Easiest MOT Salvage Tutorial Pt.3

Video 3 of a series showing how I disassemble Microwave Oven Transformers (MOTs). This video shows you: 1 - How to clean up the old core, 2 - How to create a bobbin to wind coils, and 3 - How to put it all together. You should be ready to make any MOT project after this.
Based on feedback, there may be a Pt.4 later, to include FAQs and things I missed or explained poorly.
Part 1: • Easiest MOT Salvage Tu...
Part 2: • Easiest MOT Salvage Tu...
Perhaps these videos will help you save money on tools or projects, or even make you a little bit of extra money off of the things you make with them. If you live in an underdeveloped country and are looking to start a business but can't afford (or even have anywhere to buy) the tools to startup but have access to junk, this is for you. If you're looking to buy nice tools later, having some trades experience with a cheap one can help you know what features you'll want.
Upcoming Projects: Spot welder, stick (arc) welder, plasma cutter, variac, hydroxy torch, carbon arc torch, arc furnace, battery welder, car (or other) battery charger and more.

[@williamwellisch960]

Please make more videos, ignore the haters! You have a refreshing sense of humor(rare in the KZbin world). I had fun watching your vids and was disappointed there weren't more of them. Subscribed!

[@rikkybora7895]

After watching your 3 MOT videos, I feel almost a professional in transformer rewinding. The downside, the pack-rat shall grow even more in me going ahead.

[@DavidColl78]

you`ve got the best teaching attitude / make-do video I`ve ever seen. Bravo ! Hope you continue this way, these MOTs were very fun to watch with 100% learning material

[@tomatohodson]

I love the sped up video and power tools sound really cool when played back like that.

[@jamunizca]

Excellent video! You give a tremendous wealth of information in a short length of time. I look forward to seeing more of your videos.

[@MattsAwesomeStuff]

Thank you for expressing all the things I tried to ensure I did, when I made this video. Very kind of you to take the time to say so.

[@MattsAwesomeStuff]

Thanks Nate, that's encouraging. I have many in progress but they keep not being a high enough priority to finish. I like making the actual projects, not editing videos for countless hours, so, it's hard to slow down and document things. It's such a big hurdle I've avoided even chipping away at it for a while. I'll get on it some more soon, I do want them done.

[@sonofsam22]

I think the wait is worth it, your videos are enjoyable, FULL of information, and just plain awesome! You've certainly earned a fan!

[@The-Bloke]

This is hands down the best MOT tutorial I've seen, and I've just watched several. Thanks very much for this comprehensive, clear and concise guide! Sad to see you never made many more videos. Hope you didn't end up zapping yourself with 2KV or something like that :)

[@markm2302]

Awesome video ! I would love to learn more from you. Hopefully you will make more . Thank you for taking the time to help others.

[@eagleeyes6972]

very good video with good explanation you are really good at showing and teaching great thanks and well done

[@CaseyNixa]

Cool! Looking forward to the spot welder video. I could use a bench top spot welder to build battery cells for RC cars.

[@NoxuzBlog]

dude thanks a lot this is by far one of the best videos i have ever seen... love the humor!! keep it

[@MattsAwesomeStuff]

+Alok_Deherkar - This really deserves it's own video, I just haven't finished filming it yet. In short... you can wire the primaries in series or parallel. Both work, as long as do the correct thing with each of them depending on the solution you pick. For your situation, I would wire the primaries in parallel, but their phases must match (all heads and tails each together if coiled the same direction (clockwire/counterclockwise), reverse any that is coiled backwards). For the secondary, again, you could wrap them in parallel or series. I recommend series. So for a welder if you're looking at 30v and 3 transformers, size your wire so that you barely fit 10 turns on each core. If you voltages add wrong (10+10+10 = 10 instead of 30) then one of your secondaries was put in series backwards (10+10-10 = 10), just swap that one's head for its tail. Make sense?

[@ClevelandRocks216]

bruhhh! I watched probably close to a hundred of these types of videos. not to mention, I rewatch the good ones (like this) countless times. I came across this one today. already watched the previous 2, and I subscribed etc. when looking for that spot welder video tho..well, I cant seem to find it lol 8 years so I'm guessing you changed your mind? this is amazing content, and I love the humor. bout spit my coffee out, when you started painting your nails, in the one..thanks homie

[@selador11]

Subscribed! Dude, you present tough material in a way that is easy to understand! Thank you.

[@MattsAwesomeStuff]

To some degree, yes. It will also make your volts sag more heavily under load (true of using any shunts) which is generally undesirable. Shunts don't limit current in a "leave it alone until it hits X" useful way. They muddle with it along the way. The better method is simply more primary turns. If you want one that stays cool in ambient air, use 2 primaries in series (240 turns). But note you won't have much room for 2ndary unless you replace the whole primary with thinner wire. Many options.

