was convinced that it might be stupid enough that I can just run it on 120V without issues, perhaps just taking a hit on the maximum output voltage. That’s mostly why I was staring at the power stage, since some architectures will prevent the duty cycle from changing enough to accommodate a 50% reduction in bus voltage; if not, it could be smart enough to error out of it detects a duty cycle increase above a certain limit. The design of the half-bridge forward converter is such that it’s pretty input voltage agnostic as long as your driver circuitry keeps working.

I began putting the thing back together and briefly wondered why a MIG welder would have both a volts and an amps knob – before remembering this thing can also do stick welding. In MIG mode, as I tested, the Amps knob just controls wire feed speed.

Continuing the reassembly! The torch is really, really hardwired in – if I wanted to smack a Euro fitting on it or something, I’d have to deconstruct that whole signal wiring harness to disconnect it from the control board. Not worth it, really. If you wanted expandability into the Chinesium aftermarket, this is probably not your unit – I also didn’t see any easy way to cut a spool gun into the control system. I suggest, you know, buying a real welder.

I decided to go ahead and arm up the mystery meat flux-core spool  and actually get some welding done.

So, Big Chuck’s Auto Body came with something I call “Frank, the I-beam”. It’s a 16″ tall structural beam that used to be 24 feet long. Just an entire I-beam, hanging out and squatting on the floor eating all your leftovers and smoking all your weed, the underachiever. Early on, I hoisted it onto a set of 4 car dollies so I could at least shove it into a corner. I later asked some friends to come over and have at it with torches and cutoff saws – they took most of it to make things like anvils and…. gantry cranes? I didn’t really ask too much.

Anyways, I kept 6 feet of it for… whenever I need an I-beam, or something. Right now, it’ll be welding practice. I was going to crank this thing up all the way and just deposit steel.

Well, I definitely own a steel ball spraying machine.

My history with flux-core welding has been very spotty. I’ve usually just been handed a machine in some field/competition/informal gathering and told to fix this or that, and it was filled up with flux-core wire because no gas or infrastructure to support it and no willpower to change that.

It’s always just made a mess and been horrible, and I always wrote flux-core off as a trashy third-tier welding process.

It turns out, you need to use Electrode Negative mode with it, or “straight polarity” welding. First, that’s a welding industry legacy term, because to everyone else, “straight” or “positive” polarity means something with positive voltage is touching it. Who the fuck knew!?

I sure didn’t – since I avoided the process like I avoid college town liberalism, i.e. once and never again, I never did research into it enough to find out that LITERALLY EVERYONE WHO HAS HAD ME TRY TO USE A FLUX CORE WELDER HAS BEEN WRONG.  You don’t just insert flux-core wire into a MIG welder and start firing away – well, you can, but it would make more little steel balls than weld.

This thing lets you switch the polarity of the torch and the return clamp manually. A more sophisticated machine might have a big ol’ switch on it to do so. Either way, by searching “why is my flux core welder shitty and raining steel balls everywhere” I learned a thing.

Yep, so that vertical line on the right is the first decent looking bead I’ve ever made using flux-core wire.

In my entire life.

You know, past the toxic cloud of flux vaping upwards at me, and the need to constantly wire brush and clean up your weld, it’s actually not bad! I see that, much like people fool themselves into liking India Pale Ales, people also fool themselves into liking flux-core welding. I made several more fine-ass looking beads after this, too.

So, the verdict? I had the machine cranked out to the max on both voltage and wire feed during these tests, and it handled that admirably. It’s obviously not pushing enough power on 120V input to hurt itself, nor to trip a convention 15A breaker. I deposited steel (welding implies it was usefully joining metals) for about 30 seconds straight crossing the entire I-beam width – that was a nasty looking slug by the end – and the machine didn’t throw any angry lights or stop running. In the near future I do want to drag it over to the new shop and try putting an Overhaul wedge together using 240V mains, and see if it wants to go back on vacation.

In the end, this “220V” Chinesium inverter MIG is proving itself quite handy on 120V. Luckily, it won’t be principally welding I-beams together in Big Chuck’s Auto Body. Instead…

 

ＩＴ　ＢＥＧＩＮＳ．

Hey everybody! I’m back with a new episode of Beyond Unboxing focusing on a very unique piece of hardware that I just got way too curious about. In searching for a small American separately-excited (SepEx) motor, I remembered an item I saw on Surplus Center quite a while ago that they seemed to have a lot of trouble selling.

