Building an Electromagnetic Sheet Metal Bender (part 1)

I went down a bit of a rabbit hole on my quest to rebuild by 1956 Jeep CJ-5 and decided to build an electromagnetic sheetmetal brake to bend pieces and parts for the body. I this video, I managed to make something that i would call somewhat functional. Next time I'll make it fully functional.
If you want to build one of these, I'd highly recommend reading through and following the instructions on Alan Bottomley's website: aaybee.au/Magnabend/Magnabend...
Thanks to Craig from @CraigsWorkshop for pointing that out to me and letting me bounce ideas off him while I struggled through this one.
If you like what I'm doing here and find some value in it, consider supporting my work on Patreon. Patrons get ad-free videos, behind the scenes content, and a deep feeling of satisfaction and well being that come with knowing they're helping me create.
/ jeremymakesthings

[@CraigsWorkshop]

You are more than welcome. Thanks for including me, I'm always interested in helping out with problem solving 👍 PS: Shame about the clamping force not being enough, but now you have tons of invaluable hands on experience, I think the next iteration will be excellent.

[@gubr]

Still a nice good magnet to sweep the floor with or use outside to pull new metal stock out of the river bed 😉

[@FelixNielsen]

Reinventing the wheel i the fun part, and in my not so humble opinion also important. If no one reinvents and try to fix that which ain't broken, progress and innovation will stagnate. You got yourself a new sub.

[@scurvofpcp]

For the amount of force you are using with that, you made the right call in what to mount it in.

[@philmenzies2477]

I remember the comment from Fred & Barney. Us positive viewers, whilst probably lax in the encouragement department, still enjoy your efforts. I'm also prepared to bet that that Fred & Barney really are still subbed and watching, just so they can further criticise what they are unable to achieve on their own. Keep up the good work!

[@homemadetools]

Interesting! This is a rare homemade tool build. We shared this video on our homemade tools forum this week 😎

[@jdmccorful]

Rome was not built in a day! Keep going you do GREAT work and I love to see your "workarounds". Thanks!

[@Supraman007]

man, i was really hoping that was going to work better than it did. Good luck on ver. 2.0 !

[@canonsonico3752]

I love how 'rebuilding a jeep' became ' *id love to have that tool* Much love jeremy! Keep doing what you do!

[@Bakafish]

Love this project. As soon as I saw a magnetic break I knew it was the only type for me.

[@yeagerxp]

If you don't have one yet, once you finish the bender you can use a section of that electromagnet bar to make a magnetic drill. 👍👍👍. Thank you for sharing. Be safe 🇨🇦

[@metaltipsandtricks6747]

Good video on a difficult project. Looking forward to your second try. 😀

[@ArcAiN6]

You should take a close look at how electromagnetic chucks are built for surface grinders. In particular, take a look at the use of dissimilar metals, and how they play a role in interfering with, and reinforcing the magnetic fields being created.

[@charliemyres5450]

Good work Jeremy. You haven't made a mistake, just explored the options and there is nothing shameful about that. SAFETY WARNING to anyone interested in getting the transformer out of a microwave. Inside the works is a capacitor (?) that stores a lethal charge of electricity for years. A friend of mine demonstrated it to me one day, by shorting the capacitor to ground; the bang and the flash were most impressive and scary!

[@branchandfoundry560]

This is intriguing! I recently built a 40t press brake and immediately realized it cannot do small box/pan bends because the male die gets in its own way. So, here I am trying to find another build I can bungle!

[@brownell10]

That's the same flavor rabbit hole eternally in front of me. Adding electrons, explosions, lasers, plasma to perfectly good traditional processes... slippery slopes are all I know these days.

[@AJMansfield1]

Regarding those thermal switches: they're almost certainly not rated for very many cycles of breaking inductive loads, but there's two fairly simple solutions to this: - Flyback diodes! (Or if you want to try running on mains AC, substitute a metal oxide varistor aka MOV in for the diode.) This would limit the voltage of the inductive spike produced during switching, hopefully to something the small thermal switches can tolerate. - Contactors! Leave switching the large electromagnets to an appropriately-rated contactor, and instead wire the thermal switches in series with the contactor's coil so the contactor gets released in the case of an overload. Having a contactor also lets you add a pair of latching auto-power-off start/stop buttons to control the device using no further parts aside from the buttons themselves.

