Items bought through Ebay: ONE Large capacitor with values of Mallory CGS Series 21000uF - 100VDC . ONE resistor with value of 160 Ohm 10W 1% Resistor Silicone Wirewound. ONE Bridge Rectifier of MDQ 150A Single-Phase Diode Bridge Rectifier. Items bought elsewhere: 6 feet of 6 gauge wire (not much to spare, so 7 feet of wire might be better). I used FOUR 1/4 inch copper connector tubes to join wires together with solder. TWO packages of 6 gauge wire terminals for connections to the bridge rectifier and the large capacitor terminals. Various sized nuts, bolts and washers to mount the bridge rectifier and to use on the connection terminals.
Thanks! This is a Mallory CGS Series 21000uF - 100VDC. I measured the DC voltage coming from the welder on its high output setting and it was less than 30 volts DC, so using a capacitor rated for up to 100 volts DC "should" be ok.
I've just got to say that I've owned a HF Flux125 for about a year now, and that I have taken some professional welding courses at a local trade school, and I have no problem with the machine, my weld performance , overall strength and "eye" appeal. I can certainly attest that when I 've used superior shop machines in the DCEN mode, that the weld quality is better, no doubt. The videos I am seeing on YT who are doing DC conversions, can't seem to run a decent weld to begin with. So before all you Flux125 owners think you need to convert to get a decent weld, consider practicing a constant 1/2" "stick out", 5 - 10 degree drag angle, correct wire feed speed and voltage setting (hi -lo). I had to tweak settings for different steel thicknesses. I had to play with wire feeder tension. I make sure my base metals are well prepped and fitted up. All these factors can make a big difference in weld quality. The main modification that I think would be quite helpful, would be to swap out the ground clamp to a bronze unit that HF sells. I just haven't yet on my machine, because it welds quite nicely for me. Oh and I use Lincoln NR-211-MP .035"wire.
Thank you. I just stumbled on a few of these videos and was like "oh shit do I need to risk melting something down messing with wires to make my little cheap welder work better?" 🤣🤣 I've welded three times, made a couple little burn pits. Seems to be fine I know I know nothing so it'll get there.
Oh wow.....really impressed with you starting out feeding your ego with your welding courses bragging....lol. The fact of the matter is some of us can weld AND a DC fluxcore welder will always outperform a cheaper AC output one regardless of how well you think you can weld. So puff your chicken chest out some more and tell us seasoned welders how you can weld now after taking your little welding night classes....lol. Some of us have been welding since we could walk and have many, many hours under our belts and we are not ragging on less experienced welders.....unlike YOU. You and your overinflated ego can go kick rocks as far as I am concerned. Anyone wanting to upgrade their AC output flux core welder to a DC output will only improve their welders doing so.....that is the whole reason behind this video. I always laugh because regardless of the video or subject there is ALWAYS at least one egotistical A hole in the comments section....ha ha ha ha ha ha!
You have illustrated "Third one is the charm". Since you did not convert three welders you did not get the perfect conversion but you combined what works with what not to do with enthusiasm and a good voice. Good luck with future videos.
Thank you Stuart! I know it was a bit of a hot mess, but the end result, with the additional aluminum heat sink, is still working just fine, even with 0.035 gauge wire.
Agreed, I own a similar welder, and have used it to so a lot of welds for friends and stuff, and I have gotten a ton better. I can lay dimes on these cheap AC machines, and now I just bought my first TIG welder. You can tell he is a new welder lol, but with practice comes experience.
Loved the video. You showed mistakes, lessons learned, and adjustments. There are more professionally edited videos out there but they only show the perfect parts. You have a good attitude and I am sure you are welding has greatly improved.
For a heat sink to work at all it has to be in direct contact with the metal it’s wicking heat away from. Get that sheet metal out of between the rectifier and the aluminum sheet and apply a little heat sink compound and use a small cheap fan to blow more air over the outside of that plate since it’s your heatsink and surface area is so low without fins you’ll need to pass more air over it so a small table fan or clip on fan on high should do it. Low duty cycle that way too. Look up how to replace a heat sink on sun v120 servers. Simple and use same principles thermal conductive paste and tension against the metal of the rectifier and the “heatsink”.
