Can you 3D print a Transformer? (Experiment) || How to make a mains Transformer!

[@frac]

Building hint: every 100-or-so winds, put a little tab tape over the wire with the wind-count written on it. If you lose count, you only have to go back to the latest tab of tape.

[@Kevin-jz9bg]

omg why didn't i see this earlier i would have saved a solid hour of my life 😂

[@jaimeenvadoliya7663]

Best idea bro

[@rondeldebbio9219]

Great tip! - could even write on each tab tape to make sure.

[@TheSpatzmann]

I'm so disappointed, expected after 8:50 a "let's hook it up anyway!". Send it to Mehdi.

[@lukahierl9857]

Or andi aka photonicinduction, even if it woud work

[@BadMax02_VR]

i hate that he is so serious he should have done it outside or something or at least at the end to show what would happen

[@ProtoMan137]

@@BadMax02_VR tbf I wouldn't have done it either. Not if I had put so much time into it xD

[@alexreeve]

Until it pops

[@HPD1171]

@@alexreeve I want FLAMES. Aww, I'm disappointed, wheres my hammer.

[@deadbird99]

These two videos about transformers contains tons of very useful info, thanks a lot for that!

[@greatscottlab]

You're welcome :-)

[@robson6285]

Indeed, i agree. Especially these two i was glad he made.

[@moiquiregardevideo]

Thanks for giving all these formulas in one video. It is a great reference, for people who lost their school manuals and are too lazy or cheap to buy new ones. You also clarified why the primary need x turns. As electrical engineers, I learned all that, but the magnetism part was not my favorite at that time.

[@scottwilliams895]

This is one of my most favorite projects/Videos of yours so far!! (And I've watched almost every one!) Fascinating, and really well explained.

[@kestergascoyne6924]

One of the best things about this channel is seeing the use of the Electronics equipment. Learning so much so quickly.

[@tctrainconstruct2592]

5:10 Create 2 secondary coils and connect them in parallel!

[@greatscottlab]

Haha that was exactly my idea as well at that time. But since I would not create perfect windings, the voltage of the 2 coils would be slightly different. When connecting them in parallel, it can create a compensation current which can be pretty bad in worst cases. That is why I did not show it in the video.

[@ortzinator]

@@greatscottlab Is it not enough to have the same number of windings?

[@akjrocks1100]

@@greatscottlab hello sir

[@simontay4851]

If slightly different voltage on each secondary winding is a problem, use 0.1 ohm balancing resistors.

[@GRBtutorials]

GreatScott! And what about winding the wires in parallel? You cut the necessary length twice (or more times), then you wind them at the same time. That’s what I’ll have to do with my SMPS transformer.

[@Asu01]

I expected the 3D printed core won't work due to much less flux density but I'm curious with a 3D printed toroidal transformer because toroidal transformer uses core material with less flux density and doesn't require layer isolation like traditional transformer does.

[@greatscottlab]

Maybe I will try that out in the future.

[@lukahierl9857]

The individual windings of the core-iron acualy are isolated or relay on the oxide

[@RYU47376]

@@greatscottlab How bout R core transformer too?

[@simontay4851]

Not always isolated. Ive seen transformers before where the E and I pieces are welded. There is a weld line along one side.

[@firefly2472]

@@simontay4851 like with microwave transformers. they are all welded. ( well the ones that i did open)

[@j.p.wagner6461]

Your magnetics videos are very interesting, informative and important. The hands-on experimentation which answers real-life questions is priceless ! Thank you for your patience, dedication to-the-art, and sound scientific approach..

[@Alex0474]

*Let´s get started* Those words always light up my day

[@AhmedHan]

Sorry if you said it and I missed, is your ferromagnetic filament conductive? If it is not conductive, you can build up a more idealistic transformer by directly printing a pair of solid EE core (without making a layered design).

[@JonathanKayne]

4:45 the song name is "Home Stretch" by Gunnar Olsen for those who are wondering. Its really hard to find in the KZbin music library...

[@BackMacSci]

I want you to know you are the reason I understand and enjoy electrical engineering!

[@anl2468]

I'm a soon to be graduate electric engineer, with specialization in power transmition. Must of the time i have to pause the video, think about what he just said, diggest it, and then continue. Jajajaja. Eventually i just go back and rewatch it. Love the vids, always learning something. Greetings from Venezuela.