Huh. With no datasheet/manual/pinout available, the odd form factor, and shipping being extremely expensive due to it being heavy, I can see why I think they’ve only managed to sell 5? within the past year. To what other crazy dumbasses, I wondered. This motor definitely had at least 1 of the characteristics I was searching for – it was very American indeed, what with being American made for the American military to drop American bombs – and this will come into play later.

As for being sep-ex, I was at least very convinced it was a field-wound type motor, not permanent magnet. It seemed juuuuuust old enough that permanent magnets wouldn’t have been cheap in that size and not offered as much performance as a big series field winding in the required application – winching something. The multi-pin wiring harness coming out of the motor also indicated a wound-field type to me, since I couldn’t imagine this motor having an encoder or temperature sensor. Perhaps 2 of the pins were a load-holding brake, since hoist and all. But that still left at least three pins!

Not even mentioning the odd lobular shape of that gearbox of course – that got me even curious-er about what went on inside. Just looking at the thing, I counted at least 3 stages of gearing mentally, and with the weight of the whole assembly, there must be some seriously massive gears inside! So I went ahead and purchased one, just one, for merely 40% of the final checkout price as shipping this object was $75 alone. This better be really good…

Aand I’m glad to say that it WAS VERY GOOD INDEED, a journey into a vestige of the big & brute force style of American manufacturing where the product is an engineering textbook in physical form, and containing quite a few pleasant surprises. ＭＵＲＩＣＡ　ＯＮＷＡＲＤＳ! Also, I managed to trace out the wiring for the motor, so there’s that.

First of all – They’re serious. It’s heavy. There was an attempt at shipping it correctly, for sure – the thing was firmly pallet-wrapped to a piece of thick particleboard on the inside of the box which had kinda survived transit. There were several holes punctured in the box also.

I wasn’t worried for it at all, obviously. I was worried more for what it took out on the way down the conveyor, like borderline expecting to pick the debris of someone elses’ Amazon sex toy order out of the motor fan grille level of worried. Luckily, my fears ended up unfounded.

It took… some effort to get this damn thing on the table. That’s an 18″ (0.5m) ruler next to it… the whole assembly is over 2ft long end to end. That’s a lot of little safety wire too, all neatly wound and tied off.

The motor has a nameplate on it showing it was made by the Steel Products Engineerng Division of the Kelsey-Hayes Wheel Company. Looking up the latter, I saw that they did indeed make many wheels, among other things – certainly during any of the 20th century war efforts they would have made military gear.

I back-searched the order number found on the motor and gearbox plate AF33(602)7109 and found some listings for a canceled defense specification from 1982 – so this would probably imply the units were manufactured well before then. Searching out that Mil-Spec MIL-H-25205A(1) showed that it was published as early as 1960. And searching the NSN (NATO Stock Number) 1730-203-8712, in the form of 1730-00-203-8712 yielded a 1963 date. So it could mean these things were built around the Vietnam War era.

Most of the info I could find was buried behind spammy paywall websites that aggregated mil-spec info. I wasn’t in the mood to research out the history of this damned thing, just to take it apart and see if I could use it for unintended purposes. I’m guessing after these were all decommissioned, they got stuffed in a warehouse in some recently-closed Air Force base before making it onto the surplus markets. Anybody who has more information on these, or if you’ve used one in real life, is welcome to tell me more about them! Would you recommend them to a friend?

The nameplate on the gearbox housing yields about the same information.  Based on my understanding from some light research, these were hitched to planes to lift bombs into position, but the planes did not carry them along for the ride. The numerous quick-release features and handles on it do imply this object was intended to be quickly moved in and out of position. I’m guessing the whole operation looked kind of like this, but I must balk at the unwieldiness of this device for such a purpose. Maybe 75 pounds is only heavy to me.

It is quite adjustable, however. The unpainted aluminum casting at the front pivots if you pull a pin, and can lock into one of six positions. The base has a pullable locking pin also, as well as four riveted shouldered sliders (two rivets visible above) so it was definitely designed to slide into something and lock in, then be removed quick.y

 

It also comes with accompanying toys – the tackle block and its accompanying 8-tooth ball-bearing-mounted #80 hard chrome plated sprocket, and its mating friend, an extendable wrench which fits into a cavity in the sprocket for when you need to give your bombs some manual assist. The fact that a #80 chain is the preferred hoisting medium still boggles me.

Let’s start taking this thing apart! First, there’s a spanner nut that retains the quick-release assembly which needs to be unscrewed. Absent the correct tool, I just used a needle-nose plier. The quick-release assembly has a 7-tooth #80 sprocket inside which has a splined bore for being driven by the gearbox.

