One main reason I keep enjoying your projects is that you do a great job explaining step by step process involved even in the most basic things. Great job sir.
Hi thanks for a very informative video. I do however do not agree with your indication of the magnetic path. The magnetic fields will split at the centre pole and flow the the other two faces generated by the cut you made. If you lay the magnet on its side on a piece of paper and energise it lightly and then sprinkle iron filings on the paper the filings will align with the field and you will be able to see where the magnetic path is.But none the less I think it was a cool video and was presented in a very logical manner. Thanks very much Louis
We just had roofers replace the shingles on our roof and I was thinking of how I could pick up all the nails that where left behind. Something like this with a lite weight battery on wheels to go over the ground and rip all the nails and metal from the soil would be perfect.
Not sure if someone has already pointed out this minor detail, but I will go ahead and do so: when he drew the magnetic field lines for the transformer after being cut in half, the field lines should have actually gone from the middle section out towards the two open ends of the transformer at the bottom, not towards the closed end of the transformer on top. The vast majority of the flux goes in and out of the open ends, not the sides or top. You will notice this if you try to stick some iron on the top of the transformer- it will not stick nearly as well as on the open ends at the bottom. Very cool video though, and nice way of illustrating things!
Energy flows in the path of least resistance. Therefore the flux will take the straightest path from the copper the iron core because the air presents higher resistance to the flow or current produced by the power supply. Energies natural state is to 0.
@@buckaroundandfindout Yes, the magnetic field will avoid going through the air any time it can, but if you put a gap in the path of the magnetic flux like in this case here, it will go through the air. The two ends have one pole, and the center has the other. The magnetic field is trying to complete the circuit between those two poles in the most efficient way possible, therefore it will come off the ends like I described. Any other path would be longer than that.
@@HeyChickens constructive Central pedal divergence is what you are referring to. Yes some flux lines will flow through the air because there's no room for them in the path of least resistance. Especially in the case of an electromagnet where the force is being pushed into the dielectric field thereby forcing the internal forces to become external. Gaussian flux is introduced to a piece of steel in which it is changed fundamentally on the molecular scale therefore allowing a bypass of the flux fields in what is known as counter space. Where you see the flux in a feral cell is usually the path of least resistance ergo where the force is not located in the flux line. The force is in the space in between the flex lines, that is where you will locate the bulk of the energy that is being displaced via the lack of pathway in least resistance.
Furthermore magnetic attraction is a little bit of a misnomer as far as the words and language describe the actions. It would be more accurate to say that two pieces of metal rushed to a null point that is a convergence of flux lines in relation to the spin of electrons due to the polarization of rare earth metals. Ergo Force equal to attraction is acceleration to a null point.
Very impressed👍When testing heavy loads, make sure to insert safety link in both directions (use slightly loose rope), if the magnet fail at 300kg or more, the steel block will hit the car and the magnet can hit you with a great force, be careful!
Yes! Newton's first law of motion comes to mind, "Every action has an equal and opposite reaction". Yo certainly don't want that magnet flying off and hitting your shin, that would break both tib and fib easily
Great and useful project. I'm a woodworker with a good quality cabinet saw. I use two electro magnets in a wooden feather board to guide my work through the saw instead of using my hand (for obvious reasons), I can position the feather board anywhere on the cast iron table to fit the work I am cutting. I wished I had seen your vid before I purchased the magnets from Aliexpress. Going to build your drill press vice next.
Very informative video and it gave me great info on which type of voltage/current to use. Here's a project that I'm starting to work on. I go prospecting for gold out here in Arizona and we have a lot of " black sand " in our good paydirt. I'm taking a 4" pvc pipe and going to tape/strap 2 of these on either side to pour the dirt through so the magnetic field will "stick" the magnatite ( black sand ) to the sides and let to paydirt fall through for further processing. Challenge is to build one of these and post a video. Thanks again and I'll post pics when I'm done.
Put different sized nails into different types of soft and hard woods at different depths and see if you can devise a practical electromagnetic nail puller.
Nails have so little surface area for the magnet to lock onto, it would be virtually impossible to devise an electromagnetic field (out of a microwave transformer anyways) capable of pulling a nail out of wood, especially hard wood...
I’ve seen loads of videos on microwave transformers converted to spot welding transformers, but this is the first time I’ve seen a conversion into an electromagnet. Nice work! 👍 I’ll give it a try myself.
Yup, a storm's power surge took out my microzappr, I knew there was a good size transformer in it and cut two groves with an angle grinder. Having an old truck battery with external cell connectors, I can use at 6 or 8 volts and not overheat the primary coil.
@@headbanger1428 a microzapper is just another term I use for a microwave oven, that's all, Maybe I should have called it a micro-doo-hickey, a micro thing-a-ma-jig.
Good to see that I am not the only one obsessed with magnets! I couldn't help myself - I made a video on my channel several years ago. You have given me a few more ideas...... I have several microwave transformers that might be taking on a little transformation themselves 😁 Next term I will be teaching night classes on automotive electrical subjects. I drag around a rolling trolley with heaps of wire and you guessed it.....lots of permanent magnets as well as electromagnets to show students how solenoids, motors, relays and other tricky electrical components work. I usually use a rotor out of an alternator as an electromagnet to show magnetic strength holding a solid shaft of steel, but your idea might be a good alternative (excuse the pun) option! Keep up the good work! 👍 G'day from 'Across The Ditch' MiracleMAX
Keep reducing the power supply to the magnet ( volts and amps equally ) to see at what point it fails at 300 kg's, then find your wattage from that and divide it by 300 kg's to see your watt strength in Kk's lifting power. Great video, well made and informative, would never have guessed that a low resistance in the system would make such a difference.