[@mickgentry8128]

Still the most refreshing engineering build channel on KZbin. I always enjoy your way of doing it, win or lose!

[@desertTooHot]

Great job sticking with the project! Others would have given up before they even got to the hinges. This is a pretty complicated project that still does work.

[@joell439]

👍👍😎👍👍 - definitely worth the wait. Your resistance to conventional wisdom is always so educational and refreshing.

[@ericmorriscompany9648]

Very interesting video. I had never thought of a magnetic clamping bender. I remember a conversation I had with a magnet vendor where they explained magnetic force in a way that makes sense. For example if you had a magnet capable of generating 50 kg of force and put a piece of steel on it that weighs only 20 grams, the maximum clamping force on that 20 gram piece of steel is 20 grams. He explained that magnetic force is akin to water and the steel piece is a sponge. The steel can only absorb so much force. Any force in excess of its weight cannot be absorbed. Might a thicker clamping bar be needed? You could bolt the first iteration of the clamping bar atop the second one. Plus make more powerful magnets. I’m breathlessly awaiting part 2….😊

[@firstmkb]

Oh I was judging you from the very beginning! You started a tough project, went your own way with it, making use of what you had, and recovered from inevitable mistakes along the way. To be honest, it is not something I would have completed, even if I had your skills. The camera slowly panning towards the wall really had me wondering, until it crashed and I got the comic relief. Well done! And you have leftover magnets for a VERY secure front door, or some kind of sketchy Halloween prank.

[@scroungasworkshop4663]

Hi Jeremy, I just found your channel and really enjoyed it. A few points if I may: you mentioned Alan’s magnabend site and Alan was the original inventor of the magnabend. His instructions show the magnabend uses mains power to create the magnetic force. Alan lives in Australia so our mains power is 230 volts, considerably more than the 48 you’re using. Why don’t you try running 110 ac through a bridge rectifier (electromagnets need dc) and this will give you around 150 dcv. On the magnabend Alan explains that the coils will get hot and to mitigate this he used a switch on the folder that only applies power once the folding arm has started to lift. This means that the power is only on for a few seconds during the fold and therefore prevents the coils overheating. You have nothing to loose at trying this rather than starting again. Like you, I started to build one at home using microwave transformers but went about it slightly differently. The laminated leaves are made of a particular alloy (mostly iron) and are laminated in a way that best enhances an electromagnet so I pulled all the coils out of a dozen microwave magnets and welded all the transformers together to form a 600mm long E shape. I have all the copper wire to make the coil so now it’s on with the winding. Good luck and I hope it works for you. Cheers mate, Stuart 🇦🇺

[@avadavis4768]

Yeah like those magnets can take a LOT more current, not to mention higher voltage. You have a massive epoxy potted heatsink on it first of all, and second off it’s just the primary windings. The simplest way is to make there be a switch that is turned off when bar is down, but then when bar is pulled up the switch is no longer depressed and being happy, it then gets the magnets excited. It’s running whenever you want it to be without even having to switch something on that way. So first mains on/off switch and then that button press switch and then a temperature dependent switch just to make sure overheating can’t happen. I’m sure they can find some way to make or buy a cheap fat rectifier, make sure to try and get decent ripple so maybe some old caps beforehand would be good. Might be a good idea to skip the DIY and just buy a way overkill dc power supply so you can have an overkill dc psu for other projects

[@JeremyMakesThings]

So here’s the issue with doing that- it’s gonna blow the circuit breaker. I figured out the “48v” power supply I got can be dialed in to just about any voltage, and I managed to push about 19a through it at around 70v (give or take, I’m going off fuzzy memory here, and that was all the power supply could take). Scale that up to 120v mains (and neglect the voltage change for rectifying it because we’re doing this math on the back of a beer mat), and you get around 30amps. That MIGHT be enough for the magnet to actually work, but now I’ve got some electrical work to do to make that happen, since the current circuit has a 20a breaker on it. You’ll also see in the next video just how wrong the scale of these magenta were compared to doing it the proper way, which has a much higher resistance (more turns) and runs off a 240v circuit.