There’s the drive sprocket. The chain enters through the vaguely H-shaped guide slot in the bottom of the quick release, and is fed into the sprocket and kept from losing contact by guides (and probably by virtue of being huge).

There’s a rotating cover of some sort which is retained by a pin – once the pin is driven out, the cover is removed and the sprocket is no longer being detained and is free to leave, thank you very much. Now you have a 7-tooth #80 sprocket to play with that fits on that specific type of splined shaft, which will be removed in due time!

I continued removing all the ‘jiggly things’ so they wouldn’t get in the way later. It has some other small clips and handles that all are held in by mildly press-fit pins.

Oh, and safety wire. Did I already mention all the safety wire? Everything is safety wire.  In beginning to remove the motor for my appraisal, I had to spend 5 minutes cutting and extracting all of the safety-wired screw heads!  I noticed the screws themselves were barely tight for the most part, with their only saving grace being safety wire. I assume this is not actually standard practice in the aviation industry…

All of the bolts are US threaded – they are generally 5/16″ thread, using a 1/2″ hex drive. Here we go! About to crack the motor off…

And let there be PEANUT BUTTER. There is a heavy grease packing inside which can only be described as peanut butter – it’s everywhere, and it smells straight up pre-EPA carcinogenic. You know that “Old Electrical Equipment Funk”? It’s that, but on anything it touches. I ended up digging a lot of it out with shop towels later and throwing it ot…. but part of me regrets it now and wants to keep the grease of the next one(s) I buy (if I do) in its own little jar for future generations to appreciate.

But here we see where I have already made wrong assumptions about this thing. I assumed it was a direct drive off the motor into the worm gearbox, or at most 1 stage of gearing. However, looking inside at this point, I see at least three stages of spur gears.  It’s interesting to note that I haven’t found a single molded plastic part yet – everything is rubber, phenolic, or metal.

Here is the motor by itself. I’m going to dig into this thing a little in order to find the pinout of the 5-pin circular military style connector, in the process discovering the type of winding it has – whether it’s series or shunt wound, or a seperately excited motor like I want.

First, four tiny safety wired!!!! screws need to be removed for the rear cover to pop off, which only houses a fan.

You may be wondering what that little “Westin Elevator Shaft” contraption is on the side. It’s a captive hex shaft which has a socket on the other end that mates to a hex stub in the spur stage of the gearbox. It seems like its purpose is to allow hand-cranking of the gearbox through the reduction the motor sees – presumably while your buddy is standing on the end of the manual tackle block tool also, so you can hoist bombs even when the power is out.

Another set of SAFETY WIRED!!! tiny screws and a shroud that covers the brushes is released. This doesn’t affect the brush holder – it only allows you to see into the ventilation holes. I’m guessing this motor might come in several flavors including open (like this) or enclosed/fan cooled (like it was before I cracked it open) depending on options.

The fan is retained by a single nut, and removing it exposes the part of the motor which I suspect was designed last.  So here’s what’s going on:

• The outer ring of 4 nuts hold the whole endcap onto the tie rods that run the length of the motor. These are structural to the motor. They’re #10 thread, so a 3/8″ hex drive, except one by the Westin Elevator Shaft which is a “thin pattern” hex nut using a 9/32″ hex drive, probably since there isn’t enough space for a bigger nut.
• The inner ring of 4 nuts retain the brush holder onto the endcap, and are #8-32 nuts, so a 11/32″ hex drive.

So there you go: 3 tools to do this operation, all within a few 32nds of each other. I was confused as hell about what was just painted over or not and if i was really seeing things or there were #8s and #10s in close proximity. ‘Murica

 

While I was undoing the endcap, I also unfastened the giant die-cast junction box and unscrewed the circular connector to try and find out if there were obvious armature/field wires. They all disappear into the motorial abyss, so I’d need to keep exploring.

Continuing with the theme of “no plastic anywhere”, all of the wire in this thing has braided insulation!

So I’m a wee bit confused on the order of operations needed to assemble this thing. I clearly did it the wrong way, which is to remove all of the endcap nuts at once and yank. The inner ring of nuts retains the brush holder and also locks it in a certain brush timing, which I will not be able to recover exactly.

What I think is the correct way to disassemble the motor appears to be removing the tie rod nuts (outer ring of nuts) and then removing both the armature and the brush/endcap assembly at the same time. That way, the brush holder isn’t disturbed, and since it’s a wound-field motor, you’re also not fighting magnetism to do so. Something to keep in mind for next time! I’ll show how to disengage the armature in a minute.

This brush setup is quite something. The brushes themselves are circular arc shaped and they pivot on little arms, instead of the traditional inline coil spring setup. Wonder why they did it this way? You potentially get more brush life from the small amount of space the other springing methods would take up, I suppose.