Awesome video I enjoyed it… hopefully everything is cool down there in New Zealand looks like you guys are on lockdown over one single case! No deaths! Better days ahead ❤️
wow, i had not expected that strength with only a bench power supply. I was thinking about making a big electromagnet from scratch but when you can just grind away the weld on an MOT to have a super good one at hand, that'll serve me a lot of work.
Wow, very impressive cuzzy bro! Just one bit of feedback and maybe someone else has already pointed this out, don't have enough time to read through all the comments. That is in your explanation of the magnetic field path in the cut core, you've got it going from the center limb to the back of the core when in reality it is the same path as in the uncut transformer, via the left and right limbs of the core. You can confirm this by checking the magnetic strength at the back of the core and you will see that it is just as weak or very close to that around the uncut core. 300kg plus, holly sh....t! Keep 'em coming, great video and very enlightening. Cheers and stay well from across the pond.
A very good combination of theory and application, well done! One thing though: with a cut up transformer, the vast majority of the magnetic field lines go from the center bar to the side poles, not around the transformer (9:32). That's what causes the field loops to be closed when an metal object goes across.
That's a surprising amount of holding strength for such a small magnet. Maybe it could be used with cart type frame for a rolling gantry to move things around.
I've watched two videos on magnetic vices. One created a "magnetic table" that holds the work with the vice mechanically attached to the table. The other used the magnet to hold a traditional type vice to the table. Both have advantages. If you want to get really creative you could try removing the other side of the core as well and see if the drill press table would work as one side of the core making a magnetically held magnetic table. 😎
Great video, excellent descriptions! I'm wanting to build a trommel with an electromagnet Incorporated at some point to remove nails from wood ash. Thank you for posting!!!
Excellent demonstration of exactly the kind of info on electro-magnets that I was looking for. Thank You! I will be watching if you decide to utilize AC power in demo and it will be interesting to see the pro's and con's of DC vs AC with powerful electro=magnets.
very cool. so small yet so powerful. I made an electromagnet using a 65-pound steel bar and about two hundred feet of insulated copper wire. then hooked it up to a 12-volt deep cycle battery. it was strong, but not as strong as that little one you made. And it got hot quick. Thanks for the perspective. Ill change my design. ; )
You could make an electromagnetic door lock. Also, the reason I am studying magnetics is to make a large magnetic lift for scrap metal. I think you very much for the ideas I have taken from your videos. Great job.
I’m looking at building a system for our Jib crane at work to act on a switch to act as a brake system to hold the trolley in place (to a point) and possibly the swing
E-magnets are better for reaping/tearing uses than for lateral/sheering. Just think of those permanent magnet pickup clamps; when you turn them off you basically rotating the load to short the poles...
@@Graeme_Lastname I like good answers !!!! Thanks for explaining me, however ....could you please say more about 'basic principles'? Thanks a lot in advance.
@@isabellemarquez4806 Basic principles give you, among other things, the direction of the magnetic field when the direction of electron flow is known. Way to much info for a comment post. B well m8. :)
Great video man! You clearly put a lot of effort in it, and it shows. It would be a great electronic lock for your workshop. Not at max current, that would be too harsh for the winding. Or if you make it waterproof, it could be a great magnet-fishing device. Power it up with a car battery. And I sure can use a scaled-down version to get the thousands of tiny screws and bolts out of my long fibre carpet.
If cutting 2 slots and leaving it full size better than cutting it down as all clips shown? More iron larger surface area? Slots cut also would be nice flat and more iron to stick to.
What was the temperature of the winding after a few minutes? I would like to know the result of reducing the current to see when the 300kg is released.
Yup. Third that. What was temp° and could you please do a reduction in current + a fixed weight # so a ballpark value can be determined! :) thanks lots. Great channel and good on you!
Very usefull video. Thank you. Please try to compile a temperature curve e.g. for 30 minutes of metal machining. Somebody in other video checked the different voltage for input - 3V, 5V, 15V etc. Suppose max weight of metal machined piece cca 10kgs. What a appropriate Voltage by relevant temperture? What about a dBA or vibrations during work?
Thanks ,guy. Thats a cool idea about an electric vice block,like a workbench that holds things still while you're working. You should patent it(fast)!!😉
Something of note that could be relevant. Magnetic field is proportional to amperage times number of turns (plus or minus difference of losses) A 200 turns at 4A electromagnet will have almost the same strength as a 400 turns 2A one. Only case by case differences will make one or the other slightly stronger. Well, there are other factors to take in consideration when choosing one over the other, such as power loss into heat, thermal properties,... but that is more relevant when winding an electromagnet from scratch. The point here is to use easily available material and minimum complexity of modification. Which microwave transformers fit perfectly, plentiful, cheap and easy to power.
If you don't mind a question: how can i determine the max or correct amperage to run thorough a primary winding? Can i use the labeled values on the transformer? I also have a question about height of the legs on the "E" frame the windings are in. Is there a sweet spot in relation to the ark of the magnetic field for an increased gauss value or just closer is better? Lastly since the magnetic field is the same at each pole can I use plates on the side and leave both poles ooen to have the ability to hold items on top as well as hold the device down to a metal surface as needed for a drill press? Thanks in advance for any illumination you might care to offer.