[@sexysallyUK18]

Thanks I enjoyed all 3 parts. Looks like a lot of people skipped parts 1 and 2, hence lots of Q's that have already been answered in the videos.

[@redpillftw]

Awesome series! Hope to see more in the future!

[@PrinceWesterburg]

Nice editing with a sense of humour. Love the sped up footage with motion blur and in-key sound, would like to know how you did that actually! :o)

[@Tocsin-Bang]

Probably the best MOT series I gave seen!

[@MattsAwesomeStuff]

Stephen Cook - it's because I was the first, everyone learned from me. Thanks for the kind words.

[@Tocsin-Bang]

Having spent most of my adult life as a teacher and a trainer, I have to say you are extremely modest. It takes skill, knowledge, planning and understanding of your audience to do this so well.

[@dylanm36]

Very valuable set of tutorials, must have taken you a while to produce. Thanks, it's appreciated :)

[@roberttwiss7514]

It took me a while to find the information you provided, great job, thanks.

[@smokyatgroups]

Thank you for making these videos your tips and expertise are great!

[@billybonewhacker]

this series was obviously a lot of work. and i appreciate it.i have a book called quick and dirty transformer design. which has all the math but i Never thought about using mots.i build homebrew tube sw radios and transmitters.and tubes need higher voltage.i may try this cuz formers from radio daze are like 100$!. ty

[@georgekhaziran]

Matt you got me hooked THANKS !

[@carlgradolph9676]

Best video I've yet seen on MOT rewinding. Pulling wire through an assembled core (as many videos recommend) makes no sense to me. Not only is it inefficient and a pain in the ass, it also poses the threat of nicking the insulation on the wire being pulled. Why not take a little extra time to disassemble the core, because after all, tearing sh*t apart is fun, right? People who have decided to tear apart a microwave oven in the first place should understand this intuitively. Taking the extra time to build a bobbin to wind the new secondary is a good idea too IMO, because building stuff is almost as much fun as tearing stuff apart. You do a good job of discussing risk factors and presenting the necessary math and physics in a bare-bones manner. Based on that, I have subscribed. Looking forward to future videos.

[@MattsAwesomeStuff]

I think many people are looking forward to future vids, but it's been 6 years and I haven't gotten off my ass to film any. Some day I may start a Patreon shame campaign where your donations make me feel worse about not making videos. I'm not sure it'll make me make more videos, but it would make me feel worse about not making them.

[@carlgradolph9676]

Matt: I've produced or crewed on hundreds of hours of video (none of it available on KZbin), so I fully understand how much time and effort goes into the process. To make a quality video, you have to have equipment: Lights, cameras, microphones, props... Plus, you need to have some kind of script, or at least some rough plan for presenting your information. Then, you gotta shoot some raw footage. A lot of it. The basic rule of thumb I was taught is that it takes one hour of raw footage to make one minute of finished product. Having shot a bunch of video, you then go through the agonizing process of editing, wherein all sorts of choices must be made (including the decision to re-shoot some scenes that didn't quite present the information in a meaningful way, or when the lighting wasn't right, or the audio dropped out, or the cat walked in front of the camera...). Few KZbin viewers are likely to understand or appreciate this. Many just want free information, and some are so lazy and stupid that as soon as they latch on to somebody like you, they expect you to design a 7000 watt power supply for their ultra-bass amplifier for free! So I support your idea to launch a Patreon channel (or whatever it's called). Can't say at present that I will fund it, but you might be surprised to find some very generous backers out there in the aethers. That's what makes the World Wide Web so exciting, right? Best of luck.

[@mindofmadness5593]

Wanted to say thanks. Funny I've torn a lot of these apart over the years. As a kid the "E" made goodthrowing stars. As an adult the wire made good salvage. I knew what a transformer is but it never came together that I was tearing one apart. It was sort of like all the Doohickies one finds on a circuit board-neat to look at but not knowing if they have any further use they get junked. Need something that walks people thru the basics of what those things are to desolder an reuse.

[@johnconrad5487]

I watched all three parts. very well done. thanks.

[@RileyPorter]

looking forward to your spot welder vid! Great work.

[@waltpett2364]

Clever and funny. The best video on You Tube. You should be in show business.

[@MattsAwesomeStuff]

Yes. ... I just did. You just watched it. Use the specs you need for your lights/fountain project, pick your low voltage, follow the procedure in this series of videos.