[@scroungasworkshop4663]

@@JeremyMakesThings Ill be looking forward to watching the video and I’ll have my fingers crossed that it all works 👍👍👍

[@lumotroph]

I wonder what you could use that magnet setup for now…! Thanks for the brilliant video. I think this type of vid is what makes this one of my favourite channels on KZbin. Keep it up!

[@BG-fm7zj]

Magnetic grinding station would be a great use for this. Just for holding things you are grinding or machining.

[@SupremeRuleroftheWorld]

you should use steel fillter pieces where there is no workpiece. that massivly increases the holding power. that is also what regular magnet brakes are rated to.

[@JeremyMakesThings]

I did try that as well, with no real change in success

[@FliesLikeABrick]

Excited to see all the upcoming portions of the Jeep project. Also, as someone who has a pile of salvaged microwave and HPS light transformers, and needs a sheet metal brake, I'm eager to see this subproject through as well.

[@gubr]

There are special washers for I and C channel with the right angles, so you don't need to machine a flat surface on the inside. I investigated those once because the Heuer vise also has non level mounting surfaces 😎.

[@FliesLikeABrick]

"ran afoul of ohms law" sounds like code for "I cut the transformer apart, plugged it into an unrestricted higher voltage source [like a car battery], and made a short-lived light bulb" :)

[@JeremyMakesThings]

No, just overwhelmed my little 12v supply and it shut down, no harm done.

[@wolfparty4234]

This was really cool, maaan!!😂

[@gutsngorrrr]

It's always great to see the thought and working process, when trying to make something like this.

[@FliesLikeABrick]

"don't want this to be a five part video on all of my mistakes" - maybe at the end of the project you can do a retrospective; as a separate video if desired, after the work is done instead of delaying the work. We all make our mistakes and sharing them helps each other learn faster too, so at least I would appreciate it; as well as your thoughts on what you would do differently (from the plans and/or what decisions you made along the way), etc

[@julias-shed]

Huge amount of work 😱

[@ke6bnl]

I have one of those magnet setups for holding material for sanding on my welding bench, works great for that. I use a 12 volt power to energize it.

[@otherbasis8505]

Some thoughts: Electromagnet's force is proportional to its current. Power is proportional to square of the current. So, to double the clamping force you either need to double the number of magnets at the same current - that will double the power, or keep same magnets but double the current - that will quadruple the power draw. In your case doubling the current is easier, but you will need two 48V power supplies each driving half of the magnets. Of course, if you saturate the iron, you will not get that doubling.

[@mattwilliams3456]

4:00 that transformer looks rather concerned.

[@i_might_be_lying]

Pretty cool and useful project. I wanted to build one myself. In production models I've seen a feature where, when you start bending, there's a momentary switch that supplies much more current to the magnet. Maybe there's a value in trying that first.

[@Buzzhumma]

Build a clamp that's the same as the bottom. A top electro magnet clamp powered up to attract the bottom clamp will have amazing strength .

[@deeiks12]

Awesome idea. From the video it looks like the clamping bar might be bending a bit as well, with the smaller pieces especially. I'd build a triangular'ish frame on top of it to keep it straight.

[@whatilearnttoday5295]

Magnabend are fun.

[@williamsworkshopuk]

Fantastic, as always :)

[@Callum-Long]

love it, sorry it didn't work as expected but the process is beautiful to watch as always

[@AJMansfield1]

Have you tried running the electromagnets just on mains AC? With the core cut apart, the inductance of the coil should be a lot lower; therefore the same 120V 60Hz will experience a lot less reactive impedance and be able to pass some multiple of the rated current even if it was limited by that reactive impedance before. Using AC power there's also an additional heat load to consider, in the form of hysteresis loss, but you have thermal protection circuitry to manage it so it shouldn't be too unsafe to try.

[@HM-Projects]

Time to find a MRI machine in the trash heap, rip out the magnetic bits and use it.

[@TheWeekendWoodshop]

Great project Jeremy. Can’t wait to see how it turns out and how it works.