In other words a transformer core contains all the field, as long as the core isn't saturated. Thus external iron doesnt interact with the magnetic fields inside the core. But where the field exits the transformer core, they can interact with external ferus metal.
The field lines are are in a close circuit. The horse shoe magnets would be having pole pieces when stored for long time. The torroid core design assures self shielding meaning any other torroid core transformer can be placed just beyond half the diameter distance of the bigger one. In the case of a solenoid winding to minimize/ avoid interaction the coils would be placed perpendicular to each other and in the case of a third coil, it would be placed in the vertical plane. You can observe this in the radio circuits.
@@subramanianr7206 if one rewatches the video 5:14 , the original core before being modified was expelling some magnetic fields. That's indicates over saturation that inturn indicats one should run fewer amps due to the fact that the rate of increase in the magnetic field drops due to drop in a decrease in permibility. en.m.wikipedia.org/wiki/File:Permeability_of_ferromagnet_by_Zureks.svg But, on rexamination of transformer design, i might be wrong on the saturation current after the core was modified. Transformer design sometimes introduce an air gap to increase the saturation current level. Cuting the core in half introduces a large air gap in the magnetic circuit. Presumptively, that will also increase the saturation current level, maybe well beyond 4 amps. The large air gap now allows for using the core as an electronagnet. But when a piece of metal closes the air gap, the saturating current level will drop. Take away is that there are more things to consider what current one wants to run depending on the core and how one will use it.
good boy.....same as i use...angle grinder/chop off saw (homemade from furnace motor, and microswitches from microwave).....to re-create MOTs for chargers, welders, etc. made an 18 volt dc supply for cordless tools, converted to corded tools, ...mots rewound for 19 volts dc with capacitors and bridge rectifier.....all work wonderfull....good for you...
Your video is great, you don’t just explain things really well but you jump in with everyday practical experiments we could all do. That is really powerful and to think it came from an old microwave transformer too, I will use this on my own project, thanks
What if you made like 10 of these and attached them to the loader of a tractor? Curious as to how well it could find old nails and screws for construction site clean up.
solid metal will be stronger the laments are there for AC current to eliminate eddy current. the more turns the stronger the magnet will be, to keep the voltage down you can rap the wire by double or more. because there is no magnetic field fluctuations you don't have to worry about eddy currents or induced back voltage so your wattage will remain low. great video.
You can double the range of your measuring instrument by using a simple tool called a 'snatch block' which consists of a single pulley, You will have to move the cable running thru the snatch block twice as far as you would be moving the load, but you would only be using half as much force to move it. Just measure that force and multiply by 2 to double the measurement range of your instrument.
Excellent video particularly on ease of selection of the transformer. A very cheap mag drill is in my mind I always wanted, and, what I really want to do is a cheap method to have a kill switch on my digger I need to be activated by trips for safety where the "real thing" dam near costs more than the machine. (the magnet will hold the fuel shut off open and another can similarly lock my hydraulics simultaneously on the same electric circuit). Thinking that much power would also work as a lock on the slew control (it's the real one that kills people tripping or catching clothing) in a circuit where if it's not locked the fuel and hydraulic one power off). Been trying to find a way to do this for ages.
great video. I would like to know what would be the formula to calculate the force applied by the current and how it would change? Does anyone has any clue ?
The commercial magnetic bending brakes are using 220 volt electro magnets generating 6 tons force spread out over 48 inches to secure material. Would like to see what you could come up with!
I have a transformer from an old welder , It is huge compared to these ones in video it has wires that are bery big on the winding , would that be a good one to use ?
Thank you for this informative video ! I surly could use the electromagnet that you demonstrated, to pull dents out in autobody applications ! The setup that you have would help me GREATLY in repairing my truck !
Different steels have different magnetic saturation points, where the magnetic forces pulling towards the iron core is drastically reduced per amp going through the windings. If this point was reached at say 80% current draw of what he is drawing in this video, and then half the current to take a measurement. you only had a 20% drop in magnetic force but half the current draw, thus giving a false measurement. (These numbers are straight out of my ass, and only to prove a point)
So what if you replace the secondary coil with another primary coil in an MOT? You would eliminate having to chop off half of the block, but would it double the power? And would you connect the two coils in series or parallel? And would you reverse polarity on one of the coils? Would it matter in AC, DC? Sorry about all the questions. 😂
Well I know you can't reverse polarity on one of the the coils, you def want the same, but that a good Idea if you have 2 of the same broken microwaves. Lol. Not sure if parallel or series would create a stronger magnetic pull. Im thhinkin series cause more amps
I had the same question couple weeks ago... after cutting a mot into the E shape I placed another coil on top of the primary coil.. connected 2nd coil to the leads of primary flipped the switch and POW!! i thought fk it blew up .. then simultaneously heard a loud thud and something hit the top of my right shoulder... the 2nd coil I placed on the primary coil shot straight up off the mot transformer.. broke the wires off itself as it headed for the ceiling.... I was dumbfounded to say the least ..
@@codyramos3200 I knew there would be polarity issues, but didnt think about the power involved if connected north to north. Yeah, i guess it would do something like that. Did you try reversing the wires?
@@siggyretburns7523 uh I can't say if I did ... I soldered 1 end of the 2nd coil to another coil to make 1 large coil to work as a secondary coil for a step up transformer... it takes a ridiculous amount of wire to go from 110v to 550v ..
What is the purpose of the stacked piece??? I just bought a surface grinder that is missing the magnetic chuck. I must build a chuck and can't afford to buy one. If I simply weld up steel solid and roll the wire , will it have the same holding strength??? I have made these microwave mags before for material handling. They're great for that.