I used that same brand rectifier, got the 200amp, it works great! It's a bit slower to strike, but once bead starts the weld lays down and penetrates base metal much better. Also after welding for ten minutes straight, the rectifier wasn't even hot!
got my welder today and i didnt do mods other than to practiced and my weld are flawless dont need to convert to dc when the welder works perfectly fine
that's why we all used the 150 amp BR to begin with, at 100 amps there isn't enough head room for the peak amperage. also the reason your AC welds had so much splatter is because you had the wire speed up too high, were moving too fast and had too much stick out. As long as you know how to weld the HF 115v flux core welder is perfectly capable of running a consistent bead in AC form, the main reason for the DCEN conversion is weld penetration . the conversion creates another problem which you didn't address, because of the hotter arc higher current flow with DC, it caused the current for the wire feed motor to sag which in turn causes the wire speed to pulse up and down. AS for your welding in general you need to slow your wire speeds down, start a puddle and move the puddle along as you weld and keep your stick out down to a half inch unless your are welding really thin metal....
Welding cast iron instead of steel may be part of the problem with the welds. I have converted my older style HF 90 amp welder, and I was able to fit all my parts inside. I moved the transformer over about 1/2" to the right, and rotated the wire feed control board to the top. I installed a transformer for wire feed and I also installed a ground dinse socket and plug, moved the power cord to the rear and installed an adapter block for a Miller m10 mig gun. I also installed a higher volume fan with the heat sink on an angle on the left side in front of that fan. I'm hoping to finish wiring the rectifier in the next few days, and give it a try. I will have to power this with a generator since my shop is on an Amish farm with no electric.
You would get better heat rejection from the rectifier if you attached it directly to the aluminum plate(alongside the center section you have it attached to in the video.) I would suggest using some 'heat sink paste', just a dab, to improve conduction. As it is, the only connection is through the 'strip' down the middle, leaving 80%of the heat sink area floating in the breeze,touching nothing. The Al will conduct so well it does not have to be centered in the slab, and you will get so much more conduction area it would not make any difference anyway, so set it to one side or the other. I have an off-brand, and plan to do a similar mod. I bought the same rectifier, and then bought the second one you have before doing anything. The second one was not available from ebay or amaz, so I went to aliexpress. I have to figure out where to put it in this unit which is not layed out the same. I'll get there.
Thanks for making this video. I have to say, there is more to welding then putting the tip down, squeezing the trigger and moving the gun. This is an older video so maybe you have had a chance to practice a little. You’re after the mod weld should have been a fairly good bead.
A great video, thank you for posting, I'm sure brake discs are cast iron, you could probably get better results from welding some angle iron? I'm thinking of doing this mod to my old SIP arc welder.
I used a 20v transformer which peaks out at about 23 or so, so it runs it well. Interestingly, I tried a 24vdc power supply, but the range of control was not much.
I like your video but you should build a couple saw horses and make a table so you’re not working on the ground like a meatball lol keep up the great video
Mark...while I know you might still be watching this....where did you get the resistor and I see you put it on the rectifier instead of the cap. I got a 200A rectifier and a 100,000uf cap. (go big or go home :-))) What terminals is it connected to? Can't tell from the vid. Have the parts but haven't started tearing into it yet. Waiting for the cap to arrive.
Heat shrink comes in red and black colors. Maybe put red shrink on (+) of the bridge dc output. And black shrink on ( - ) of the bridge dc output. Less confusing for another down the road. user. Question? How do you know if you have wired the output of the transformer in form: 'Polarized' A/C? AC Common and AC hot?
I saw this coming when he first told us he bought a 7$ 100amp rectifier .. So another example of 400$ of labor in order to save 10$ of rectifier. Otherwise a fantastic modification.
19:10 Time. Heat Sink. TRY to get an old Dell computer, the microprocessor, they use good large aluminum heatsinks - I used one, on my old Lincoln AC 225 amp machine to DC with a 300 amp bridge rectifier, and a home made choke, using microwave transformer secondary, wound with 4 turns of welding cord, and some aluminum heavy-duty high voltage capacitors. Works good, the fan inside the welder blows air over / through the welder case - staying cool !
Thanks for doing the leg work. At first it seemed like a lot of work for very little improvement but after watching you do it I think it would be pretty straight forward.
Though the metal on a brake rotor may look like nice shinny metal to weld on it's not. What happens when you're braking in fresh brakes is the pads are deposing a layer of brake material on the rotors. Trying weld through that material is asking for heartache... Also the rotor is cast Iron which is not weldable with standard flux core and it's pretty thick for such a light duty welder. If I were to weld that I'd grind the metal clean, then turn the amps up all the way and turn down the wire speed as much as possible to get as much heat as I could in the weld. Even still I'd expect poor results.