[@selador11]

I should be able to easily use standard single strand 10 to 12 gauge romex for the secondary winding. Should be plenty of room, with lots of room to spare. And it should then carry enough amperage to keep the drill supplied. All this, I have gathered from the info you provide. And thank you very much for that. Now the questions. (Continued)

[@grahamchiz6076]

Best one I've seen. Thanks.

[@MattsAwesomeStuff]

Well that's very kind of you to take the time to say. Thank you.

[@two_number_nines]

great video man, but i see your thin core transformer which i also thought of, but after some thinking i realised that this way you overload the core, because you double the magnetic field of the primaryes, but keep the cross section the same

[@parkerd2154]

Hey man, great video. Now time to upgrade to a real channel icon. YOU'VE EARNED IT

[@MattsAwesomeStuff]

@konstantinNeo Beryllium Oxide is only present in the tips of the magnetron CRT, and even then is touch-safe unless you grind it into powder and inhale it. It will be either pink or white and looks ceramic. Safe to handle and cut off above or below (mates to steel or copper), just don’t go grinding into the clay part. Unless you’re after the copper in the magnetron (underneath the heatsink fins) or the 22g tungsten filament there’s no reason to strip the magnetron down that far.

[@pietzeekoe]

Can't wait to see it. Subbed

[@MattsAwesomeStuff]

1 - You got it. The drill motor has resistance. Amps = Volts / Resistance. So, if you give it the voltage it's designed for, and its resistance is what it is... it will use the current its designed for. If you give it more voltage, you'll get more current (it'll spin faster... you can probably cheat and get more power this way too, mostly-safely). 2 - First, when you turn AC into smoothed DC, you get 1.4x the voltage. So, 14.4 becomes 20. That's probably fine. (I screwed up this formatting...)

[@mcyammerer2262]

Good stuff, did you make the video about the spot welders? I'm curious to know the kind of voltages that work well for welding battery tabs. I'm thinking between 2 and 5, possibly making up to 3 stages for low med and High voltage.

[@MattsAwesomeStuff]

Yes. Still making it 60% filmed. My big project is an electric bike from junk which I've filmed as well, and that's occupied both my studios (basement and garage) and it's a pain in the ass to clear everything out and set it up for a different project. The bike has taken way longer than I thought. Spot welding primer: Make a 1 turn secondary. Copper tips, clamp. Done.

[@phanzor9032]

Why did you stop making videos? You great videos with the most detail I have found on actual scientific explanation. I urge you to continue making them.

[@MattsAwesomeStuff]

+Nathan Anton I didn't stop. I have many scripted and half filmed, just not much to show. I moved, didn't have much room for a studio. I didn't want to film anymore with such a crappy camera (480p) and didn't want to spend money on a good camera (1080p). I gave lots of project advice to some other KZbinrs who now have hundreds or thousands of times more subscribers than I do now, and frankly, their production values were better than mine. HOWEVER. I have a new camera. I have recording space. And I really want to make more videos, so, hopefully I find the time.

[@phanzor9032]

+MattsAwesomeStuff Cool! I look forward to seeing them in the future.

[@arthursmith3154]

Thanks for the video you answered a of questions that I had. keep the video comming

[@MattsAwesomeStuff]

@tomatohodson : That's just it. I compress with "Maintain pitch" so the frequencies don't get chipmunky. And in editing it's fine. But above some speed, they mute entirely. The only fix is the opposite, let it get high pitch, then try to guess at how far to bring it back, and even then it sounds muffled. Currents: 1 amp per watt. ~1000A. I cover it in the video (scripted, so far unfilmed), cast alum is fine, but you lose 40%. So, 600A. Don't worry, there's a free copper method.

[@8990nathanm]

this was awsome man! I hbope you make lots more videos!

[@joeblowjohnny2297]

Hi Matt , AWESOME videos ! I was hoping you can make a 100 amp batter charger ? I didn't see anymore videos ? Thanks for reply Matt !

[@MattsAwesomeStuff]

Sorry for late reply. Yes, 100 amp battery charger is possible, but you would need a 1500 watt MOT. Also, it's only good for short term (jumping), not a walk away charger because the MOT would melt. To build a battery charger, plan on 11v output. You'll need a 100 amp FWB rectifier ($10-20) or 4 diodes to convert it to DC, and then some large capacitance to help smooth it (20v capacitors, electrolytic, at least a few thousand uF). The FWB will eat 1.4v because the path is through two diodes (each eat 0.7V), so you'll have around 9.6 volts after that, but AC's peak is 1.4x it's RMS voltage, and your battery will charge up to the peak, so, 9.6v * 1.4 = 13.4v. That's about right for a lead-acid "12v" battery. Car alternators are often set to 13.8v. To build a charger you can walk away from, you need to add almost double the turns on the primary. Shoot for the same target on the secondary. You're not going to get much for amps, maybe 20-30amps. Check it to see how hot it gets.