[@user-vn7ce5ig1z]

5:28 - For the first few hundred turns, I was precise and exact. Then I remembered the wise words of Sweet Brown: *_Ain't Nobody Got Time Fo' Dat!_* 😂

[@absalomdraconis]

I'm a little surprised he didn't try to use a fishing-rod reel. Those are commonly available, and do the same winding style.

[@LitchKB]

Interesting - I was hesitating on buying a reel of this as a "better than air" substrate in a 3d-printed axial motor, but it appears to give a moderate benefit - Thanks.

[@absalomdraconis]

You should consider it a sensor & mechanism material instead: focusing fields onto a sensor, building an armature when you want fairly precise spacing, armatures for "fluxgate compases", passive components for magnetic latches, "programmable magnets", part or all of a filter for Hall effect sensors, part or all of magnetic logic circuits, cores for "magnetic 1-wire" access cards, etc. The stuff's just not particularly fit for motor use, but don't write it off without considering it's other possible uses.

[@electronic7979]

interesting study

[@witrc6801]

You are the best in the projects. The second Einstein

[@Ash-bx6kq]

Should have called this one "DIY or DIY: transformers"

[@klausbrinck2137]

The Best !!! :-)

[@sonicunleashedfan124]

Or DIY or 3DP

[@davey2k12]

He only printing the core so shud be called DIY transformer core lol

[@redpheonix1000]

DIY or BUY, you mean? :P

[@sincerelyyours7538]

Interesting! Due to the high cost of isolation transformers in my part of the world I endeavored to build a 100V to 120V 50Hz isolation transformer using an inexpensive 20A 240V to 120V 60Hz step-down transformer as its basis. While disassembling the xfmr I found out why it was so cheap. It had only one winding (autotransformer design) and used 14 ga aluminum wire which I didn't recognize at first because the wire's coating looked just like copper. The xfmr came apart easily enough but I managed to drop the cheap nylon bobbin two feet onto a rug covered floor and it shattered into a dozen pieces, so now I had to build a bobbin. This I did out of 1.5mm FR4 sheets (basically uncladded PCB stock) and while doing so separated the primary and secondary halves into their own sections and this turned out fantastically. I then looked up as many online transformer calculator sites as I could find, calculated the number of turns I'd need adding taps for 105, 110, 115, 120 and 125 Volts (the original xfmr had a 5-way switch for this purpose), added a few extra turns for good measure, and rewound the core using the original 14 ga aluminum wire. When I was done I had 20 or so turns worth of wire left over but left it off so as to not upset my calculations. I then powered it up... and it worked!... but not at 20A. At best it would give three or four amps while humming badly and it will overheat if I leave it on for more than an hour or so. Not to be deterred, I added a two amp circuit breaker to the output, a temperature controlled fan and a 20uF AC motor capacitor to the secondary for a bit of PF correction and it now will work reliably for several hours, but I dare not leave it on for longer than that. Most of the drop in performance I attribute to the aluminum wire but none of the calculators I found had adjustments for aluminum. The unoptimized 60 Hz core material probably doesn't like being run on 50Hz as well. However, it will serve like this on my electronics bench until I can afford to buy a true isolation transformer or locate a used one.

[@EverettsWorkshop]

You know, I had always wondered how one could practically test the flux density value of a transformer/inductor using basic test equipment. Still an amateur at electronics so I learn something from every one of your videos. Thank you for the work you do, I find it very interesting.

[@noweare1]

you need to know the magnetic path length and cross sectional area of the core, voltage, frequency and number of turns then you can calculate B. Path length and cross sec area are located in manufacturers data sheets so your all set. Really just pick a B that you want to operate at and calculate the volts/turn.

[@SLeslie]

It might be beneficial to compare the hysteresis loops of these cores. It can be measured with a scope and a variable transformer and a few small other things. It also would be much more spectacular I guess.

[@victortitov1740]

The hysteresis curve of the 3d-printed core is a straight line for most practical purposes (yes, i have measured it). Its permeability is so low (about 2) that reaching the saturation in high-duty-cycle devices like transformers and motors is pretty much impossible.

[@rizin2213]

Thank you for this video. I have learned transformers through my apprenticeship. Now I'm a Lineman. Never understood transformers to this degree.

[@Beall619]

7:04 those screws were satisfying

[@CraigHollabaugh]

Excellent procedure, result analysis, summary and presentation. Thanks

[@1kreature]

You could have skipped most of the sheets and made it a solid block though. The particles are dispersed so finely that they wouldn't need laminations. Not sure how many microHz you'd gain from that though. Thinner wire and a round bobbin you can spool stuff onto with a drill could work :) Especially for very low current requirements.