The welder fan motor, is 'air over motor' continous operation ac motor. For proper cooling it should be mounted for maximum airflow over it's own windings. Question? Would it be better to draw hot air out of the welder enclosure usuing a shrouded fan?
Would help if u slow down a bit, fix that stickout too far away from work piece, and try welding on something that is mild steel. Rotors are hardened if im not mistaken. Typically u need to preheat if its hardened with that lil thing. Like the AC to DCEN swap tho.
don't drag the stinger. move you're hand back and forth slowly, as u move into you're weld as you are laying the bead down. this will get you a very nice weld that gives a wave look to it and one solid weld run. .. good tip i offer. test it and you will improve your welds.
A single phase should work too, if it's amperage rating is high enough. I had a hard time finding a single phase rated high enough, and the first one I tried burned out in under a minute. The capacitor is a buffer that keeps feeding DC voltage when the AC reverses phase and creates a gap of no electricity being sent. It makes for a more constant DC voltage.
@@contact4mwy7 so I actually just finished doing that, I pit a 150A 1600v single phase in, and it seemed to provide a more consistent arc for me. I'm interested in the capacitor, but is that where I'd need to get into multiple phases? Or if not, where in the circut did you put it?
When we trained students we had them pad weld parallel beads at least four inches long. Do yourself a favor and use a couple of rolls of wire for that practice. You'll be pleased! Lincoln or Hobart wire welds better than budget wire which is often inconsistent (including Radnor wire from Airgas). Lincoln NR-211 is famous for good reason and trivially more expensive.
Good idea using the aluminum to dissipate the heat. How well does the bleed cap work hooked up to the rectifier (as opposed to directly to the capacitor)?
The bleed resister works just as well in either place as the wires are the same. It nulls the charge in about 10 to 15 seconds. If I touch the work piece before 15 seconds is up I will get a small spark. The aluminum works very well at pulling the heat away from the bridge rectifier. Thanks for watching!
Mark, it looks as if that 160 Ohm 10W resistor is connected between the positive and negative connection on the Bridge Rectifier? Is that correct? Very informative tutorial, Thanks.
MrWalterb123 yes, that's correct. It has a high enough resistance to not take away too much of the actual output, yet discharge the capacitor after each weld. This reduces the likelihood of getting those discharge sparks when touching the work piece between welds, or zapping the user by accident. It's a slow discharge, so it is possible to get a spark soon after welding, but after a few seconds that leftover charge should be gone thanks to that resistor. Thanks for asking.
Get rid of that copper gas type nozzel. Just take it off. It is causing you to hold your tip too far away from your work. You'll be amazed how much better it'll work.
I tried it without, like I have seen from other videos, and it touched the work piece and shorted out once. I thought that would shorten the life of the welder, so I put it back on. The copper nozzle is not energized and thus does not short out. I've seen some also use a replacement plastic nozzle, maybe I should look into that? I will make every effort to stay closer to the work piece. Thanks for the suggestion!
Flux core nozzles exist for good reason. (I use FCAW on my industrial machines when working outdoors.) Since I'm thrifty I just buy MIG nozzles and trim the end or slide it back (if Tweco style) to get proper wire stickout while not trashing my tip and diffuser.
Strange, my 125A machines "gas nozzle" is only 3/8" inside. I can run it fine with 1/2" stickout. HF sells extra tips for $8. I like the Nozzle. Sometimes I will do a bad scratch. Protects the orifice tip in dead stuck short.
I've used low hydrogen rods welding cast iron b4 I always wondered if flux core was similar because I repaired a cast wood stove back in 06 with my Hobart Handler 185 and it still holds I did a lot of prep and built a small fire b4 welding but it welded beautifully
Merlin is right ...cast iron is wrong testing material, also the plate was good idea but miss the "cream" to apply between the bridge and the plate helping with the dissipation.
Shot in the dark here. Maybe the voltage drops more than the stated 18vdc that the manufacturer states? This machine is a ac transformer type. I have owned one of these exact 125 amp machines for five years. The wire feed assembly is as* on these machines. Spend youd day removing the wire feed mechanism. Clean out the gunk grease they caked inside it and use a light weight, quality synthetic grease. On these boxes, it's all about consistent feed of your wire. Good luck.
These welders are like deceptive vacuum cleaner ads from the 1980's. Claimed peaj power of 12Amps. Yeah, peak current right before motor burns out. These welders will never get near 40amps. Find the video of the guy in certification school, welding 6 inch steel pipe with a Big 220v machine. He has it set at 90amps with correct 1/8 inch stick electrode.
