Convert Welder from AC to DCEN ✔

hello this is Mark and welcome to another one of my videos thanks to all my subscribers for watching and being a subscriber and if you're not go ahead and feel free to click subscribe and thank you I'm gonna turn my Chicago Electric Harbor Freight welder 90 amp AC welder which basically runs on 110 110 volts and welds in AC I'm going to convert it to a DC welder using the tips and guidance of Matt here on youtube if you search for converting the Harbor Freight welder from AC to DC you're bound to find some of Matt's videos they're quite a few of them and they're very helpful and so based on what he did I'm gonna try to model my retrofit after what he did he also answered one of my questions that I posted on one of his facebook videos okay first up in the parts is this giant blue malory capacitor it isn't very heavy I see it's got a small little dent in it hope that doesn't hurt anything might have happened in shipping this was shipped in an envelope similar to this one so that could have happened in the shipping but anyway it's a twenty-one thousand microfarad and 100 volt DC rated max surge of a hundred and twenty five volts DC and in this envelope there are three resistors that I'll use to bleed the system down and we'll open that up later and here I've got the heart of the whole thing which is this rectifier it's an AC to DC rectifier this is a three-phase meaning it has 3 AC inputs in the back 2dc in the front they are marked on both the schematic diagram and on the post themselves positive negative so you don't get that mixed up and for regular to phase AC you can just pick any to any pair of these that you want and it'll go through the diodes and end up being positive and negative on this side I think this was seven dollars and some change delivered okay and then I've got a hodgepodge of other parts including some six gauge wire we've got six feet of that should be enough got some quarter-inch copper tubing connectors or joints and I'm gonna use those as crimp connectors okay got four of those four crimping any of the wires together and I'll also use some solder with that to hold them got miscellaneous flat washers lock washers and bolts and nuts to mount the rectifier bolts and nuts to connect the wires together using some connectors like these four six gauge wire I've got a couple of packages of those a couple of packages of washers to go with this as well so all in all it's about maybe 40 dollars worth of parts but tobe some parts left over I'm sure and basically the whole reason I'm converting this over is first of all the weld quality of the AC and I on doing some AC welding and a few minutes here to do a before and after but the convenience of having a 110 plug on the end meaning that I can take this virtually anywhere and plug it in even a thick rugged extension cord will handle the the amperage this is pulling and instead of using to 2110 so it makes it more versatile for me and have it weld in DC instead of AC I'm hoping as the videos have shown online that it welds much better in DC mode with the electrode or the wand negative and the clamp positive that's what we're going after and that's known as a DC en direct current electrode negative set up the welder settings are on maximum wire speed is at seven currently the machine has point zero three five diameter wire in it flux core wire o three five okay so I'm going to do a line on here using the AC mode okay there was twelve seconds of welding okay well there's what the weld looks like you can see it's made of blobby and really much of a continuous weld to it there is some splatter that's stuck onto the rotor some of its coming off most of its sticking so that's what the AC welding has done okay I got the holes marked to drill to bolt the rectifier inside the cover okay well basically scratch what I told you about putting it on the inside I've decided this is the this was the plan all along actually so I've spared you the mistake of showing you that I was going to put this on the inside so pretend that didn't happen and now I've got these little fin pieces all over the garage floor here but this is where I want to bolt up the rectifier is on the outside okay the rectifier is mounted it's a little bit crooked it's not exactly straight and if there's anything not perfect about this project it's because I'm not perfect myself but anyway I've been these tabs down a little bit here let some more air flow so I'm hoping air flows around it from the fan from the inside out but also I mounted it vertically because the fins are vertical heat rises so it might conduct to the air and in a flow up across the fins and in in a vertical motion to cool this rectifier should it get warm okay and put the screws back in I took off the top screws off the back here to lower this down bend it back down gently also when drilling the hole you have to be aware that you don't want to go through the hole and right into your transformer coil so okay little progress update I've spliced the wires using just some lamp cord that I had laying around so that I only took a few inches to extend for the blue wires because they're just not long enough to once once the motors been put on the back side of the unit which I did and I'll show you here what I plan to do is buy another piece of metal and you make like a bracket back here drill a couple of holes and put a metal brace back here so to speak to kind of protect the motor from any rear rear-end bumps or something but I can definitely feel the air being