Build a 1000W Battery Spot Welder Using a Microwave Transformer | Step-by-Step Guide

[Music] [Applause] [Music] this video is sponsored by pcb go go hey guys max here this time we're going to make a spot welder from a microwave oven specifically a spot welder for welding battery packs together and the core of this project will be a microwave oven transformer one i salvaged from a broken microwave about a couple of months ago do keep in mind that these things produce a lethal voltage in their original state but we will be rewinding the secondary coil to produce a really low voltage and a really high amount of current so it'll be safe to touch afterwards my main purpose for making the spot welder is to make a battery pack for my e-scooter so that'll be a fun project coming up soon as well anyway let's make this beast of a spot welder let's get started so from this very same 1000 watt microwave i pulled out all of these nifty parts right here laid on this table consisting of the transformer itself magnetron cooling fan control panel and a couple of other components guys just before we move on i'll introduce the sponsors of this video pcb go go pcb go go is a pcb manufacturing company and turnkey pcb assembly provider providing you with quality printed circuit boards and assemblies based on your own tailor-made circuit designs for whichever electronic projects you want to pursue they offer both partial pcb assembly and full turnkey pcb assembly which means they ensure customized manufacturing to every customer's needs along with reducing your effort and time by providing for the assemblies with their component sourcing as their brand new customer you get a 50 coupon and on top of that you get an additional limited time coupon which is given to all customers check the links in the description below this video and try out pcb go go today so from the parts i got out of the microwave i'll be using a momentary push button switch cable cooling fan and of course the 2000 volt step up transformer here's all the parts and supplies you'll need to get started with this project the first thing we will do is saw off the upper winding also known as the secondary winding of the transformer this is the winding that delivered the 2000 volts but not anymore once you've sawed off a piece of the secondary winding it should look like this interesting to see that 3d pen art type effect when you push on either side of this freshly cut spool of wire now let's drill out most of the secondary winding of aluminum wire from both slots [Music] [Applause] [Music] once you've completely gotten rid of the secondary winding the transformer should look like this and oh boy the mess this procedure creates be sure to add some strips of tape to any sharp edges of the transformer before rewinding now let's wind two turns of this four gauge enameled copper wire creating a new secondary winding on this transformer once you've rewinded your transformer be sure to test it out and to see that it can make some sparks before continuing on [Music] shove some pieces of cardboard or plastic between the ceiling of the iron core and wire for the casing of the spot welder i'll be using the shell from an old ups inverter the casing of your spot welder doesn't have to be made from metal necessarily it could be made from plastic or even wood [Music] once you've shoved the power input cable in through the case strip the wire ends add a bit of soldering tin and solder a 10 or 15 amp fuse to the neutral wire and here we begin with the electrical circuitry connect up the fuse to one end of the primary power input this is the 15 amp on off switch we'll be using solder some wires coming from it and install it in the front panel of the case [Music] get the transformer to sit as close to the front of the whole thing as possible so that the wires appear to have enough length to them mark and drill some holes for the transformer's bottom plate to get bolted to the case solder one end of the switch to the cable's hot wire and then pull through an on wire over the transformer to the other side of the case for the fan bolting the ground wire to the case ensures that this whole appliance is grounded next we will get this fan hooked up to the unit [Music] since i knew the fan blade would not fit and wouldn't be able to spin with the cover on i had to trim it a bit check to see that the fan is spinning fortunately with the cover slit over the fan it doesn't seem to have any problems spinning next let's sort out the cable that'll be going to the push pedal it'll simply act as the switch cable pushing it through the front connect one wire to the remaining terminal of the primary coil and the other to the on side of the switch for additional safety be sure to add heat shrink tubing or electrical tape to any exposed terminals and wires to give you the ability and choice of either having a shortened cable or a longer cable we're going to connect everything through these dean's connectors so this will give us the option of either having it as a hand pedal or a foot pedal push pedal there we go with the longer one connected we can have it as a foot pedal cutting a 20 centimeter section of the square bar of wood we will turn this into the spot welder's arm the best way to get it secured onto the front of the machine with a hinging action of course is to