If you wanna weld plate >1/4" wirh a 110v welder of any king preheat the metal with a torch before starting. I saw some long BB's and spatter, no real penetrating welds. Turn the feed speed up and use thinner wire for better heat transfer. I am not a professional, just a farm welder. I learned on and am happy with my 1965 AC buzzbox. It'll run 1/8" rods all day long.
Hello, Northern tools Klutch; multi process Inverter type. Dual input voltage, max thickness is 5/16." I would not even try past 1/8" on the Chicago Electric machine. I own one and it's pretty weak. I use preheat quite a lot. I went through 4lbs of wire, in practice just to get 1/2@$$ed competent with this box. Have sourced a 200A Single phase bridge. Tested the Diodes for function. Now just need to get nice bit of scrapyard aluminum. On tear down of my box I will make enough room to safely propane torch my connectors. Solder and plunge fit into 1/4" connector. A good fit is hermetically sealed. I prefer the 8mm machine screw bridge over the spade connector type.
dude all you needed was a large computer cpu heat sink but you need to run heat sink compound between the rectifier and your heat sink and all i've ever used is 0.35 wire in my HF 110v welder both before and especially after conversion because after converting the DC output is so much hotter, you also need to get away from using HF flux core wire, the stuff is crap. go to tractor supply and get a roll of Forney flux core or at least the lincoln wire from home depot and lastly learning how and when to control your stick out is more important then ever after converting to DC so you can weld both thin and think material.....
I edited the length of the welds in the video to make them shorter, as in they are not shown in actual real time. I have found going slower is key. Thanks.
Yes, Hi and Lo function as they should. I'm still using it mostly in this configuration, with the addition of a bigger aluminum heat sink for the rectifier.
I thought the convention was for the fan to be pushing air out from within the unit, not the other way round? Here's a tip that should improve the consistency of the wire feed. Disconnect the supply to the wire feed motor and install a separate, little 24v transformer. You see, as it is, the feed for this motor comes straight from the main transformer and this can mess up your welding. I got this tip from some other welder on UA-cam. They swear there is much improvement.
................one other thing, there is no such thing as "2 phase" electricity, there is single or 3 phase and if you're using 110/115/120 there's "single phase" only.
Cool mod but I would recommend more practice with stock welder before trying to trying to modify it as shown. that way you can see the difference in the welders performance both before and after... Strange garage has good channel with good vids on the HF 90amp model and what it can do.
Do not get the bridge rect that use spade connections. This is because you can stack ring connectors and use two or three 12AWG cables instead. Perhaps I see this because I have plenty of 12 AWG wire already. Also, why get three-phase? Wrong type altogether. May be the power rating is based on three-phase. You cannot just connect single phase to three phase.
I'm a guy that just got a welder 110 never known about welding or nothing like I said just a week ago I got one for the fun of it my weld would splatter a lot so I saw a video about is switching the polarities but it didn't require any of this stuff it works way better but my concern is is it right by the way I also said the same thing when I was about to try mine out after switching polarities making the gun negative and the clan positive about it blowing up
Some welders are wired cheaply and weld with an alternating current (AC) to the gun and clamp, while others, generally more expensive, weld with direct current (DC) to the gun and clamp meaning one is always positive and the other negative, and they are reversible depending on welding needs. My welder was AC from the factory, but I converted it to DC and made my clamp positive, gun negative.
@@ricardojuarez8803 it sounds to me that yours is already set to weld in DC current, you have a good machine there. I can say from experience, it takes practice. Lots of practice and experimenting with settings per the thickness of the metal you are working on.
Two things I learned about that welder one .change the ground clamp, it's a huge upgrade .two slow down you have to wait till you have a good pool before to move. I only did the ground clamp so far I have the stuff to do the conversation but I'm kind of happy with the welds I'm getting right now.when I get board I'll finish the mod. Ps. Take off you tip so you can get close.
I did take the tip off, but have to admit it permits the tip to come into contact with your work piece if you're not careful and THEN the Sparks fly! Lol. Thanks!
@@contact4mwy7 that's true,you havecto clean the tip in between welds but I find getting really close and dragging the puddle left and right has been working really good for me. That said I have one pound of experience. I dont know what I'm talking about but I feel that my welds were worthy of my motorcycle out of the box. It was hard for me to slow down that much but....
I am cheap. I added a piece of 1/2" copper to my ground clamp. A drilled & smashed flat plumbing coupling. Not going to pay $30 for a piece of brass from Thailand worth $4.