[@pauljordan3064]

Another great video with really clear and concise presentation, Thanks! (But I'd have to say that your skill in electronics and talent for teaching is equal in magnitude to your lack of carpentry skills lol)

[@MattsAwesomeStuff]

They are original. The laminations often have the holes if there is a jig that the helps assemble them nice and square into the transformer. Depends on the factory/process. Don't despair. Just use some epoxy, silicone or any of the other solutions I suggested. A couple wraps of tight duct tape even works fine, even though it impedes cooling and will eventually dry out and flake.

[@RaglansElectricBaboon]

Love it, thank you for this series. PS Did you expect to be entertaining folks in NZ 8 years after posting these videos!?

[@oddjobbobb]

This is a really informative series. I learned a lot about transformers generally and MOT in particular. A couple questions, although I understand I am a while behind. If I have a MOT from a 120 volt microwave oven, I can’t connect the MOT from that oven to 240 volts because it won’t have sufficient windings? 2. If I want to make a spot welder, making the secondary with one very heavy U-shaped turn is preferable to two or three less heavy turns? 3. On the secondary you turn, why do you want so much gap between the core and the outer loops of the secondary? You used a pencil width at each end, but the original secondary seems like it was very snug to the core? Is that because the original was machine made and could have closer tolerances? 4. The core of the MOT has very shape corners. Is the transformer performance diminished if, after fully dismantling the MOT the edges of the corners were softened a little bit? Thank you got this excellent YT series. Lots of help.

[@dav3fk]

Hey matt - I'm looking to make a 110v stick welder for low amperage stuff - there seem to be a lot of people who have a lot of tutorials on this sort of thing, but all of them either have glaring (even to me, an electrical idiot) safety/functionality issues, or they build something a lot bigger than what I want, or complicated in all the wrong ways, with no particular gain. I was thinking of a dimmer switch to control the output from the primary side, and hoping that I could simply have one transformer, (maybe, hopefully)with the welding cable wound directly as the secondary, such that I could have a welder in a box the size of a large MOT, with just a power cord, two leads, a knob, and a switch, capable of running 3/32ths electrodes. With the videos out there, I could absolutely figure out how to build a bog standard buzzbox, but I have one of those, I want something the size of a lunchbox that you can plug into a normal outlet and start welding with. I could live with multiple transformers, but would much rather have one - at this time I have the transformer (and capacitor - which I thought might be useful in helping to get an arc started, I could be misunderstanding things though) from a 1000w microwave, but could probably get one from a pretty big (industrial, or nearly so) one if needbe. The popular videos on microwave welders are exactly what I do NOT want: different 110v sockets powering a sprawling monstrosity of a fire/electrocution hazard - making a few passes is totally acceptable to me, having a shameful disaster of a welding "machine" is not. I know that this is intellectually lazy of me, and that I should be able to study up and answer my own question, but it seems like something you should be able to answer off the top of your head, with your handle on this stuff, and I'd rather not delve deeply into it, just to learn that I'm wasting my time and it's impossible.

[@MattsAwesomeStuff]

Thanks, that's very kind of you to say.

[@MattsAwesomeStuff]

Thank you for the kind words.

[@JoshBrownPhotography]

haha the sense of humor is very good

[@PatrykDarasz]

thanks, bro, its a very good tutorial.

[@petergdk]

This series was really well made, and very informative. I'm in the process of making something as simple as a hot wire foam cutter, and i need a 2x12v/24v transformer, so i am able to swich between those voltages. You video made it very clear that i can just make 2 secondary windings, and connect them in parallel or series via an on-0-on switch, depending on what current i need. I see a lot of people using hot wire foam cutters, just putting a cheap single pole incandecent leading edge dimmer in front of the primary, to limit the current, and thereby regululating the temperature of the hot wire. Won't that cause problems with saturation? (I'm not even sure i completely understand transformer saturation, even though i've tried to read up on it - so i might be wrong). Anyway - your videos are great, and i really hope we will see more videos from you in the future, since your kind of videos, with both humor and educational value, that can be used practically, are few and far between. I can tell that you take pride in producing high production value videos, by the quality of your work, but i would be happy to see you sacrifice a little production value, if i could just get to enjoy some more content from you :). Good luck

[@MattsAwesomeStuff]

Glad I could help. I have built a hot wire foam cutter before using a car battery charger (old style, just a transformer and diode). I threw a dimmer on it (primary side, as you correctly figured) and it worked fine. No saturation issues for me.

[@kerimil]

you're awesome - thx for this tutorial

[@nadingjeff]

Matt, Awesome Stuff, cool dude, I like it.