No. But it doesn't have to be complicated. I reckon a computer power supply would be a good candidate. Limiting the amps is the most complicated part of this project.
You can limit the current, from an AC source, by using use an AC capacitor, on the hot AC lead of primary, and using the Capacitor Reactance Formula to calculate in Ohms.
@@OtherDalfite Wasn't what I was saying. I assumed you would use a rectifier, but, before it gets to the rectifier, you can limit the current using a capacitor on the hot AC lead using capacitor reactance formula. Example: 108 UF capacitor limits the current due to Capacitor Reactance Capacitor Reactance = 1 / (2 * PI * Frequency * UF / 1000000) EX: 1 / (2 * 3.14 * 60 * 108/1000000) = 24.57 Ohms 120 VAC / 24.57 OHMS = 4.88 Amps
great explanation. Wish I had you when doing my apprenticeship. Got there in the end haha. Looks like you could have used an electromagnet drill vice at 6:19... What about an electromagnetic drill press bed so you don't have to use a vice at all. Still looking for something similar for aluminium too...still looking
very impressed! I was getting worried that we were close to find out what the weakest link of this setup was rather than the electromagnet strength itself. it might have snapped and smashed the car or fly in the air at random. great demonstration!
Quick question, I have heard there is a need for a diode in the power supply circuit due to induction from the field collapse ( I believe) . Can you tell me what the item is that I have found on all the microwave I have gathered, it is a black cylinder thing connected to the capacitor then to ground. Thanks
Awesome advice and well presented! I learned a lot. I do have one piece of advice. Next time don't heat the laminates in the core. They do have lacquer on them for a reason. Laminations perform better in a transformer core than solid iron or molded ferrite powder. It's important for the laminates to be separated from one another with the lacquer. If they touch one another conductively it reduces the efficiency of the core. Next Time start with a new core that will not be damaged by taking it apart or welding all the laminations together into a solid conductive core. In the least don't weld the laminates together. Perhaps put it into a vice while applying some two part resinous bonding glue.
@@richardsellars8598 I used the term lacquer but I dont know what material engineers use to isolate the different laminations. I only know that it's a proven fact that isolated laminations create the least resistant transformation. You'd have to ask an engineer how they manage to retain isolation because i dont know.
What is the simplest way to make a small magnetic table so that i can make a small surface grinder about the size of an a4 piece of paper. My financial resources are very limited since i have spent most of 20 years in bed. Most of my metal and wood is what i find near the local garbage dump on each block close to home. I really do not understand electricity though i did completely rewire my house in new york 40 years ago. Thank you for your time and help.
One main reason I keep enjoying your projects is that you do a great job explaining step by step process involved even in the most basic things. Great job sir.
Hi thanks for a very informative video. I do however do not agree with your indication of the magnetic path. The magnetic fields will split at the centre pole and flow the the other two faces generated by the cut you made. If you lay the magnet on its side on a piece of paper and energise it lightly and then sprinkle iron filings on the paper the filings will align with the field and you will be able to see where the magnetic path is.But none the less I think it was a cool video and was presented in a very logical manner. Thanks very much
Louis
Correct,, that's why I enjoyed that project.
Good job.
Gardening with electric and magnetic?
Thanks your information ❤
Enjoyable video, I wish my Electrical Engineering tutor at college 60 years ago had, your interesting approach about magnetic flux.
Something about this dude just makes him enjoyable to listen to and learn from.
Grinding, drilling, clamping, mill work, dent pulling, project or heavy material transfer, lock and that is just off the top of my head. Great video
Yup , a magnetic chuck.
We just had roofers replace the shingles on our roof and I was thinking of how I could pick up all the nails that where left behind. Something like this with a lite weight battery on wheels to go over the ground and rip all the nails and metal from the soil would be perfect.
I will use it to load heavy pieces of steel Into my lathe and mill with my jib crane. Awesome video with how to and verification! New subscriber!!
Not sure if someone has already pointed out this minor detail, but I will go ahead and do so: when he drew the magnetic field lines for the transformer after being cut in half, the field lines should have actually gone from the middle section out towards the two open ends of the transformer at the bottom, not towards the closed end of the transformer on top. The vast majority of the flux goes in and out of the open ends, not the sides or top. You will notice this if you try to stick some iron on the top of the transformer- it will not stick nearly as well as on the open ends at the bottom. Very cool video though, and nice way of illustrating things!
Magnet in middle> magnet on-under
Energy flows in the path of least resistance. Therefore the flux will take the straightest path from the copper the iron core because the air presents higher resistance to the flow or current produced by the power supply. Energies natural state is to 0.
@@buckaroundandfindout Yes, the magnetic field will avoid going through the air any time it can, but if you put a gap in the path of the magnetic flux like in this case here, it will go through the air. The two ends have one pole, and the center has the other. The magnetic field is trying to complete the circuit between those two poles in the most efficient way possible, therefore it will come off the ends like I described. Any other path would be longer than that.
@@HeyChickens constructive Central pedal divergence is what you are referring to. Yes some flux lines will flow through the air because there's no room for them in the path of least resistance. Especially in the case of an electromagnet where the force is being pushed into the dielectric field thereby forcing the internal forces to become external. Gaussian flux is introduced to a piece of steel in which it is changed fundamentally on the molecular scale therefore allowing a bypass of the flux fields in what is known as counter space. Where you see the flux in a feral cell is usually the path of least resistance ergo where the force is not located in the flux line. The force is in the space in between the flex lines, that is where you will locate the bulk of the energy that is being displaced via the lack of pathway in least resistance.