@@contact4mwy7 thanks a bunch! Anything else about the build that you find worked well or needed improvement? One thing I've done as well that was recommended by others was to add a beefier ground clamp to it. I replaced mine with a 500amp clamp, which is overkill but should help.
I added an aluminum plate to the back of the voltage rectifier to help with the heat from it. Works great at cooling the rectifier down. A rectangle of aluminum diamond plate could do the same, just mount the rectifier to the flat side. Aluminum conducts heat well.
When you burned out the rectifier at 13:56, you had some major sparks at your ground clamp. Why? Was it a bad connection? Could that be why the rectifier burned out? I also bought HF 90 amp unit. I have not yet used it. After doing this conversion, you say it burns a lot hotter and deeper. Will it still be possible to weld thin sheetmetal that's about 18 or 20 gauge?
Thanks for the questions, Ralph. I did not grind the clamp area enough, and there was an intermittent connection as a result. I do not know if that contributed to the failure of the 100 amp rectifier. It had become very hot under use. As for 18 or 20 gauge metal, hmmm, I have been using it to weld patch metal to a car and even on the lowest setting and slowest feed rate I am seeing a lot of "burn-through" holes, so, maybe it has made it stronger/more powerful in that regard? I recommend you try using it for what you intend "as-is" for now and decide if this conversion is necessary for your needs. As always, make sure the unit is UNPLUGGED whenever any of the covers are off.
you need to add a choke to the system, it controls the current,makes it smother.i used an old microwave transformer core, stripped & put about 5 or 6 rounds through it. makes a world of difference.cast iron is a pain also.
Thanks, Erwin. I guess I'll have to find a video on how to do that. Agreed that the rotor was not a good candidate for some weld testing. I'll be trying out some steel when it warms up here.
For all the carving and bending and frying you did, looks like a can of anti splatter might have been a better fix. Would the warranty still have been valid with this AC/DC change over?
I understand your suggestion of using a can of anti splatter to reduce the little bb's that are made. Changing the welder from AC to DC provides a kind of 'magnet' for the material being welded, and drives the electrons deeper into the metal. AC welding has a constant back and forth attraction, which means it pushes the metals together, then pulls them apart, over and over, 60 times a second. It is this 'repelling of the metal' that creates the bb's splatter.
For better heat transfer to the Aluminium plate the rectifier needs to be directly mounted on the plate with some thermal compound. I think you a have a metal strip in between the rectifier and the plate.
Good eye, Ahmed, yes there is a bit of the metal casing between the two, but it seems to transfer heat at a decent enough rate for now. Thanks for the info.
Nitpick alert ! Fractions are read as 35 thousandths , not " oh three five " . And yes , wrong kind of scrap - don't use cast iron . I like your spirit though . Yes , I know this is from 3 years ago .
No problems so far. Holding up well. I think the DC welds are better than the AC welds it made before converting it over. The real question is would I do it again? For sure!
Did your 150 amp do the trick? I have a 100 amp bridge and the feeder worked for about 5 seconds then quit out. I hear the relay clicking and a buzzing noise but no motor turn. Tested motor with 9v battery and it spun. Any help appreciated, thank you.
Same thing happened to me! It's not the motor, it's that your bridge rectifier has shorted out and that leaves no power to run the spool motor. My unit also buzzed and I heard the relay click, but did not feed wire. I measured the AC voltage at the bridge rectifier and it was down to like 1 volt AC. Surprisingly, this short did not burn out my transformer coil. Yes, 150 amp bridge rectifier is working great, but use a heat sink made of aluminum plate for better results.
Good luck, man! I have welded some with this new setup until I ran out of 0.035 wire. I will go back to 0.030 and stay with that from now on. The thicker wire is too much for the output of this welder in my opinion.
I have to ask, why in the world would you ever want to convert one of these to DCEN as that is a flux welder which are of course equally cheap. I just don't see the point aside from maybe it just being a technical challenge. From the standpoint of usability, practicality..I don't see any reason. if you want a cheap DC welder just spend the extra $80 and buy the HF 170 amp flux / MIG welder. It's a much better machine with more power. Lastly, the first thing you should have done was get a heavier duty brass ground clamp and slow down with your weld travel. That weld on the brake rotor was crap simply because you moved waaaay too fast. I think people start modding these without ever learning how to weld with the machine to begin with. I got great welds with the stock wire on my old 170amp simply because I took the time to really get to know the machine first.
Because, DCEN welds better and more consistently than AC electrode, this unit plugs into a 120 outlet which makes it more portable, cost savings, and we all gotta start somewhere.