[@MattsAwesomeStuff]

I agree. That's why... I did exactly what you describe. Did you watch Part 1 like I said this was a continuation of?

[@MattsAwesomeStuff]

Connect one wire from each primary (left side of each) together and connect that to one side of a 220V cord. Then connect the other two to the other side of the cord. On the secondary side, if you want 18V output, connect lefts to lefts, rights to rights. If you want 36V, connect the left of one to the right of the other and then tape and hide that joint. Use the remaining two wires as your output. Either way, if you get near zero volts, flip ONE of the MOT's output wires (switch its left/right)

[@Donisgr]

Very nice tutorial, when the spot welder tutorial will be uploaded?

[@xhdbc]

Thanks a lot! Awesome videos

[@Donisgr]

Thanks for the quick reply. I'm not sure if it needs something more than just to replace the secondary coil of the MOT with a thicker one copper wire and thats all. I don't need it for some special job, i just find it a very interesting project and i have 3-4 not working microwave ovens and some 150kg of cooper wires for recycling so i thought to make something usefull with them. Anyway i'll be waiting for your next videos.

[@TaOO]

thanks man this helped alot!

[@aleke8328]

Love the turntable

[@MattsAwesomeStuff]

It's a computer fan :p

[@AlphaTroniks]

I'm planning to use 4 MOTs because each houses 8 turns so 8V x 4 MOTs =32/34 Volts approximately.

[@MattsAwesomeStuff]

Script's done, I have extra microwaves. Takes about 100 hours of work for audio/video/graphics/edit. Could be a month. You're subscribed so, you'll see it when it arrives. If you're impatient: A spot welder is a 1-turn secondary. Use scrap copper. You can do it for free using your old secondary but it's laborious to explain in text. I see you like chainmaille, is it for that or for sheet metal?

[@NoxuzBlog]

i mean srly the kinda humor you added to this is awesome

[@santoshmane3383]

Nice demo sir . Thanks. I want to use this 12 volts 40 amps mot power supply to my Hydrogen generater could i run it continue ? What sq.mm of wire have to use and how many turns have to wind ?

[@99frofro]

Attempting a stick welder build with MOTs. Right now using two one I rewrapped the primary the other came stock, got about 35v open circ. voltage on the secondaries...using 120v wall socket primaries wired in parallel, although considering doing separate socket for each. Lays a decent bead down but so far can't get it to weld 1/8" steel together

[@MattsAwesomeStuff]

35v is a bit high, maybe, it's stealing all your amps. 1/8" may be impossible. Good job even getting a bead. Go devour some 1/16" or 3/32", see if those work better? Primaries in parallel are tricky, unless perfectly matched. But seems you've got it to work regardless. I cover this in some followup videos I haven't finished, because I treat my fans poorly and I'm lazy. You're doing well.

[@99frofro]

Update: Was able to attach some light mild steel together but very crappy weld "attachments". Wouldn't call them beads. Lots of slag getting in the way. 6013 too little penetration I need some 1/16 6011 which is extremely hard to find. Gonna try and get the 3/32 6011 I have working. Keeps sticking.

[@MattsAwesomeStuff]

Alok - I'm not going to troubleshoot privately. If I'm going to say something, it'll be here where at least other people can learn from it. MOTs run ~1000 watts. You've got 4, so that's 4000 watts. Maybe more if you knocked out the shunts. Yeah, that'll blow a breaker. Nothing you can do. Primaries in series would cut down on losses, but also cut your power in half. Scariac is one way to go, but it's a bad way. A beefy light dimmer is cheaper and easier. I have a couple other ideas but they're not explained quickly. Also, those limit the power when you weld too fast, that is not your problem, your problem is that you cannot supply the amount of power you need to weld. 2.5mm might work, but I think you can find.. ~1.6mm sticks as the thinnest size. That will make a big difference. You can also wire your MOTs to separate plugs, and plug them into different circuits in your house on extension cords. Not just separate outlets, outlets each on a different breaker.

[@MattsAwesomeStuff]

You're wrong, they can. However, they get extremely hot when doing it, and cannot maintain that level of power for more than about a 5-10% duty cycle. A larger transformer would be able to maintain 100% duty cycle, but similarly, you could get a lot more power from that bigger one at a 5-10% duty cycle too.

[@lordzeppo]

very nice video! keep it up Th3BadWolf

[@stupid-handle]

By what you say on this last video, I guess it would be better to buy E and I plates to build a transformer to suit? Or are there some advantages in using an MOT core in terms of efficiency or power output (other than it's a block already made for us, in a smaller factor than a hand-made E/Icore could be for the same power, I guess)? Also, you showed in this series MOT's with their secondaries' wound around their primaries, but didn't gave them any specific mention? I guess these will perform much better at the cost of having to wind a brand new primary that covers the inner core?