[@lonewolfeproductionsbyl.v.9447]

I suggested something similar. Also suggested printing the coil former out of the same material

[@sto2779]

Isn't printing specifically in sheets prevent current loss due to eddy current? Wouldn't a huge lump of block cause a massive eddy current to occur internally?

[@etaaramin9361]

@@sto2779 A bit late, but for those wondering about this, the answer is no. The iron particles are suspended in the plastic and not continuous. The only way you're going to get significant eddy currents from that would be to heat sinter the plastic out (using a kiln at several hundred Celsius for some hours).

[@andremantovani]

Great as always! Remember that the printed parts doesnt have the oriented grains, as the metal one does. This impacts the mag flux.

[@lonewolfeproductionsbyl.v.9447]

I was thinking about that, just couldn't remember the term. As in interesting, and possibly related idea, the 3D printed core has its own form of grain orientation, i.e. the direction in which the filament is printed. Probably doesn't have much effect, but who knows: printing in a pattern that mimics the shape of a magnetic field might have some real effects. Food for thought, anyway

[@robson6285]

Yes, thís teaches a real new lesson. This primary number-of-turns-calculation was usefull ánd rather new, that we are glad to learn from you, great Scott. So... Thanx for making this video!

[@InfiniteWonderz2]

I'll see you next time as well GreatScott!

[@revrev1679]

It works, at high frequency. At low frequency, the impedance a.k.a inductive reactance of the primary winding is too low, because the 3d printed core has very low inductance compared to laminated iron core. As frequency increase, the impedance also increase. xl=2πfL

[@sto2779]

So this could be valid for switch mode power supplies at high frequency? If so what frequency are you thinking?

[@waqasuzair]

Simply amazing!!. Loved how used proper calculation.

[@glebkorenzvit1745]

You made a nostalgie for me. My first transformer was when I was 8. I have made (with father's help) a semi manual winding machine, making windings turn-touch. Never went to maximum B area, less heat.

[@VoidHalo]

lol I made my first transformer last year (when I was 33) out of a nail and some enamel wire. Real sophisticated technology, that. I had 16vac at 60hz on the primary and it wound up melting the insulation on the wire because I forgot to work out how much power the wire could handle. Which at 2mm diameter, wasn't much.

[@AttilaAsztalos]

Ah, the (gladly) forgotten joys of packing the core juuuuust a tiny bit too enthusiastically (ie. "trying to put back in every single E/I that came out of it before re-winding") and slicing straight through the plastic and a few of the inner (typically primary) turns...

[@_micro_world]

for the same behaviour permeability of the core is in charge . great work

[@sa8die]

you gotta watch that "magnetic flux density" that is the key to a successful,.,.i love ur videos!!!!

[@klave8511]

Great video, I love it when creative people do innovative things! Gets us all thinking.

[@MikeGrayM70]

Rob's web "the unknown transformer" is a handy guide for finding specs on used transformers. Thanks!

[@SlavTiger]

I know you likely don't do requests, but is there any chance you could do a diy or buy of an LCR meter?

[@xxportalxx.]

I want to know if this could be used for high frequency isolation xfmrs like for fet drivers or ethernet. Also I wonder if at smps frequencies if it could be used for low power apps like running leds

[@MrStemkilla]

Great video. definitely the first ive ever seen of someone making their own transformer. have you done a switch mode power supply yet? it would be interesting to see and you might be able to get a semi functional 3d printed transformer out of it. still a bad idea but it would definitely be interesting to see.

[@aminemo93]

Is it possible to use iron powder and resine to make a 3d printed magnet ?

[@sto2779]

yes it is possible...

[@craigleemehan]

The ferrous filament composition is much more like the composition a high frequency switching core material; as your experimentation demonstrated. I think you could have better luck printing a solid core for a switching power supply. The ferrous grains isolated by the plastic in the filament would provide the eddy current protection at the higher frequency of the switching power supply.

[@erygion]

Great videos! I'll be watching these a few times and taking notes. Very useful formulas. Thank you!