Furthermore magnetic attraction is a little bit of a misnomer as far as the words and language describe the actions. It would be more accurate to say that two pieces of metal rushed to a null point that is a convergence of flux lines in relation to the spin of electrons due to the polarization of rare earth metals. Ergo Force equal to attraction is acceleration to a null point.
Very impressed👍When testing heavy loads, make sure to insert safety link in both directions (use slightly loose rope), if the magnet fail at 300kg or more, the steel block will hit the car and the magnet can hit you with a great force, be careful!
Yes! Newton's first law of motion comes to mind, "Every action has an equal and opposite reaction". Yo certainly don't want that magnet flying off and hitting your shin, that would break both tib and fib easily
Great and useful project. I'm a woodworker with a good quality cabinet saw. I use two electro magnets in a wooden feather board to guide my work through the saw instead of using my hand (for obvious reasons), I can position the feather board anywhere on the cast iron table to fit the work I am cutting. I wished I had seen your vid before I purchased the magnets from Aliexpress. Going to build your drill press vice next.
Everyone else on the planet would've drawn the magnet on the whiteboard with North on top. Not a Kiwi!.. Great vid, long time sub. Keep 'em coming!
hmm.....like this is as if a great suggestion 😅
@@mvnar What?
Very informative video and it gave me great info on which type of voltage/current to use. Here's a project that I'm starting to work on. I go prospecting for gold out here in Arizona and we have a lot of " black sand " in our good paydirt. I'm taking a 4" pvc pipe and going to tape/strap 2 of these on either side to pour the dirt through so the magnetic field will "stick" the magnatite ( black sand ) to the sides and let to paydirt fall through for further processing. Challenge is to build one of these and post a video. Thanks again and I'll post pics when I'm done.
Good luck with that I'd love to see that project working !
Love the way you explain what your doing !
Put different sized nails into different types of soft and hard woods at different depths and see if you can devise a practical electromagnetic nail puller.
yooooooooooooooooooooooooo
This
Nails have so little surface area for the magnet to lock onto, it would be virtually impossible to devise an electromagnetic field (out of a microwave transformer anyways) capable of pulling a nail out of wood, especially hard wood...
I’ve seen loads of videos on microwave transformers converted to spot welding transformers, but this is the first time I’ve seen a conversion into an electromagnet. Nice work! 👍 I’ll give it a try myself.
Yup, a storm's power surge took out my microzappr, I knew there was a good size transformer in it and cut two groves with an angle grinder. Having an old truck battery
with external cell connectors, I can use at 6 or 8 volts and not overheat the primary coil.
@@raymondgarafano8604 I could not find microzappr online. What is that?
@@headbanger1428 a microzapper is just another term I use for a microwave oven,
that's all, Maybe I should have called it a micro-doo-hickey, a micro thing-a-ma-jig.
There have been dozens of copies all the same for years.
Pathetic.
@@โนรีคอกเบิร์น Replies little man to a comment of 3y ago when there wasn’t.
Good to see that I am not the only one obsessed with magnets!
I couldn't help myself - I made a video on my channel several years ago. You have given me a few more ideas......
I have several microwave transformers that might be taking on a little transformation themselves 😁
Next term I will be teaching night classes on automotive electrical subjects. I drag around a rolling trolley with heaps of wire and you guessed it.....lots of permanent magnets as well as electromagnets to show students how solenoids, motors, relays and other tricky electrical components work. I usually use a rotor out of an alternator as an electromagnet to show magnetic strength holding a solid shaft of steel, but your idea might be a good alternative (excuse the pun) option!
Keep up the good work! 👍
G'day from 'Across The Ditch'
MiracleMAX
Really...you do have very professional welding skill. Thank GOD ....yes you do have! 😇
Keep reducing the power supply to the magnet ( volts and amps equally ) to see at what point it fails at 300 kg's, then find your wattage from that and divide it by 300 kg's to see your watt strength in Kk's lifting power. Great video, well made and informative, would never have guessed that a low resistance in the system would make such a difference.
Magnifique Monsieur. Merci pour la vidéo.
Awesome video I enjoyed it… hopefully everything is cool down there in New Zealand looks like you guys are on lockdown over one single case! No deaths! Better days ahead ❤️
Best explanation on TH-cam! Love the Brit speak. Bob's your uncle!
Dude your channel is terrific and I had to subscribe, and that would be perfect for a surface grinder application.
wow, i had not expected that strength with only a bench power supply. I was thinking about making a big electromagnet from scratch but when you can just grind away the weld on an MOT to have a super good one at hand, that'll serve me a lot of work.
Wow, very impressive cuzzy bro!
Just one bit of feedback and maybe someone else has already pointed this out, don't have enough time to read through all the comments.
That is in your explanation of the magnetic field path in the cut core, you've got it going from the center limb to the back of the core when in reality it is the same path as in the uncut transformer, via the left and right limbs of the core. You can confirm this by checking the magnetic strength at the back of the core and you will see that it is just as weak or very close to that around the uncut core. 300kg plus, holly sh....t!
Keep 'em coming, great video and very enlightening.
Cheers and stay well from across the pond.
This video must have million subscribers already... it is very informative!
thank you for not blaring music thru-out video
wonderful explanations
A very good combination of theory and application, well done!
One thing though: with a cut up transformer, the vast majority of the magnetic field lines go from the center bar to the side poles, not around the transformer (9:32). That's what causes the field loops to be closed when an metal object goes across.