[@MattsAwesomeStuff]

The only advantage of MOTs is that they're cheap. They suck otherwise. And yes, winding the other way just requires more wire and more work.

[@RNA0ROGER]

I might use this to make a pure signwave inverter.

[@MattsAwesomeStuff]

@tomatohodson : Everyone does, that's why I kept 'em. :) Trivia: Crappy thing happens if I speed up audio too fast (past about 8x) it ends up muting it to zero in compression. So, I actually had to manually manipulate the sound in an external editor to keep some of the effects. Worse, this didn't show up in preview, only the final renders, so I had to re-render every time to find out what it might sound like. Never found a fix for it, hours of playing around trying.

[@ThePlanetnewbs]

been doin shit like this for years. This vid is perfect for u toobers... I see many more subscribers in you future. good luck

[@AlphaTroniks]

I have a question... Do I need to wire the primaries of two transformers in series or parallel? I am planning to use 3 transformers if 2 fall insufficient for my MOT Welder. I'm confused on the wiring. My country runs on 230/240 Volts AC... Thanks in advance!

[@MattsAwesomeStuff]

4 diodes or a rectifier you need, any can handle the voltage, but they must be sized for proper max amps. Fairly big, Ratshack probably doesn't have any. The control board in the microwave might have small ones you could try and fry. Rectifiers are black with 4 leads and usually a corner cut. Also, you need capacitors to smooth voltage bumps. At least 20V (much extra won't help and will add cost), and hundreds/low thousands of uF. Hard on motor otherwise.

[@RobertoDeAlmeidaIsNotUnique]

I loved the video! Now I want to go and build a transformer for something. :)

[@KirkMcLoren]

well done tutorial

[@MattsAwesomeStuff]

@ebb0246 YES! Absolutely. I have a dozen+ tutorials planned. First is the spot welder, second will probably be the arc welder. Hint: The orange transformer I made in these tutorials? That's an arc welder. If you want to get right to it... Specs: ~24-36V, as many amps as possible. Add a fan or two. You'll get 10% duty cycle (1min weld, 9min cooldown). You'll need to use the smallest sticks (1/16"). A double-MOT is better. I wish I could make videos as fast as there's interest for them.

[@careful34]

Great videos! Thanks for making them! It seems your newest is about 2 years old at this point. Have you moved on to other things, or do you have another channel somewhere? Weird how sometimes a channel takes off, and sometimes it doesn't. Hope this one catches fire (in a good way)!

[@MattsAwesomeStuff]

+careful34 I'm still around, no other channel. I have so much content planned and half filmed, dozens of hours. I just suck at completing projects and my educational/volunteer efforts go elsewhere these days. I think my channel has caught fire, I mean, I've got like 4 videos and am coming up on a half million views. That's pretty nuts for a slacker :). I was very close to filming a new video yesterday, I have a new camera, so, hopefully soon. Thanks for the encouragement.

[@careful34]

They're very good vids! They deserve to take off! All about self promotion and all that. Hope to see more of them! Good Luck!

[@harukoyama9515]

Thank you so much for the direct answer. I ask EBay seller the same question. They have no clue. So basically I need to purchase multiple rating amp meter for a accurate reading. Or is there a devise that will measure all current of all size accurately?

[@MattsAwesomeStuff]

Many multi-meters will have a range, or even an auto-range function to measure many ranges. I don't like autorange just because it's slower, you have to wait for it to figure out what range it's supposed to be. Most multimeters max out at something like 0.5A. Then there is a separate connection for up to 10A. Above that, you usually need a specialized meter with a calibrated shunt. Why do you need to measure current so precisely at such high currents?

[@greenalyd]

cool!!! I want to make a stick welder with two of those MOTs but its posible to make a welder with amp range? thanks!

[@harukoyama9515]

Again thank you very much to pass on these important power conversion knowledge. I had to read it few times to absorb it. So basically for my 18 voltDC tool need: 1. Rewind transformer with gage 8 house wire to convert 110Vac to 17Vdc likely 14 turns. This will provide max 65 amp for power tool draw. But I can check voltage with my 10amp multi meter. before load. Correct? Because only when tool is running. Will withdraw more then 10 amp. 2. Need to find (4) 100amp p/n type diode from alternator. How can I check to see if diode is still in good working order? 3. DCDC converter. This part just fine tunning DC input like how many turn on Transformer does right? An alternative to this DC DC converter. I could connect end of 17Vac output to a longer bare alum wire. Just by adjusting the length clip end on this bare alum wire. I could adjust the Voltage correct? By doing so, per prior message, the volt and amp will adjust accordingly up and down. Not a smart wiring. The closer clip is to transformer end the closer to 17Vac... Is this correct thinking? 4. Is there an alternative way then purchase this giant expensive capacitor? Can a bucket of 5 gal water mix with Epsom salt provide a same function? The more Epsom salt the more conductive the more volt it can store. Like ancient egypt battery. Or Can a used car battery provide smooth out sin wave function?