You should better use 4 diode and you yourself build bridge rectifier each diode 300 amp 1000v on heatsink cooling by two fan one enter the air and the other as exhaust fan
He needs a little more practice at managing the weld puddle. Moving to fast, and his wire feed be be set too slow, or his wire feeder may be slipping. Anyway he can do a lot better than that.
Loosely translates to: is a three-phase rectifier ... 100 amp total ........ for each phase no more than 33 amp current. I believe this means that a three phase rectifier has the amperage spread out over the 3 inputs? This could be the reason that my 3 phase 100 amp bridge rectifier failed. The 150 amp rectifier is still functioning.
rtraduccion ok......estoy en lo mismo, medi los amperes en ca al conectar arco electrico y son 50 amperes ca, esposible que sean 50 amp x fase........pienso en conectar en paralelo todas las entradas...le enviare videos al respecto slds
After some research, the rectifier needs to be bigger and there for you might want a higher voltage cap. I'm fixin to mod my HF 125a and I'm going to go with a 300a, 1600V rectifier and a 100V, 24,00uf cap. I plan on doing a video of the mod but, don't anyone look for it too soon. Gotta wait for parts to be shipped in and delivered. Ac to DC is not the only mod I'm going to do.
Be sure to mount the capacitor with the + (positive) voltage going to ground. The - (negative wire goes to the welding cable.) It will blow up if backwards.
Would it be possible to get a diagram. I want to purchase one of these and convert it also I hear the feed motor needs to be rewired and also the main power wire and the ground clamp. Another question does this have an option for 240v
I wish I could attach an image to this reply, Sean, for a diagram. I had seen other videos on performing this change (Matt Heere's videos for the most part) and followed the wires back from the gun nozzle and from the clamp to know which wire was which. As for the feed motor, I have seen others have added a separate power supply and what not, but I have not seen a need to do that. Maybe because I am not what you would call a professional welder to notice the effect of sharing power between the feed motor and welding coil.
Mark Young - Outside The Box thanks I appreciate it. I'm not a professional by any means either actually I've only used a stick welder. I get by on the stick but need something to weld smaller material. Thanks again I'm sure I can figure it out your video is very helpful
Thanks Sean, and if you buy one, try it first "as is" where maybe as a stick welder you can control this welder in its AC output and still get good results. Changing this over to DC output for welding has resulted in less splatter bb's around the weld and maybe a bit more heat, but it's not night and day like I had expected.
Mark Young - Outside The Box thanks I definitely will although I believe I'm gonna hold off until I really have a need for one and get the more powerful one although I still intend to change it to D/C if I don't like the results. A friend of mine has a D/C one much more expensive tho out of my price range but I'm gonna borrow his to do the little job I need and also try and get the hang of it also. I appreciate your video and helpful tips I am subscribing to your channel because I like the fact your so helpful and videos are cool also. Thanks again
Mark Young - Outside The Box also I believe the issue you has with the space between the weld is because the wire motor does need its own power supply so you may want to give it a try it looks simple enough and should give you a consistent straight bead that looks professional. It looks like y out your doing a good job but feeder is causing some issues. Also maybe try some aluminum heat sink paste things I'm gonna try in a few weeks when I do purchase it and I am gonna lol
If I understand your question, I put the rectifier after the coil / before the welder clamp and gun. This way it converts the AC current coming from the coil into DC current which is fed to the gun and clamp. Clamp + / Gun -
Do you mean using the rectifier conversion to DC but without adding the capacitor to help smooth the DC pulses? If so, that might work with decent enough results, maybe?
Between the electrical outlet and the machine? I have my doubts for that as some of the electrical components are created to run internally on the AC power. By changing the whole unit to run on DC those components may not work or even be damaged.
Great vid! Boring watching every thing turn out perfect every time. I think that's why I like live music vs studio cuts. Now for some coaching. Being a welder in one of my earlier professions I've got some tips for you. As a righty I like to use a deer skin glove for the trigger hand n big heavy welder on my left use left hand on shaft to guide the tip. Slow down and your not going to get great penetration with that welder on a rotor. That's a thick chunk of Steel designed to get really hot. Just slow down keep one eye on your puddle and the other on where your going. Its my belief you'll achieve a lil better heat if you push vs pull with that size rig. All in all great video very entertaining. I have welded roll cages that have saved lives with that exact machine
Thanks Brent, and I really appreciate the tips! One difference is that this is flux core wire and most of the other videos I have seen about using it is "if it has slag, drag" but I know what you mean about the push method too. I still need a lot of practice with welding technique, for sure.