That's a surprising amount of holding strength for such a small magnet. Maybe it could be used with cart type frame for a rolling gantry to move things around.
Great ... The pulling power was truly amazing
I've watched two videos on magnetic vices. One created a "magnetic table" that holds the work with the vice mechanically attached to the table. The other used the magnet to hold a traditional type vice to the table. Both have advantages. If you want to get really creative you could try removing the other side of the core as well and see if the drill press table would work as one side of the core making a magnetically held magnetic table. 😎
Great video, excellent descriptions! I'm wanting to build a trommel with an electromagnet Incorporated at some point to remove nails from wood ash.
Thank you for posting!!!
Your experiments flow just as i would do them myself, thanks for the detours
Excellent demonstration of exactly the kind of info on electro-magnets that I was looking for. Thank You! I will be watching if you decide to utilize AC power in demo and it will be interesting to see the pro's and con's of DC vs AC with powerful electro=magnets.
very cool. so small yet so powerful. I made an electromagnet using a 65-pound steel bar and about two hundred feet of insulated copper wire. then hooked it up to a 12-volt deep cycle battery. it was strong, but not as strong as that little one you made. And it got hot quick. Thanks for the perspective. Ill change my design. ; )
You could make an electromagnetic door lock. Also, the reason I am studying magnetics is to make a large magnetic lift for scrap metal. I think you very much for the ideas I have taken from your videos. Great job.
That really helps me understand how magnetic power works thanks for the great vid 👍🏼
I’m looking at building a system for our Jib crane at work to act on a switch to act as a brake system to hold the trolley in place (to a point) and possibly the swing
Big with ups to you for this education , thanks heaps. Your education skills are great with your presentation with details the most important. thanks
Woooow!!!!thats awesome!! That was completely counterintuitive for me.thank you sir.i want to try it with circle core.
The ideas are endless so many possibilities
Great video, good narration and not annoying like some. I came here with the same idea you had, of making an electromagnet vice :).
@9:12 are you saying that the magnetic waves can be compressed and contained in the case and essentially shielded?
Nice, use to lift megalithic blocks in chain out of a quarry the way Ed might have , seriously, it is amazing for the current used.
E-magnets are better for reaping/tearing uses than for lateral/sheering. Just think of those permanent magnet pickup clamps; when you turn them off you basically rotating the load to short the poles...
woow Bryman i really happy see all hobbyist engineers using over expensive flukes
SCHEMATIX
Hi there.
How could I know which is the North pole and South pole in an electromagnet????
Thanks for answering my question...
You can either work it out from basic principles or, even easier, test it with a permanent magnet like a compass. :)
@@Graeme_Lastname
I like good answers !!!!
Thanks for explaining me, however ....could you please say more about 'basic principles'?
Thanks a lot in advance.
@@isabellemarquez4806 Basic principles give you, among other things, the direction of the magnetic field when the direction of electron flow is known. Way to much info for a comment post. B well m8. :)
Very informative video .
Sir , thank you so much for sharing your knowledge .
I am from Sri Lanka .
I want to know to how extent can the coil withstand the heat generated in it? great great your effort
Great video man! You clearly put a lot of effort in it, and it shows. It would be a great electronic lock for your workshop. Not at max current, that would be too harsh for the winding. Or if you make it waterproof, it could be a great magnet-fishing device. Power it up with a car battery. And I sure can use a scaled-down version to get the thousands of tiny screws and bolts out of my long fibre carpet.
Thanks for your lessons!!Congrats from Aussie! 👏👏
If cutting 2 slots and leaving it full size better than cutting it down as all clips shown? More iron larger surface area? Slots cut also would be nice flat and more iron to stick to.
Correct me if am wrong. Electromagnet is demagnetizing, while natural magnet magnetizes ?
I thought u were a Brit but saying 'Bob's ur uncle' confirmed it. U do a great job!
His accent is definitely New Zealand, not British.
‘Bob’s your uncle’ is regularly used in lots of countries, including here in Australia.
What was the temperature of the winding after a few minutes? I would like to know the result of reducing the current to see when the 300kg is released.
That's actually a really good question. I also would be very interested to know the answer.
Yup. Third that. What was temp° and could you please do a reduction in current + a fixed weight # so a ballpark value can be determined! :) thanks lots. Great channel and good on you!
Very usefull video. Thank you. Please try to compile a temperature curve e.g. for 30 minutes of metal machining. Somebody in other video checked the different voltage for input - 3V, 5V, 15V etc. Suppose max weight of metal machined piece cca 10kgs. What a appropriate Voltage by relevant temperture? What about a dBA or vibrations during work?
Thanks ,guy. Thats a cool idea about an electric vice block,like a workbench that holds things still while you're working. You should patent it(fast)!!😉
I love your channel. You are good at explaining things. Also I love your accent and sense of humor. Keep up the good work!
Amazing!👏👏 good job.
You explained very well.
Keep doing...your good job...
Thanks for going thru the steps with a slow/easy understanding informativ learning 💪
Something of note that could be relevant. Magnetic field is proportional to amperage times number of turns (plus or minus difference of losses)
A 200 turns at 4A electromagnet will have almost the same strength as a 400 turns 2A one. Only case by case differences will make one or the other slightly stronger.
Well, there are other factors to take in consideration when choosing one over the other, such as power loss into heat, thermal properties,... but that is more relevant when winding an electromagnet from scratch. The point here is to use easily available material and minimum complexity of modification. Which microwave transformers fit perfectly, plentiful, cheap and easy to power.