[@mrchew1982]

Bump up your voltage! With all of that heat sinking and thermal switches you will be fine, and you can use a momentary foot switch if it works to limit the time. Heck, youre not losing anything if you melt it, and might save a heck of a lot of time and money. Id run that sucker all the way up to 120v, that was the original input voltage. And awesome video, thank you.

[@JeremyMakesThings]

It could take a good bit more, but at 120v it would probably draw about 32 amps, so it would trip the breaker.

[@beachboardfan9544]

Should have a ground rod on either end to prevent sheer movement, the magnets should only be drawing the top plate down, not also relying on them to prevent sheer. I'd put two ground rods on either side with a spring in between the top and bottom plate so when the magnet is off the plate lifts a little and when the magnet is on it sucks the plate down.

[@mwnci1000]

With regards to manually stretching metal 22:28 , T.O.T. has super human strength and a time machine so he can go back and correct the mistake before he has made it.

[@whatilearnttoday5295]

@4:00 * Buy vice. * Find the box for grinder and get the handle out of it. * Screw on handle onto the grinder. * Place two hands on the thing which hurts.

[@JeremyMakesThings]

The amount of grinding was so light I didn’t even think about it, but yeah, you got me there, I should have had it in the vise. I generally try to be safety conscious with it (it not only has the handle, but even the guard!).

[@HansWeberHimself]

Great fun.

[@FloridaRCFlyer]

Hey Jeremy, I'd love to see your videos on Odysee!!

[@rallymax2]

Don’t stop trying 😊

[@honeycuttracing]

Very interesting and you had way more luck with those microwave transformers than we did, but in fairness we had that fire about time had collected enough transformers and we where fed up and trashing everything that wasn't necessary, plus our first attempt failed because someone wanted to hook up a car battery to see " just how strong one transformer magnet can be", ended real quick in a smoke show, btw wasn't cause of the fire, that was using wrong charger on lithium ion battery pack and not watching it 🤦‍♂️

[@rhiantaylor3446]

I would avoid trying to switch DC and instead switch mains AC before you rectify it to power the magnets. I also thought you could have some short vertical pillars with corresponding holes in the clamping bar. The magnets pull down which doesn't stop the bar moving back when pushed bending a tight corner.

[@tomthompson7400]

thats a mighty good start to a magnabend ,,, could you not just add a few more transformers ,,, the hinges on the original magnabend are a work of art , thees a site all about the development of the original.

[@CALDues]

Hipster coffee table 😂

[@Qvantum46]

Hi jeremy! Tried to reply to your reply but youtube gave me error and deleted my whole comment :) 1.2mm is probably right since its a jeep also, so looking forward to you solving it!

[@ssskids123]

You have prob already tried this but do you get better performance when you fill the gaps w. The same stock…. I.e. if you are bending 1/8 inch steel, you have a 1/8” gap around the part: put other 1/8” pieces in the gaps. Having more contact may increase the magnetic load. (I think)

[@1973Grejluder]

Highlight this comment ⬆ Yes, this was one of the things that I noticed.

[@rafa_br34]

I wonder if you could build a control circuit(maybe using some MOSFETs diodes and a microcontroller) for this and transform it into an electric hammer.

[@dav1dsm1th]

Is the plan to replace the current electro magnets or to augment them by adding another set on the clamping bar? It would make the clamping bar thicker (probably) but could reduce the amount of "rework" to get something to test. Interesting to see where this goes.

[@JeremyMakesThings]

I’m going to replace the entire magnet

[@dav1dsm1th]

@@JeremyMakesThings cool.

[@KravchenkoAudioPerth]

You have 10 electromagnets if I remember correctly. And you were trying 10 amperes through a test magnet. Are you working with a 100 ampere power supply? Or are you trying to trade voltage for current? I design loudspeakers for a good part of my living. They are electromagnets in a static magnetic field. Push pull linear motor basically. Just thinking! Mark

[@1973Grejluder]

3 comments: A) As already mentioned you should fill in the empty places with the stock the one you're bending. B) The stock 22:27 should be as flat as possible !. C) When bending thick material how about making a swinging C-clamp that you only use when needed.