All good there. The lightbulb went off for me after watching this video on using flux core and technique. This guy looks to have it down to a T. ua-cam.com/video/VzDzW0seu3w/v-deo.html
I blew my welder rectifiers last year. Replaced them with 4 x Full bridge 50Amps in parallel. Since then The welder got many harsh abuses and still running Ok. 50Amps Bridges are pretty inexpensive from China and the job OK.
Jim Viau you hooked these 4 up in parallel to the same outputs? As shown in this video, my single 100 watt unit burned out fairly quickly. 150 one still going strong.
Blew my 3-Phase Diode Bridge Rectifier 150A 1200V SQL150A today while welding. Ordered 2 150A 1600v Bridge Rectifiers. Did not have any additional heat sink. Will have to try the parallel route with these and add a heat sink.
@@oldguy59 before the garage I have now, I was changing car parts in the driveway, in the snow. Being on a cement floor is way better to me, and I don't have a work bench (yet).
I believe the welds can only get good to a certain point and then the limitations of being AC prevent them from being a truly good weld. The low amperage doesn't help much either. These welders are handy for small jobs and inexpensive, but really, spend the money on a better unit? There are many webpages explaining that Flux Core Wire should only be run DC with the gun Negative to keep the Flux slag from being drawn into the weld.
Before the modification this was an AC welder which has no polarity. After the DC modification, the polarity is positive clamp, electrode negative, which pulls the metal and arc into the work piece, and should produce less splatter. At least, that is the theory?
Looking back, that probably was the way to go. As someone with no welding experience will often do, I was looking for something cheap to start with and see how it goes. I also like the fact that this one can plug into any 110 outlet.
Can you put a parts list on here for me
Items bought through Ebay: ONE Large capacitor with values of Mallory CGS Series 21000uF - 100VDC . ONE resistor with value of 160 Ohm 10W 1% Resistor Silicone Wirewound. ONE Bridge Rectifier of MDQ 150A Single-Phase Diode Bridge Rectifier. Items bought elsewhere: 6 feet of 6 gauge wire (not much to spare, so 7 feet of wire might be better). I used FOUR 1/4 inch copper connector tubes to join wires together with solder. TWO packages of 6 gauge wire terminals for connections to the bridge rectifier and the large capacitor terminals. Various sized nuts, bolts and washers to mount the bridge rectifier and to use on the connection terminals.
Where did you buy the capacitor from?
I found it searching on Ebay.
Mark Young - Outside The Box what are the specs on it? Great video.
Thanks! This is a Mallory CGS Series 21000uF - 100VDC. I measured the DC voltage coming from the welder on its high output setting and it was less than 30 volts DC, so using a capacitor rated for up to 100 volts DC "should" be ok.
I've just got to say that I've owned a HF Flux125 for about a year now, and that I have taken some professional welding courses at a local trade school, and I have no problem with the machine, my weld performance , overall strength and "eye" appeal. I can certainly attest that when I 've used superior shop machines in the DCEN mode, that the weld quality is better, no doubt. The videos I am seeing on YT who are doing DC conversions, can't seem to run a decent weld to begin with. So before all you Flux125 owners think you need to convert to get a decent weld, consider practicing a constant 1/2" "stick out", 5 - 10 degree drag angle, correct wire feed speed and voltage setting (hi -lo). I had to tweak settings for different steel thicknesses. I had to play with wire feeder tension. I make sure my base metals are well prepped and fitted up. All these factors can make a big difference in weld quality. The main modification that I think would be quite helpful, would be to swap out the ground clamp to a bronze unit that HF sells. I just haven't yet on my machine, because it welds quite nicely for me. Oh and I use Lincoln NR-211-MP .035"wire.
Thank you for saying all of that, Sam, it's very true. I started using 0.035 wire too.
Thank you. I just stumbled on a few of these videos and was like "oh shit do I need to risk melting something down messing with wires to make my little cheap welder work better?" 🤣🤣
I've welded three times, made a couple little burn pits. Seems to be fine I know I know nothing so it'll get there.
Oh wow.....really impressed with you starting out feeding your ego with your welding courses bragging....lol.
The fact of the matter is some of us can weld AND a DC fluxcore welder will always outperform a cheaper AC output one regardless of how well
you think you can weld.
So puff your chicken chest out some more and tell us seasoned welders how you can weld now after taking your little welding night classes....lol.