[@ElectroXa]

Do you plan to try this with a ferrite core transformer ? for example, replacing the ferrite core with a 3D printed core to see if it works in a switching power supply

[@lonewolfeproductionsbyl.v.9447]

I just subscribed (while wondering why I wasn't already). Anyway, I assume the ferromagnetic filament for the 3D printer has some plastic or resinous content, to make it compatible with a typical printer, seeing as they normally print plastic parts. That means the total amount of iron in a given volume of printed core is less than that of a solid piece of iron, or even that of an equal volume of ferrite or powdered iron core. This would have a similar effect as having fewer iron sheets, with plastic or air (which essentially have the same magnetic properties) between them. And this bears out in your observations: versus an otherwise identical iron core inductor, an air core inductor will have a lower inductance. What you have is somewhere between iron and air (because there's "air" between the iron LOL). I've heard about other methods of 3D printing metal, though not exactly accessible to the average hobbyist or maker, which could probably print very functional cores. Now, as to your original question, and the topic of the video, I'd posit that it may I fact be possible, with ferromagnetic filament, to 3D print a mains transformer. Personally, I'd also print the coil former since that would increase the total iron content. But experiments need to be done to determine the size and shape of core that would be required. The end result will be larger than any existing design intended for solid iron sheets. One experimental direction you could attempt, and might be able to make a second video on, is to take that "90 times bigger" approximation you came up with, and choose a core with 90 times the ratings of this one, but calculate the winding requirements the same as this core. Or find a compromise, such as a core with 10 times the ratings plus 9 times as many windings, or 13 & 7, or any other combination that's close to 90 without going to far under (like 11 & 8 would probably work, but with an overall lower output rating). Another experiment to reduce the amount of "air" in the core might be trying to print a more solid core. Try, for example, 3 *thick* Es and Is, solid printed (no honeycomb!). Or even two thick halves, something halfway between an E and an L, so the two stubs of the center part of the core meet in the middle, and hold them together with a pair of rectangular printed frames on top and bottom but not passing through the coils. Food for thought.

[@lonewolfeproductionsbyl.v.9447]

It occurs to me that a core printed out of this stuff might be much more difficult to saturate, if not impossible... Why this matters? Maybe not much these days, but back in the days of vacuum tubes, this would be quite significant. A single-ended power amp (as opposed to push-pull) had an output transformer that needed to be built so it couldn't saturate, because its primary also carried DC current, carrying the output/power tube's plate supply current and thus being its load. They hadda put an air gap in the core so it couldn't saturate, and then make the whole thing huge to compensate for the loss in flux density resulting from the gap. But of course, these operated from around 100Hz to 15kHz, and the biggest (rated for 25W) could be expected to see 80mA on the primary plus 56mA across it DC, and 2.5A on the secondary (designed to match the 4kΩ vacuum tube to a 4Ω speaker). But that's an exceptional example. Still, the end result would have been massive and heavy with an iron core. I wonder if it could be better made on a 3D printer?

[@sto2779]

As your observation, the problem is the filament. It can be easily done making custom filaments. Who knows what the actual percentage of iron is in the PLA, can't be more than 10%, if you saw the inductance of the ferro-PLA, it was only 78uH compared to 3.4H... that is just ridiculously small. If there was at least 50% iron in the PLA the inductance should be at least 1H. The filament scott was using is "proto-pasta ferromagnetic iron filament" and they do not disclose the iron content percentage in the filament (which is stupid). But reading reviews about this ferromagnetic filament the iron content is around 8% (no wonder inductance was 78uH). It can be easily done by making home made PLA filaments doped with higher percentage of pure iron powder, lets say 50% iron and 50% PLA. Better yet using nanocrystalline or amorphous metal powder which is 5 times more magnetically permeable than iron doped to PLA. Buying this proto pasta ferromagnetic filament is really silly for any electrical use. Now that's some real food for thought...

[@jorgea.garzav4650]

at schooll they teached me to use beeswax to reduce, even inhibit noise and noticeable vibration, melt it over the corners and then hit it with a torch, so wax gets into the small empty spaces. Or any heat resistant barnish will sufice, nuts tend to loosen, so its a good measure to avoid or delay those issues. Indistrially they just weld them toogether.

[@researchandbuild1751]

Do the steel sheets coming with the proper coating already? That ferro printed transformer would probably work fine for a high frequency transformer

[@generalzugs6017]

I did enjoy this video and I always learn something new.

[@greatscottlab]

Awesome :-)

[@adarsharao]

The wire diameter and number of turns were always a mystery to me. this video explained it very well. thanks a lot...