[@FliesLikeABrick]

I couldn't tell from the outro whether you intend to stick with MOTs or wind on your own cores from scratch? Do you think a shorter version of this would work with the MOTs (using the primary windings as you did in this video) closer together? Like 50-60% of the length of your product in this video, but with the MOTs as close together as you could get, increasing your clamping force per linear inch. I know that may not work for your needs, but it has me starting to brainstorm putting one together here

[@JeremyMakesThings]

I’m going to wind from scratch. I don’t think the MOT’s are the way to go, even for a shorter one. I had them about as close together as I could and still get the wires in, so don’t think you can really pack them in better. Getting off into the weeds a bit, I think the they’re also aluminum wire, which is not ideal for this application.

[@FliesLikeABrick]

@@JeremyMakesThings yeah they are value-engineered to the max. I have a handful of bigger transformers from some high bay lights that maybe will give me more luck as well

[@otherbasis8505]

What's the power rating on that 48V power supply? My guess you need at least something like 650W.

[@JeremyMakesThings]

It’s a 25a power supply, but only using about 12-14a, so somewhere around 600w By contrast, the directions call for a magnet that uses around 2kw.

[@rayg436]

Use the other coils from the microwave transfers

[@philanderingwhitecollartra8281]

mag drill requires 1/2" steel to have adequate adhesion... i jeep a 3/4x6" fb to clamp onto stuff with mag drill..

[@chopper3lw]

Oh hell , that sucks! can you try whacking up the current? I mean what harm can it do? ( I was initially wondering if potting the magnets was going to cause a heat problem. )

[@93Martin]

Tried to go full TOT, but your grip was just a little off. Gotta go back and watch closer next time to see how he does it

[@robertlunsford1350]

You just need a forge and a hydraulic press to make it wider. Next project?

[@djkommando]

Did you consider putting dowel pins in the end of the clamping bar? That way it can't slide and will always index to the same alignment with the bending bar.

[@JeremyMakesThings]

No, the big advantage of this style of brake is the ends are totally open so you can hang work off the ends. It’ll make sense once it’s working properly and I can show it in action.

[@danburch9989]

I think that would be a good idea though if you know you won't be bending anything longer that its width. The maximum gauge thickness of the sheet metal is limited by the design no matter what route is taken.

[@GenAfterNextTactics]

I wonder if you could have pushed another 40 or 50 volts through those windings to get more out of your 10 amps?

[@jjjannes]

What? That does not make sense, the current changes if you change the voltage.

[@GenAfterNextTactics]

@@jjjannes yeah, exactly

[@Bobs-Wrigles5555]

Just a thought, but would turning the transformer core magnets 90 degrees change the way they hold the clamping bar? The thought behind that is, the bar is rolled in such a way so that the metal particles are aligned along the bar not across it, if you were to swipe the bar enough with a magnet to try to make it a magnet(ie like you do with a screwdriver), the poles would be at each end not to each side. 🤔🤔???

[@garthdaddy7438]

Would probably be better and alternate the winding polarities so that the flux is connected between transformers.

[@Bobs-Wrigles5555]

@@garthdaddy7438 I gather you're thinking the cores also have to be turned 90 degrees to do this ie continuous alternating poles the length of the bar?

[@smallshoptalk589]

SO, From where did you get all the transformers??????

[@gsftom]

Did Fred and Barney check with Wilma and Betty?

[@denirodarkqwerty]

this old tony vibes

[@tumbleweedtumbleweed]

Peg it on each end so it doesn’t slide back? 🤔

[@craiggardner5347]

throw more current at it at the time you bend.

[@renatomsgomes]

What discord channel u use?

[@DavidHerscher]

I feel like I recognize all of the words you’re using as being English words, however the order in which you’re putting them together is Greek to me. IE; this electro magnet stuff is so far over my head that you might as well be in outer space… 😅

[@SomeMorganSomewhere]

I wonder if electromagnetic door locks might be a better choice for the magnet, they're available at reasonable prices from the usual suspects.

[@glennmoreland6457]

Turns = voltage Cross sectional area = Amperes ☹🇬🇧

[@rogerdeane3608]

A lot of work, out come disappointing, but Interesting as always.