pulled in around my hand through the grille back here and inside yeah there's a nice airflow now in fact I've got some cobwebs wiggling down here in the bottom the base of the unit so I know this is going to draw more air in what a mess this has turned out to be there's screws everywhere down here here they go to the covers but I'm just gonna pick it up as best I can for now so I can get the door closed and pick up where we left off hopefully tomorrow okay progress update I've had to remove the collar here from the feed cable so I could remove it and took the two screws out of the front so I could tilt this forward and I gently had to unplug a couple of wires one at a time to go for this black wire that feeds the gun which was on the other side of the circuit board I unplugged first this wire the white one then the black one down here and there plugged in pretty solid but if you're gentle and don't bring break the circuit board you can get it out so I removed those one of the time so that I could swing the wire from this side of the circuit board to this side of the circuit board so that now I can get at it to cut it and make my connections when it was on this side of the circuit board it was very difficult to even reach it so that's what I came up with very gentle though there are a lot of short wires attached to the circuit board that go to different things that don't give you a lot of length so you don't have a lot of pulling room here and you could easily damage anything on this circuit board if you're not careful so now I've got this exposed for the gun down here is the wire for the clamp so it's time to do some cutting and splicing okay well time for another progress update I've got the rectifier connected up with the bolts and the connectors crimped onto the wires the six gauge wire which may be 4 gauge would be better it's very close to the same size as what is in the unit but I've got the AC wires feeding the AC part of the rectifier the DC comes out for instance here's the positive which goes directly into the wire down here that goes out to the clamp and as you can see I've also got the maybe you can see the capacitor wire comes down around and takes a corner and also feeds straight in the direction of the clamp wire and the electrode negative goes to the gun that's this wire and here's one from the capacitor ties into the short little pigtail wire that goes up to feed the the gun electricity the negative that we're looking for so everything's wired up I've got the capacitor strapped down with these zip ties through holes that were drilled in the top I also drilled a couple of holes for the capacitor wires to go down through big enough so that the wires aren't really the outside edges of the polls I'm not worried about any shortages or anything like that from that so it looks like I'm ready to start buttoning it up and seeing what we have for a welder now well I said earlier in the video I believe that I'm not perfect here's a sign of it I actually swapped the covers side for side they're on the wrong sides now so I've got the extra part of the side covers sticking out on the back now which looked odd right off the bat and well it might help protect them the motor until I get a bracket across here but and that means the front is just smooth all the way across now maybe that exposes the buttons to damage if it comes up against something on the front so that's something I got to be aware of from now on as you can see the front cover doesn't line up with anything anymore because it's back here now so it's too late to switch the covers around now because the rectifier is mounted on the other side so another thing I want to point out is I bought six feet of number six gauge wire and right there that about two inches is all I've got left of the six foot piece of wire let's get to the moment of truth and see what happens I've got the unit plugged in the setting is on maximum amperage the wire feed speed is set at number five let's turn on the power and see if it blows up first of all power is on the fan is blowing air through the unit I can see the little pieces of grass and stuff on the ground around the unit moving so clamp positive electrode negative okay well upon first inspection here's the DC weld here's the AC weld there is noticeably less splatter on the piece but the weld now that I've wire brushed it off looks about the same as the AC oh it's far did you see that I did not pull the trigger and there was a spark but from the capacitor but now it's gone well it's definitely welding more consistent there's still fewer little bb's splatter stuck around on the piece and the welds themselves look to be more continuous again well speed is on five I'm gonna try to turn it up to six okay let's try six [Applause] well folks as you were watching the weld right there and it quit that is where the rectifier blew its guts apparently it did get very warm I tried measuring voltage from the the lines AC to DC I was getting very little with it hooked up I unhooked the wires from the rectifier and on the low setting I was getting 21 volts AC on the AC side nothing on the DC and on the high setting I was getting 27 volts across the two wires when as long as they weren't on the rectifier itself but anything to do with rectifier especially this leg to this leg and also this leg to this leg which is this is the positive up here it is showing a short and just for the sake of the video here is the weld the DC weld that was in progress before it crapped out right right here it