[@station240]

What about 3D printing the coil former as well ? It's a more complex shape to 3D print and design. Would like to know if it's possible, as I have a plastic coil former I managed to crack, and had no luck getting a replacement.

[@absalomdraconis]

Try to get some polyester drawing film (it normally gets used like drawing paper, but made from plastic). If you can, then look up how to do solvent welding with it, and you'll be able to do much finer-scale coil formers than a 3d printer would be able.

[@ramlakk1943]

Best one!! Awesome,still waiting for DIY toroidal transformer

[@startobytes]

Can you make a big Video about the Wemos D1 Mini?!!

[@greatscottlab]

No

[@startobytes]

@@greatscottlab why not?

[@greatscottlab]

Because

[@nophead]

Is the ferromagnetic plastic conductive? If not then no need to laminate I think.

[@greatscottlab]

Not conductive. But I wanted to keep its look close to a real transformer.

[@cesarin159x]

Fantastic topic, minimizing hysterisis and eddy current losses would be a challenging task with normal 3D printers and limited material choices. But of course, it's cheaper to buy prefabricated transformers online :) Great video again!

[@quintinkruger9103]

Great video Great Scott ! Just like always !

[@HomeDistiller]

What about replacing the core of a fly back transformer with a 3d printed one? And also 3d printing an E core box and filling it with iron powder? Like the pla core you printed but with zero infill?

[@gendragongfly]

Now I feel really smart for always buying or salvaging all of the transformers I use for my projects 😎 I've always wanted to build one, but it seemed way to complex, guess that feeling was right 😁

[@rustlebruxz0013]

Very interesting experiment and thanks for the info to that german transformer site.

[@douro20]

I believe the properties of this iron filled PLA are very similar to ferrite which is sintered black iron. It works well in motors as demonstrated by Christoph Laimer in an earlier video series.

[@rodrigovenegas4538]

Very interesting video! thanks you for your work. Have you considered make a third video with high frequency transformer with ferromagnetic filament core?

[@gotbread2]

The limiting factor here is not the maximum flux density of the material. The 3D printed material is basicly iron particles with a lot of non-ferromagnetic stuff (the plastic) in between. The saturation of the individual particles is still the same. The limiting factor here is the high magnetizing current due to the low inductance. This in itself would not be a problem but it causes high resistive losses in the copper windings.

[@certified-forklifter]

yeah, 3d printed motor V2 =D

[@ssh.1337]

Great scott! Great video! In the previous days I was working on your DIY soldering station, I need a toroidal transformer . But it is quite a bit EXPENSIVE,when I searched in Amazon india(Actually I am an Indian). So, need DIY TOROIDAL TRANSFORMER

[@thedivinityman]

try the magnetic filament with the white spray paint as isolation between the 3d printed plates.

[@zapindo7519]

when are you going to reveal your book series??

[@Mihail_K.]

Every layer of turns should be isolated with special paper/cardboar or kapton tape or at least covered with a layer of clear lacker! The use of paper/cardboard has one more advantage other than isolation - it makes the winding of the next layer easier. Every layer shoud have roughly the same number of turns. If you don't have the right size of wire you can make 2 identical winding and connect them in paralel, OR just lay 2 wires next to each other, thus doubling the cross sectional area.

[@americanrebel413]

Great video thank you. Ps. I always enjoy your videos.

[@BloodBlight]

I would be curious as the results from a single solid (or as close as possible) print with 100% infill..

[@lonewolfeproductionsbyl.v.9447]

Many of us have had the same thought it seems

[@brandonfranklin4533]

Love your videos! I’ve learned so much from you.

[@greatscottlab]

Awesome! Thank you!

[@AmplifierWorld]

Make a detailed video on ferrite core transformer

[@greatscottlab]

I can put it on my to do list.

[@AmplifierWorld]

@@greatscottlab Thanks sir for your valuable reply. I am great fan of your video

[@jhh-jiynks6568]

I love your channel. Thank you for your work

[@thepcman]

Can you experiment on performance of a 3d printed transformer for a flyback converter, say outputting at most 20 watts from mains? You may take the advantage of power integration tiny switch family for simplicity

[@davidprock904]

Can you please make a mains transformer using the Starship Coil design? And let me know what you have to compensate for!