[@MattsAwesomeStuff]

1 - You want to use the largest wire that you can just barely fit all 14 turns into the space in the transformer. That will depend on how skilled you are, and how stiff your wire is. Yes you can check voltage with meter before load. To test amps you do not test the same way as volts. To test amps you have to insert the meter into the circuit, (you have to break it open and add it like a switch). You do not need a separate transformer for every tool, you could create a generic power supply that you can plug into any tool that has the same voltage. I usually use the dead case of the old battery and use nuts and bolts as terminals to screw the wires on. 2 - Diodes are not likely to be broken. Usually alternators break because of bearings or wires. A diode should block electricity in one direction, but allow it in the other direction. It is like a one-way valve for electricity. You can use a car battery and a car light blub. Connect the negative to the bulb, connect the positive to one side of the diode, then connect the other side of the diode to the bulb. It should light up in one direction, but if you connect the diode backwards, not light up anymore. You might not find 6 individual diodes, you might find a big black half-circle with 6 connections on it and have to figure out with trial-and-error which wires are for what. It probably does not need to be tested. You can also just buy a FWB on Ebay. 3 - A DC-DC converter is usually used to do more complicated work, you are only slightly using it to make steady voltage. For tool use this does not matter at all and can skip it. Adding a giant power resistor will limit how much current will flow, but not control voltage directly. This is a bad method. Also, aluminum will not work, aluminum and copper have too low of resistance, you would need hundreds of feet of wire. Use stainless wire or wire from anything that gets hot (toaster element, stove element, hair dryer, clothes dryer, space heater). But, don't do this, there is no advantage. 4 - You can connect many spare capacitors together like LEGO. In parallel, you just add their uFs. If you have a 200uF, 500uF, and 1300uF in parallel, you have 2000uF total. In series you double their voltage, but their uF is cut in half. That gets complicated, so I would just pick 50V-75v capacitors (look like small cans) and connect them up in parallel. Old power supplies and stereos especially will have big capacitors you can use, near the power cord inside. The biggest thing that looks like a can. No, do not make your own capacitor, waste of time. No, a car battery will not smooth out anything, and you cannot charge a car battery to 17v, it will explode. A car battery on its own could run the tools directly, but, probably only at 1/3 the power since they are rated for 18v and you are only giving them 12v. They would spin slow and almost stop when you go to use them. But, they would work. Lithium tools might not let you, if you use the control electronics, but old NiCad battery tools would work just fine. See this unlisted video I made: kzbin.info/www/bejne/a3ucgYWtl9uUjZo

[@konstantinNeo]

@MattsAwesomeStuff You have put up some great info for projects and if there is any hazard that may cause harm it should be put in as well. You do this automatically about electricity and by now almost everyone knows about it, but the beryllium part is not so obvious. If someone wants to go ahead and smash the magnetron (for whatever reason or by whatever means) it could become a very ugly experience, the implications and reasons should be stated. Your video is great, I love it.

[@zubeirmohammad8262]

hey matt, i want to make a stick welder with the 'E' cores and i want to have different amperage from the secondary winding, so could help or suggest me some ideas on how to make it Thanks

[@bluefire87HN]

when you create a new video?! you are great!!!!

[@tomatohodson]

@MattsAwesomeStuff I wonder if that was the compression algorithm stripping out higher frequencies or something else. As an aside: what type of currents does your one turn secondary spot welder carry, I wonder if a cast aluminum loop would make a good secondary.

[@zeelhazard]

Matt you REALLY do awesome stuff. Although I do wonder how to reuse the wiring from a secondary coil to make a new secondary coil with fewer turns. (Basically i just wonder how to clean all the enamelled insulation, if even necessary) Anyway, your vids rock, and since I've studied a fair bit of physics and maths I appreciate the fact that you also try to teach others how to use it for something good.