To pop the armature out, use a thin 1/16″ pin punch to drive the pin out of the pinion side. The pinion, it turns out, lives on another spline and the pin’s only for axial placement.

Then you yank. That’s a real pretty armature – it’s wound almost like a starter motor (which I suppose it will share a lot of intermittent-duty high-power lineage with).

Of note, it has a large flat steel faceplate. This is related to the next photo:

First of all, field windings and brush terminations! This allowed me to back-trace much of the 5-pin connector. I determined that the motor was indeed a separately-excited (Sepex) motor!

You see the fibery-looking pad at the bottom? That’s a phenolic brake pad. It’s spring loaded upwards naturally, and you pull the little pin on the right to engage/disengage it. It mates with the steel disc that is on the armature. When it’s engaged, the motor shaft is hard but not impossible to turn. It’s likely a load-holding brake for the motor and is there more as an extra precaution – unless that worm gear stage is very high helix angle, I can’t imagine the motor contributing all that much to load-holding versus the worm gear.

Repeat after me: “Reassembly is the opposite of disassembly.” I discovered that my “correct way” of disassembling the motor was in fact not going to be possible – there’s two attachments to the brush holder that are screw-in and must be obviously done so while the brush holder is not mounted to the endcap!

So the way I did this reassembly was armature, then brush holder, then the two screw connections, and then the endcap (then thereafter the fan shroud and so no). As for how the factory made sure the brush timing is correct…. hell if I know. I did my best by visually inspecting it through the vent holes.

You know what? Just don’t take the motor apart and take my word for it.

Since the motor was really my agenda, I decided to do some basic characterization of the motor. For my sepex application, I would like to know the field resistance, armature resistance, and ideally the magnetization curves of the motor – no-load voltage (out) versus field current for several different input speeds.

The problem was I would have needed a controlled way to spin the motor up to around 10,000 RPM, so I didn’t get any of the magnetization curve data for the time being. I found out that on its native stated specifications – 28 volts applied to both field and armature – it wanted to draw 6 amps spinning no-load at 9,200 RPM. For such a big motor, 9,200 is really fast…. but the 8,000 RPM @ 44A specification on Surplus Center made more sense.

I also solved the armature resistance to be 0.04 ohms and the field resistance to be 10.1 ohms. This is one hell of a motor – albeit only for a short period of time, which sounds perfect.

all together now… what the fuck is he building now that needs this specific motor? doesn’t he design motors for fun?

To summarize this section for now – here’s a pic of the circular connector showing the pinouts I discovered.

That ought to fix all the buyer questions on the Surplus Center website, and hopefully make this thing a little more useful if you have a #80 chain hanging around that needs something to climb up it slowly.

But the story doesn’t end there. Oh, it’s just beginning. There was still 30 or so pounds of gear that I haven’t even opened up yet.

I’ve already found that my assumptions about the input stage were wrong. What ELSE don’t I know about this? Let’s remove the 25 miles of safety wire that hold the back gearbox cover plates on.

I actually decided to work forwards from the motor and start on removing the worm gear stage first, since I got very curious about what kind of worm gear it was which they’d still warrant a load-holding system on the motor in the form of the spring-loaded brake. The six inner screws release a cover plate for the bearing of the worm wheel axle. The outer six safety-wired screws hold the entire endcap on; it’s a mild press fit, so be prepared with a sharp paint scraper or knife edge to do the initial release.

The worm gear system is now exposed, but it’s not yet removable since it doesn’t have enough slop in it to wiggle past the wheel past the worm.

The other side of the worm wheel axle is just the large back-side cover. Time to take all those screws out and start paint-scrapering to release the press/grease fit!

First off: Holy crap, that’s a lot of peanut butter. Second: Holy crap, that’s another entire intermediate stage I wasn’t expecting! Third: Holy crap, those gears have stub-form teeth! I’ve only read about that in engineering textbooks of my bunny days – never seen stub gears in real life before.

Once this back cover pulls out, by the way, the worm wheel just falls out the endcap side (bottom in this photo).

The worm wheel is kept in place by the compression provided by the spanner nut, but power is taken through an involute-splined hub. Notice the small gear stage next to it. This is a mere 1.25:1. The gear at the bottom of the worm wheel axle is 12 tooth and mates with a 16/12 tooth cluster gear which does the final mate with the large output gear. I must wonder what type of packaging concern or ratio fine-tuning warranted this intermediate stage when you theoretically could have tuned the worm gear or output gear one way or the other slightly.