If you don't mind a question: how can i determine the max or correct amperage to run thorough a primary winding? Can i use the labeled values on the transformer? I also have a question about height of the legs on the "E" frame the windings are in. Is there a sweet spot in relation to the ark of the magnetic field for an increased gauss value or just closer is better? Lastly since the magnetic field is the same at each pole can I use plates on the side and leave both poles ooen to have the ability to hold items on top as well as hold the device down to a metal surface as needed for a drill press? Thanks in advance for any illumination you might care to offer.
In other words a transformer core contains all the field, as long as the core isn't saturated. Thus external iron doesnt interact with the magnetic fields inside the core. But where the field exits the transformer core, they can interact with external ferus metal.
The field lines are are in a close circuit.
The horse shoe magnets would be having pole pieces when stored for long time.
The torroid core design assures self shielding meaning any other torroid core transformer can be placed just beyond half the diameter distance of the bigger one.
In the case of a solenoid winding to minimize/ avoid interaction the coils would be placed perpendicular to each other and in the case of a third coil, it would be placed in the vertical plane.
You can observe this in the radio circuits.
@@subramanianr7206 if one rewatches the video 5:14 , the original core before being modified was expelling some magnetic fields. That's indicates over saturation that inturn indicats one should run fewer amps due to the fact that the rate of increase in the magnetic field drops due to drop in a decrease in permibility.
en.m.wikipedia.org/wiki/File:Permeability_of_ferromagnet_by_Zureks.svg
But, on rexamination of transformer design, i might be wrong on the saturation current after the core was modified. Transformer design sometimes introduce an air gap to increase the saturation current level. Cuting the core in half introduces a large air gap in the magnetic circuit. Presumptively, that will also increase the saturation current level, maybe well beyond 4 amps. The large air gap now allows for using the core as an electronagnet. But when a piece of metal closes the air gap, the saturating current level will drop.
Take away is that there are more things to consider what current one wants to run depending on the core and how one will use it.
good boy.....same as i use...angle grinder/chop off saw (homemade from furnace motor, and microswitches from microwave).....to re-create MOTs for chargers, welders, etc. made an 18 volt dc supply for cordless tools, converted to corded tools, ...mots rewound for 19 volts dc with capacitors and bridge rectifier.....all work wonderfull....good for you...
what was the reason he choose the primary winding, would you want the wire with more loops
sangat detail dan mudah di mengerti..
saya ingin bertanya,..sambungan jenis apa ( seri / peralel ) jika menggunakan 3 travo
Would you tell how many rounds of the coil, how big the wire and how many voltage do you used to have such a strong magnetic. Thank you.
Thank you for making this video, very interesting indeed. It would be wonderful to know the maximum weight your powerful magnet can carry.
A very nice presentation , thank you
Your video is great, you don’t just explain things really well but you jump in with everyday practical experiments we could all do. That is really powerful and to think it came from an old microwave transformer too, I will use this on my own project, thanks
What if you made like 10 of these and attached them to the loader of a tractor? Curious as to how well it could find old nails and screws for construction site clean up.
solid metal will be stronger the laments are there for AC current to eliminate eddy current. the more turns the stronger the magnet will be, to keep the voltage down you can rap the wire by double or more. because there is no magnetic field fluctuations you don't have to worry about eddy currents or induced back voltage so your wattage will remain low. great video.
Your welds r awesome I loved the video thank u Sir
Damn great video mate, I will now experiment on how to use this in my workshop and for teaching, many thanks, cheers.
You can double the range of your measuring instrument by using a simple tool called a 'snatch block' which consists of a single pulley, You will have to move the cable running thru the snatch block twice as far as you would be moving the load, but you would only be using half as much force to move it.
Just measure that force and multiply by 2 to double the measurement range of your instrument.
That would overcurrent his peabrain.
Please can you tell me how many volts your where putting through the copper wire?
MMF is measured in ampereturns. Thinner Wire equals more turns so the heat developed is independent of the Wire thickness
Excellent video particularly on ease of selection of the transformer. A very cheap mag drill is in my mind I always wanted, and, what I really want to do is a cheap method to have a kill switch on my digger I need to be activated by trips for safety where the "real thing" dam near costs more than the machine. (the magnet will hold the fuel shut off open and another can similarly lock my hydraulics simultaneously on the same electric circuit). Thinking that much power would also work as a lock on the slew control (it's the real one that kills people tripping or catching clothing) in a circuit where if it's not locked the fuel and hydraulic one power off). Been trying to find a way to do this for ages.
great video. I would like to know what would be the formula to calculate the force applied by the current and how it would change? Does anyone has any clue ?
The commercial magnetic bending brakes are using 220 volt electro magnets generating 6 tons force spread out over 48 inches to secure material. Would like to see what you could come up with!
Thanks, can you give links for more info in these brakes? More abt the winding and core sizes ..
What was the diameter of the wire on the big transformer. the small one was just under 1mm.
I'm thinking of maybe trying just the coil without the metal or is it needed... 🤔
Could I disassemble two and put both thick wire windings on the same E?
Good explanation....but what will happen if I use ac power?
I have a transformer from an old welder , It is huge compared to these ones in video it has wires that are bery big on the winding , would that be a good one to use ?
Thank you for this informative video ! I surly could use the electromagnet that you demonstrated, to pull dents out in autobody applications ! The setup that you have would help me GREATLY in repairing my truck !
Won't work. It will saturate.