[@MattsAwesomeStuff]

Thanks for the kind words. You sound smart so I'll give you the abridged version. You're making a cable: 1 - Uncoil the whole secondary into a separate loose coil, a drill helps. It goes easier once the outside few layers are done. It's 2000' of wire, it takes a while. 2 - Place two pegs either the distance apart you want the end cable to be, or, half the distance. 3 - Walk the loose coil around the two pegs. It's 2000', it will take you a while. 4 - Cut the cable off at one peg. Either bundle it all up, or cut it in half, depending on which length you were targeting. 5 - Flay out the last few inches of each end and clean them somehow. Abrade them with a steel brush, burn off the enamel then vinegar scrub them clean, something. 6 - Using some type of clamp or something, clamp all the loose ends together in a few places to make sure the strands are all connected in parallel. 7 - Wrap the cable with kapton tape. 8 - You're done. Wrap it on the core. Because you're re-using the same amount of copper, it's always self-scaling. You'll end up with a coil that is about as thick as the max you could have fit into the core with the number of turns you needed.

[@zeelhazard]

MattsAwesomeStuff Can't thank you enough for those instructions! I've always been amazed by the kind of youtube channels that help people (like yours) without getting much in return in the shape of money or fame. Although I have a hard time wrapping my head around how it could more time efficient to answer all the comments rather than making a video containing all the answers to the most common questions :P

[@MattsAwesomeStuff]

Oh, it's not efficient. I didn't mean to take a 3-year break from filming, but... answering questions is a few minutes at a time. Making new videos is a big timesink that I need to be in the right headspace and workspace for.

[@MattsAwesomeStuff]

I say in the video. About one foot per wire, add a couple feet for hookup. Or, measure.

[@konstantinNeo]

A bit about magnetron safety handling (copypaste from wiki): "Some magnetrons have beryllium oxide (beryllia) ceramic insulators, which are dangerous if crushed and inhaled, or otherwise ingested. Single or chronic exposure can lead to berylliosis, an incurable lung condition. In addition, beryllia is listed as a confirmed human carcinogen by the IARC; therefore, broken ceramic insulators or magnetrons should not be directly handled."

[@pietzeekoe]

So are you still ganna make a spot welder tutorial?

[@Ghandisgarage]

I LEARNED SOO FREAKIN MUCH!!! when i get my time machine done, 5 minutes after you completed that video i'll show up and give you 10 million dollars.... you wouldnt happen to know how to pressurize light would ya? im serious.

[@neonboy22]

There are many kinds of coating on wire. Which one is best for high voltage insulation ?

[@tabhorian]

I'm making a stick welder. One guy makes a "Scaryac" to modulate the power going into the primary. That really does scare me. I have heard that wrapping a coil around a core and then moving the core in and out of the coil will vary the power. How does that work, and how do you do it?

[@MattsAwesomeStuff]

Yes, very easy. A stick welder is ~20-30v or so. You don't really need much for current range, since two MOTs is about the bottom edge of what you can pull off for stick welding. I show both how to make a stick welder, and how to control the current, in stick welding and other projects... which are only half-filmed. So, answers are coming sometime, just not done yet. Sorry :P

[@Tankerbuzz]

If i wanted to max output amps what turn ratio would you suggest since you cannot just put 1 in the secondary? Also could you explain the reason for this briefly. I have finished high school level physics so do know a fair amount already :)

[@harukoyama9515]

1. Trying to estimate how much watt a power tool is design for. So I can kind know what FWB amperage I need. Bigger the motor , bigger watt, smaller motor, less watt. The different between full wave and half wave is full is using top and bottom sin wave. While half only use one side which is also half the amp. Is this correct? The rectifier block specification sheet does not say it is full wave. Is this mean it is half wave usually? 2. After I removed compacitor, how do I know it is still good? Visually the top of cylinder cross is not buldging or black shown overheat once before? After removed it from circuit board. How do I know which side is positive and which side is negative? Or Does not matter?

[@harukoyama9515]

High current is what melting metal to red hot while high volts just make metal splitter in the welding process. I see. Thank you. Is there a different between AC and DC Compacitor? Is it all just bunch coil wrap inside the cylinder. Can Microwave Compacitor 200u uf used to store 36Vdc current for example???

[@MattsAwesomeStuff]

Capacitors are not coils, very different. Capacitors are not wire, they are two materials with chemical between them. Some capacitors are for AC or DC, some only for DC. Capacitors store energy. They have max voltage. How much charge they store is "uF". You want a capacitor that is higher than the max voltage they will ever see, but not too much more or you are wasting money. 2x voltage is a good ballpark. If 36v, then get at least 50v max rated capacitors. Or 75v. But not 100v, no reason. Same volume of capacitor at lower voltage will have higher "uF" number, which is more energy stored. Microwave capacitor is 2000-4000v AC but only 1uF. Useless, no energy. Same size, a 50v capacitor would be 20,000 uF. Microwave capacitor is only useful for microwaves, no other device needs voltage so high. Check computer, stereo, and TV power supplies for good large Capacitors.