[@johnperalta9415]

I built my own 220-12v charger when i was in collage using an old transformer laying around lol. It was very easy, i made another with a 3v, 6v,8v, 12v and 24v output for charging Various batteries

[@SpaghettiEnterprises]

Ooooh please Mr. Scott do a gigantic 3D printed SMPS transformer

[@bassblaster505]

after reading this you cant unhear him inhaling at the end of every sentence

[@thewolfin]

Part of the format along with " _Let's get started!_ "

[@sto2779]

Him inhaling is nothing compared to "Luis Rossman" - If you don't know who he is, youtube him. Dude is a guru in Advanced Macbook repairs.

[@bassblaster505]

@@sto2779 lol of course I know who Luis is

[@tomaspecl1082]

Amazing! So helpful and informative.

[@ayman_khuzundar]

A very great and informative video

[@PL-VA]

So many answers to questions that have bugged me for a long time. Thank you!

[@greatscottlab]

You're welcome :-)

[@4DRC_]

Ferromagnetic filament might be good for high frequency and switch mode transformers. Even moreso for RF applications like baluns.

[@absalomdraconis]

Maybe, but personally I'd look more at using it for sensor applications. Much like an iron nail, you can use it to focus magnetic fields, but unlike a nail you can trivially form it into any shape that you want.

[@franzliszt3195]

By painting the steel sheets, is that how you make an isolation transformer safe or, say, safer?

[@havenview]

So what about using the principle of requiring a higher frequency to an advantage and design and run one of the 3D printed versions as a switch mode transformer?

[@IndustrialToolsStation]

when go with higher frequency you will need to decrease number of coil turns

[@bradleydennis210]

you should try to make a linear induction motor

[@perolozac01]

I would assume having a core made with the standard PLA would be effectively the same as having no core at all?

[@vylbird8014]

Well, it'd provide mechanical support of a kind? Actually quite viable at RF, where air-cored inductors are common. My roof antenna works very well indeed using an inductor that's nothing but wire wrapped around a 3D-printed form that holds it in shape.

[@reggiep75]

Hmmm.. I've always wondered if you could print transformer materials or anything relating to electric transformers. Nice, now I get to find out!

[@_servus2283]

is the filament conductive? if not u could have printed the core solid which would have been easier and might have improved it due to fewer air gaps

[@Dr_Mario2007]

I have been thinking about doing the 3D printed transformer bobbins, especially for custom higher frequency transformers (be it the transformer with built-in inverter driver, or just to handle high voltage), rather than using one that's available, as they're still a little bit harder to find. And 3D printed ferromagnetic transformer core may probably do okay with high frequency, beyond 60 Hz, I gotta actually test it on my 3D printed transformer at some point.

[@stevebailey1682]

Can you please provide a link to where you bought your transformer laminations (steel sheets)? Thank you.

[@proxyhx2075]

7:45 Why did smoke appear at the contact points of the transformer and light bulb?

[@HuangLuxuan]

what material did you use for 3d printer? my english is not good enough to tell which word you said sometimes. i think it is good to build a high frequency transformer for a micro controller with such material and a 3d printer.

[@DreitTheDarkDragon]

Do you think different fill pattens can make difference?

[@richb313]

Excellent Video, Thanks.

[@RiderChak]

Yes, i wanna an Optimus Prime.. Haha Sry, I couldn't stop myself.

[@greatscottlab]

Don't sweat it ;-)

[@MCsCreations]

Really, really interesting! 😃 Thanks a lot for this!

[@GGBGameplays]

What about high frequency transformers like the ones used for ATX PSUs? It should work.

[@xureality]

if you don't have the right wire thickness, you can try "hobbykinging" it, using multiple wires to add up to the correct cross section or slightly more.

[@greatscottlab]

Haha that was exactly my idea as well at that time. But since I would not create perfect windings, the voltage of the multiple coils would be slightly different. When connecting them in parallel, it can create a compensation current which can be pretty bad in worst cases. That is why I did not show it in the video.

[@bjrngulbrandsen9440]

Can you print a massive core to and test :)

[@ricardoelectronicsrepair]

small main transformer always pain to winding manually 😂, high power rating ei core should wound stacked primary and secondary to minimize phase shift, minimize air gap with tighter the core to minimize leakage flux, i usually add more turns primary, to compensate fluctuation main voltage up to 250v.

[@Gengh13]

Clearly that filament is not a good replacement for a magnetic core, have you tried using it as shielding? I don't expect good results, but custom 3d printed shielding could be interesting.

[@kaumohlamonyane272]

It could work on mains if you made a switching circuit to control it 😆 DIY smps with 3D printed transformer.