use an actual door hinge i had to modify this door hinge a little bit so that it didn't get in the way of the switch [Music] after securing the hinge onto the front of the unit we'll now drill a hole in front of this square bar of wood after painting it in the color of your choice you can secure this piece of wood on with this modified metal c-clamp then we're going to make the spot welding tips from this three millimeter solid copper wire be sure to curve them into hooks and also sharpen the ends up pretty well mount the wire leads and tips onto the wood with a bolt on each side if you find that the welding wire is hanging around a little too loose then you can secure them to the wood with some zip ties add on a comfortable welding handle and then a retraction spring for the little hook that the spring goes through i'm using a bicycle spoke now let's make the spot welding machines push pedal which will be housing the 15 amp momentary push button switch and for fun you can even add on a push me sign hooking it up to the unit itself we are ready for action as you can see there's plenty of airflow flowing in through the machine bypassing the transformer and back out cooling the whole thing just to reassure all of you it's outputting such a low voltage that it cannot harm you so it's safe to be in contact with the tips while welding wait a minute we're missing one more thing let's give this machine a handle after having done that finally let's slide on that cover you can also give the machine some foam feet to stand on and voila with all that the spot welding machine is finished please roll in that montage [Music] oh [Music] so for spot welding the cells together i'll be using these nickel strips you can purchase these online through one of the links below so for this demo i'll spot weld a couple of batteries in parallel and create a battery pack using this spot welder so in my first attempts it didn't seem all so hopeful the nickel strips i tried to weld just seemed to get stuck to the tips or when they did stick to the batteries they would turn out looking not so attractive but here i'll show you how to fix that so since i was using three millimeter copper wire that wasn't actually pure no wonder the nickel strips want it to stick to a very similar metal so i replaced it with this pure copper wire instead you may not see very well but in the core of the previous tips you see what basically is just another type of metal wrapped in copper whereas the new copper may be a little hollow but it does the job so for insulating the 18650 cells i recommend adding on these rings to spot weld with such a spot welder as this one that doesn't have an integrated timer just make a very brief tap on the push pedal and if the metal strips don't stick to the batteries then you can hold down for a little bit longer until the point you see this glowing ember the spot welds look much cleaner than my first attempts i know they may not look perfect but they're just fine for diy needs oh and they sure do hold up pretty well the spot welder ended up weighing almost 6 kilos but that doesn't stop it from being easy to move around and store so looking deeper into the transformers equations knowing that it gives out 2.2 volts on the secondary side we can confirm that by multiplying the primary voltage by the amount of turns on the secondary side divided by the amount of turns on the primary winding so with this modified transformer we get a turn ratio of 50 to 1. keeping in mind that the power on the primary winding equals the power on the secondary winding we can divide the transformer's power and wattage by the secondary windings voltage to get the secondary winding's current output in a video from another youtuber diode gone wild there you can learn about the changes in the transformers power when spot welding or when shorting the leads together and what really goes on so to wrap things up about this diy spot welding machine for batteries personally it makes quite the decent battery spot welds they may not be perfect but they're great for any of your diy needs hopefully you guys can also recreate it and simplify the making process of your own projects if you guys enjoyed watching the video don't forget to leave a thumbs up share the video with your friends comment down below sharing your opinion about the spot welder and subscribe to the youtube channel if you're ever considering and financially supporting my work then feel free to donate to my crypto wallet there's a link in the description below this video once again don't forget to check out pcbgogo.com all the links about them are in the description below with a special coupon offer thanks for watching guys and i'll catch you around peace [Music]

Channel: Max Imagination

Views: 30,604

Keywords: max imagination, diy, spot, welder, welding, spot welder, spot welding machine, machine, welding machine, точечный сварщик, сварочный аппарат, сварка, maquina de soldar, máquina de soldadura por puntos, homemade, homemade spot welder, at home, make at home, how to, how to make, battery spotwelder, battery, for batteries, 18650, 18650 batteries, 18650 cells, push pedal, 1000w, microwave, microwave oven, mot, transformer, microwave transformer, foot pedal, tab welder, spotwelder

Id: 2gB0P1_M59E

Length: 15min 10sec (910 seconds)

Published: Fri Nov 19 2021