Amazingly well explained and demonstrated, thank you, many questions answered!!
Try magnet fishing!!
You could put half the current through the magnet and assess the break strength there , or a 1/4
Different steels have different magnetic saturation points, where the magnetic forces pulling towards the iron core is drastically reduced per amp going through the windings. If this point was reached at say 80% current draw of what he is drawing in this video, and then half the current to take a measurement. you only had a 20% drop in magnetic force but half the current draw, thus giving a false measurement. (These numbers are straight out of my ass, and only to prove a point)
Why not use both primary and secondary windings. Connect one wire of the primary to one wire of the secondary and power up the other two.?
Great video! Very informative and helpful. 👍
would make a good dent puller for car bodywork had the idea for years but never put it to practice.
Wow you are amazing, great channel for R&D
So what if you replace the secondary coil with another primary coil in an MOT? You would eliminate having to chop off half of the block, but would it double the power? And would you connect the two coils in series or parallel? And would you reverse polarity on one of the coils? Would it matter in AC, DC?
Sorry about all the questions. 😂
Well I know you can't reverse polarity on one of the the coils, you def want the same, but that a good Idea if you have 2 of the same broken microwaves. Lol. Not sure if parallel or series would create a stronger magnetic pull. Im thhinkin series cause more amps
I had the same question couple weeks ago... after cutting a mot into the E shape I placed another coil on top of the primary coil.. connected 2nd coil to the leads of primary flipped the switch and POW!! i thought fk it blew up .. then simultaneously heard a loud thud and something hit the top of my right shoulder... the 2nd coil I placed on the primary coil shot straight up off the mot transformer.. broke the wires off itself as it headed for the ceiling.... I was dumbfounded to say the least ..
@@codyramos3200 I knew there would be polarity issues, but didnt think about the power involved if connected north to north. Yeah, i guess it would do something like that. Did you try reversing the wires?
@@siggyretburns7523 uh I can't say if I did ... I soldered 1 end of the 2nd coil to another coil to make 1 large coil to work as a secondary coil for a step up transformer... it takes a ridiculous amount of wire to go from 110v to 550v ..
Great stuff. Electro-Vise. Gonna Build One Thanks.
Electro magnetic push broom attachment for work sites that have alot of screws nails that get dropped
What is the purpose of the stacked piece??? I just bought a surface grinder that is missing the magnetic chuck. I must build a chuck and can't afford to buy one. If I simply weld up steel solid and roll the wire , will it have the same holding strength???
I have made these microwave mags before for material handling. They're great for that.
Question: Can i plug this directly to the outlet through a diode to make it DC ?
I dont plan on having it ON for more then 5 seconds.
No. But it doesn't have to be complicated. I reckon a computer power supply would be a good candidate. Limiting the amps is the most complicated part of this project.
You can limit the current, from an AC source, by using use an AC capacitor, on the hot AC lead of primary, and using the Capacitor Reactance Formula to calculate in Ohms.
AC cannot be used to run a electromagnet. Maybe not what you're saying, but the more you know
@@OtherDalfite Wasn't what I was saying. I assumed you would use a rectifier, but, before it gets to the rectifier, you can limit the current using a capacitor on the hot AC lead using capacitor reactance formula.
Example:
108 UF capacitor limits the current due to Capacitor Reactance
Capacitor Reactance = 1 / (2 * PI * Frequency * UF / 1000000)
EX: 1 / (2 * 3.14 * 60 * 108/1000000) = 24.57 Ohms
120 VAC / 24.57 OHMS = 4.88 Amps
its interested lecture , I hope if you play with the volt/amps variation to confirm the relation between v/a/kg , tables and graphs , thanks
great explanation. Wish I had you when doing my apprenticeship. Got there in the end haha. Looks like you could have used an electromagnet drill vice at 6:19... What about an electromagnetic drill press bed so you don't have to use a vice at all. Still looking for something similar for aluminium too...still looking
very impressed!
I was getting worried that we were close to find out what the weakest link of this setup was rather than the electromagnet strength itself. it might have snapped and smashed the car or fly in the air at random.
great demonstration!
Quick question, I have heard there is a need for a diode in the power supply circuit due to induction from the field collapse ( I believe) .
Can you tell me what the item is that I have found on all the microwave I have gathered, it is a black cylinder thing connected to the capacitor then to ground.
Thanks
Awesome advice and well presented! I learned a lot. I do have one piece of advice. Next time don't heat the laminates in the core. They do have lacquer on them for a reason. Laminations perform better in a transformer core than solid iron or molded ferrite powder. It's important for the laminates to be separated from one another with the lacquer. If they touch one another conductively it reduces the efficiency of the core. Next Time start with a new core that will not be damaged by taking it apart or welding all the laminations together into a solid conductive core. In the least don't weld the laminates together. Perhaps put it into a vice while applying some two part resinous bonding glue.
كم من فولت
So how does the liquor get the laminations of those cores that are welded already
@@richardsellars8598 I used the term lacquer but I dont know what material engineers use to isolate the different laminations. I only know that it's a proven fact that isolated laminations create the least resistant transformation. You'd have to ask an engineer how they manage to retain isolation because i dont know.
What is the simplest way to make a small magnetic table so that i can make a small surface grinder about the size of an a4 piece of paper. My financial resources are very limited since i have spent most of 20 years in bed. Most of my metal and wood is what i find near the local garbage dump on each block close to home. I really do not understand electricity though i did completely rewire my house in new york 40 years ago.
Thank you for your time and help.