[@otherbasis8505]

Wait a second. Those are microwave oven transformers, right? Aren't they, like, 600W _each_ !? So you can actually drive the hell out of them?

[@JeremyMakesThings]

Not without blowing a breaker.

[@otherbasis8505]

@@JeremyMakesThings Right, right - they _move_ 600W, they do not dissipate it (food does). Still, I think you can push much more current through them for short duration.

[@JeremyMakesThings]

@@otherbasis8505 hm…if I split them into two sets in parallel, ant turn down the voltage in the power supply a little bit, I should be able to push about twice the amperage though them and still be ok. Might try that.

[@christurnblom4825]

Jesus! First time I've seen your channel and the second time in two days and the second time ever, that I watched a KZbin video where at the end the thing didn't work. ....which I hesitantly predicted in the first quarter of the video. Is this a new trend on YT? ...making things that fail to piss us off & waste our time? That failure was for YOU to learn from, not the rest of us. As they say "You can't please everyone" I'm one of them. Next time, please add "which doesn't work" to the tittle. You're probably a nice guy but... wow! I think you've lost a potential subscriber here. also... Why not just thread some holes in the magnets or use insert if the Es & Is create a problem with threading, so you can lock down the form/clamping bar?

[@JeremyMakesThings]

It's not that it doesn't work, it's that it doesn't work well YET. The title of the video says that this is "(Part 1)" which implies an incomplete and likely unsatisfying conclusion, and also that there will be a "Part 2." Part 2 is in the works, but these things take time. And honestly, yeah, I'm not satisfied with how this project/video came together either. I would have much rather it was a nice, tidy successful 20 minute package where everything worked well the first time, but that's not the reality of how these sorts of projects go most of the time. I'm sure if I wanted to, I could have waited until everything was working perfectly, and then package it up into a perfectly-polished-for-social-media video, but I'm much more interested in sharing the process than the result. I find that a lot of people are afraid to ever even start on something because they don't "know" how to do it and are afraid to make mistakes, but I'm not afraid to mistakes, or do to something like this that I think might not work just to see if it might work. I'm also a lot more stubborn and persistent than most people, so I want to show that if you keep trying you can make cool stuff even if you only have a vague idea what you're doing and can learn from you mistakes. I also disagree that my mistakes are only for me to learn from. If I had seen this video before I started, I would have certainly gone a different route. We can agree to disagree, and maybe this channel isn't for you, but that's where I'm coming from. In terms of the machine and adding hold downs, the huge advantage of these magnetic brakes the top is completely open, which allows for much more complicated bends to be made than on a traditional sheetmetal brake. For example: you can hang a work piece off the end and have a tab on one side that that's bent down and one on another side that's bent up. I wish I had been able to show it in this video, but that's not the way it goes sometimes. It'll make more sense in Part 2 when (not if) I get this thing working properly.

[@christurnblom4825]

@@JeremyMakesThings Hey. I'm glad we can agree to disagree. hahaaaaa..... I guess I should shun myself publicly for openly admitting that I just wanted to watch this in case i can just copy your work for the price of a mere sub. I still don't understand what people can learn from watching what DOESN'T work but hey, I've been taking shit apart & tinkering with it since was 7 or 8 which is almost 40 years so maybe I've lost perspective. I give you credit for doing a channel though. I've thought about such for a few years but only have one video to show for it ...ten years ago! lol I'll give you another shot. Keep being stubborn. ...I mean PERSISTENT!!

[@christurnblom4825]

@@JeremyMakesThings Also... if I'm understanding you correctly, the problem could still be solved with the previous recommendation (bolt holes in the magnet) if one were to slot the clamping bar. So you have bolt holes in the magnet & longer slots in the bar to adjust the position even the angle if needed. But that would defeat the point of getting the end product exactly the way you wanted it. Which sounds like the way you are describing you intentions. ...and I get that. I've just become more pragmatic over the years & if pride has anything to do with it, I've learned that pride is not really that valuable of a personality trait. in most ways. In some ways pride is a good thing but in most ways, pride is a good thing to learn to swallow. ...Probably not for the original intent of your video though. If you were 100% intent on making this thing work in the way you wanted it to in the beginning. Go for it, I say.