doesn't look that bad really I mean there's some spaces here where the wire feed wasn't quite doing what it should and I do have the wire feed set the tension set very low so that the motor will slip the rollers will slip instead of bogging the motor down I'm trying to preserve the motor that way well gang while I'm waiting for the mailman to drop off the new bridge rectifier I want to show you some other modifications I've done besides putting the fan on the outside I took this piece of angle steel flattened it out a bit it still has a little bit of roundness to it but drilled holes in each end after I bending them to fit and put bolts through and now I've got a nice secure bracket to protect the back of the unit the motor and also with the help of mini Thor I flattened out the louvers on what would be near the fan the middle and since these are backwards now this used to be the the back but now it's the front so I flattened out the back to louver panels and just leaving the front open so that the air will have to sweep past the main transformer and other parts before it can escape out the the front louvers here Hey look everybody gets the mailman time to get the new part and put it in the machine alright check it out peeps mailman was just here dropped off the new AC to DC rectifier this one is a 150 amp single phase not the three pay there it is it's got a nice metal heatsink on the back we've got markings for the diagram 150 amp 1600 volt rating here's where the AC goes in you can see the little squiggly lines on there at least I can and on the front we have markings for negative and positive so let's put it in see what happens there it also got my 160 ohm wire wound resistor in place to bleed off the capacitor between welds we'll see how that holds up so I think it's ready to button it up and try it out and let's see what kind of a weld we can get let's put the machine on maximum i've got wire feed set 2 to number 5 again max setting wire speed number five and that doesn't look too bad to me the welds seem to be very consistent that's what the weld looks like maximum setting and wire feed number by let's give it another go [Music] okay we're back on the welder project here and after welding again this is with Oh three five wire even this big piece of metal here that was just a scrap metal piece got really warm to the touch and an engineering friend of mine suggested that I used aluminum make a big aluminum heatsink for this side for the the bridge rectifier to dissipate the heat better so I'm gonna remove this plate and replace it with this piece of aluminum it's a little dirty I gotta clean it up but and else we got to cut it to size but looks like it'll size up pretty good okay so what I've done here is I removed the panel of course I remove the other block and separated the bridge rectifier from it cut this pretty much - sighs if it's pretty good drilled a couple of holes then I took the cutting wheel and I cut all of these fins away to give this panel more access to the air going by to cool it from the inner fan before it exits out these fins okay so sparing you most of the gory details I got the bolts back in got the plate mounted it's got plenty of breathing room behind it and so let's give it a test drive and see what it does I'm going to use o3o from now on but this is all the store had at the time and I'm thinking it's just a little too thick for this machine for a 120-volt machine maybe you'd be okay for a 220 that the amps could go up higher but as soon as this pool runs out I'm going back to oh three oh no more oh three five [Music] rush off towards the end of it wasn't looking too bad is melting good it's yeah it's putting out good heat this is still plenty warm let me check the plate okay the aluminum heatsink plate on the bridge rectifier is a bit warmer than it was but still I can leave my hand right on it a big difference over what it was before and I've got good airflow coming out of the machine so I'm not worried about it overheating anymore that seems to have done the trick that's really spreading the heat throughout that aluminium plate okay well all in all I've got some good melting going on at the end of the gun the more practice is needed obviously to get a good weld a good bead going but it does seem to have enough amperage to melt even this oh three five wire for me it's important that I used a 120 volt welder that I could plug in in any outlet and and that's why I did this conversion and that's why I started with this AC welder in the first place is because I could plug it into a regular one 120 outlet this one again is only rated up to 90 amps and the bridge rectifier I've got it it now is rated for up to 150 amps and so far especially using that aluminum heatsink it seems to be holding up very well and seems to be a solid product now that should last for quite some time I hope anyway comment away tell me what you think

Channel: Mark Young - Outside The Box

Views: 108,890

Keywords: convert welder to dc, convert harbor freight welder to dc, harbor freight welder mods, harbor freight welder dc conversion, harbor freight welder dc mod, harbor freight welder, cheap mig welder, ac to dc welder conversion, harbor freight welder any good, harbor freight welder 90 amp flux core, harbor freight welder 90 amp flux core mods, harbor freight flux welder, harbor freight welder upgrade, chicago welder 90 amp, harbor freight dcen conversion, welder fails, youtube, how to

Id: iAcbMg8l2A4

Length: 22min 47sec (1367 seconds)

Published: Wed Nov 08 2017