The worm stage is a double-enveloping type, also called a globoid worm design, for maximum strength and contact area. This thing has just been an engineering textbook in a peanut-butter filled box so far; it was actually quite pleasant to see again, given my recent forays into electronics and shitty vans.

I sprinkled the final drive out of the casing, only to discover….. more peanut butter. Go figure.

What was also cool to see: Inch-sized big-bore thin section bearings. These days, the dominant bearing is the metric single-row series (6002, 6200, 6801, etc.), but there is not a breath of metric on any of this. The bearings all were crunchy – unsure if it’s due to aged and dried lubrication or just specified to be a lower uniformity/finish grade, but I’m going to yank them all off and keep them.

After I cleaned the peanut butter off for the most part, here’s the final drive. The output shaft isn’t actually retained by anything but the back plate – once it comes off, the shaft will fall out. It also isn’t carried on its own bearing, depending on the distal bearing found in the aluminum mounting assembly with the swivels that I removed first. So the green gearbox wasn’t ever supposed to live on its own either.

There was still a worm gear stuck inside and the 3? stages of initial spur gearing I haven’t discovered yet, so back to the other end we go! The same procedure is used on the motor side: cut off all the safety wire and just start unscrewing. This side has some dowel pin alignment mates which are more press-fit than the rest.

Aaaaaaaand more peanut butter. By this point, I’ve almost half-filled a 44-gallon rolling trash bin with towels full of peanut butter stains.

The setup didn’t make any sense to me, as I was clearly spinning the motor pinion’s mating gear by hand but seeing two different rotation speeds. In fact, the hex shaft which couples through motor into the (missing) manual crank handle is geared up from the handle itself, but at a different ratio to the motor which is geared down in two stages. They put a complete independent gear path in here just so you can spin it by hand – I’d like to think it was informed by how much torque it was comfortable to keep applying versus how quickly your arms get tired from cranking.

But it was probably because steel was basically free back then.

After another container truck left for the JIF factory, we expose the final boss of this gearbox: the screw holding the input gear on.

Actually, no. It was in fact easy to remove that screw, but hard to remove the two gears in front of the worm input gear. They’re just press-fits with bearings ,which I had to “three phase screwdriver” pry the upper right (motor input) gear out, and slide hammer the hex shaft gear out (attempt 1 with a vise grip is shown…. attempt 2 is hooking my slide hammer onto this vise grip) trashing the tiny inch sized angular-contact bearings in the process.

 

F :(

 

The input pre-duction has been freed!

….and there are more screws. And more safety wire. 2 health bars? Nope, this thing’s had like 20 extra lives by now.

After that gets undone, the worm gear pops right out! Hurray!

Here’s the final gear count: Seven, each intricately engineered and machined, with polished teeth and edges. Go watch some worm gear machining videos and then talk to me about how sweet this thing is. I’m not sure how I can even use any of these gears outside of the box they came in, because I sure as hell am never going to make the worm gear fit correctly in anything again. The temptation of bringing Cold Arbor back, though, went up several-fold after doing this surgery.

So what’s the ratio from the motor to the big 7-tooth sprocket? The input stages are made of two stages of 54:14 (14 tooth pinion on the motor, a 54/14 cluster gear, and 54 tooth worm shaft input gear). The worm stage is 30:1. Then you have the 1.25″1 intermediate stage (12 teeth on worm shaft onto a 16/12 cluster) and finally the 36-tooth output gear. That’s a total of 1673:1 and some spare change.

I’m inclined to say that this device is really best kept together, maybe with your own assembly in place of the swivel mount, and using the motor as-is also; maybe doing some work to adapt the input shaft to your own motor.

There’s so much excess it’s a joy to behold: In its day, steel was free, labor was cheap, and China wasn’t a real place.

alright, so what the fuck are you building that needs this precise kind of motor, the more American the better?

All will be revealed in due time, but it’s exactly what you’d expect. I’d like to collect some magnetization data on the motor soon, so I’ll report back in with its operating characteristics at several voltages and speeds. I’ll likely end up purchasing another one GREAT, MORE PEANUT BUTTER and making a face-to-face dynamometer to collect said data (maybe not full dyno curves, but at least the bemf-versus-speed info) since the best way to characterize a motor is to drive it with itself, in an electrically masturbatory loop of power.  I’m thinking of how I’d incorporate the rest of the gear stages, but it seems unlikely with the ratios I can arrange them in. All I can really say since I don’t have a definite timeline due to my startup-baby, is that it will bring some interesting new-old tactics into a game with an established meta; it won’t win anything, but will be glorious while doing so!