Some of us have been welding since we could walk and have many, many hours under our belts and we are not ragging on less experienced
welders.....unlike YOU. You and your overinflated ego can go kick rocks as far as I am concerned.
Anyone wanting to upgrade their AC output flux core welder to a DC output will only improve their welders doing so.....that is the whole reason
behind this video.
I always laugh because regardless of the video or subject there is ALWAYS at least one egotistical A hole in the comments section....ha ha ha ha ha ha!
Right. It’s not the machine it’s the user.
My welds with the 90 amp look great no conversion slow down and watch puddle boss.
You have illustrated "Third one is the charm". Since you did not convert three welders you did not get the perfect conversion but you combined what works with what not to do with enthusiasm and a good voice. Good luck with future videos.
Thank you Stuart! I know it was a bit of a hot mess, but the end result, with the additional aluminum heat sink, is still working just fine, even with 0.035 gauge wire.
Cool vid, but you need to get into a welding class. I think that would do you more good than changing to DC.
Thank you!
Agreed, I own a similar welder, and have used it to so a lot of welds for friends and stuff, and I have gotten a ton better. I can lay dimes on these cheap AC machines, and now I just bought my first TIG welder. You can tell he is a new welder lol, but with practice comes experience.
Loved the video. You showed mistakes, lessons learned, and adjustments. There are more professionally edited videos out there but they only show the perfect parts. You have a good attitude and I am sure you are welding has greatly improved.
Thank you, Ken! There have been some improvements since this video was made, in my welding, thanks also to comments here offering tips.
For a heat sink to work at all it has to be in direct contact with the metal it’s wicking heat away from. Get that sheet metal out of between the rectifier and the aluminum sheet and apply a little heat sink compound and use a small cheap fan to blow more air over the outside of that plate since it’s your heatsink and surface area is so low without fins you’ll need to pass more air over it so a small table fan or clip on fan on high should do it. Low duty cycle that way too. Look up how to replace a heat sink on sun v120 servers. Simple and use same principles thermal conductive paste and tension against the metal of the rectifier and the “heatsink”.
I used that same brand rectifier, got the 200amp, it works great! It's a bit slower to strike, but once bead starts the weld lays down and penetrates base metal much better. Also after welding for ten minutes straight, the rectifier wasn't even hot!
got my welder today and i didnt do mods other than to practiced and my weld are flawless dont need to convert to dc when the welder works perfectly fine
Those discs may chatter a bit, when you put them back on. Should have used a piece of scrap for the demo.
that's why we all used the 150 amp BR to begin with, at 100 amps there isn't enough head room for the peak amperage. also the reason your AC welds had so much splatter is because you had the wire speed up too high, were moving too fast and had too much stick out. As long as you know how to weld the HF 115v flux core welder is perfectly capable of running a consistent bead in AC form, the main reason for the DCEN conversion is weld penetration . the conversion creates another problem which you didn't address, because of the hotter arc higher current flow with DC, it caused the current for the wire feed motor to sag which in turn causes the wire speed to pulse up and down. AS for your welding in general you need to slow your wire speeds down, start a puddle and move the puddle along as you weld and keep your stick out down to a half inch unless your are welding really thin metal....
I went with 200amp/1600 volts.
Welding cast iron instead of steel may be part of the problem with the welds.
I have converted my older style HF 90 amp welder, and I was able to fit all my parts inside. I moved the transformer over about 1/2" to the right, and rotated the wire feed control board to the top. I installed a transformer for wire feed and I also installed a ground dinse socket and plug, moved the power cord to the rear and installed an adapter block for a Miller m10 mig gun. I also installed a higher volume fan with the heat sink on an angle on the left side in front of that fan. I'm hoping to finish wiring the rectifier in the next few days, and give it a try. I will have to power this with a generator since my shop is on an Amish farm with no electric.
Bryant, that's an amazing setup you have going, and from an Amish farm! Much respect to you!
You would get better heat rejection from the rectifier if you attached it directly to the aluminum plate(alongside the center section you have it attached to in the video.) I would suggest using some 'heat sink paste', just a dab, to improve conduction.
As it is, the only connection is through the 'strip' down the middle, leaving 80%of the heat sink area floating in the breeze,touching nothing. The Al will conduct so well it does not have to be centered in the slab, and you will get so much more conduction area it would not make any difference anyway, so set it to one side or the other.
I have an off-brand, and plan to do a similar mod. I bought the same rectifier, and then bought the second one you have before doing anything. The second one was not available from ebay or amaz, so I went to aliexpress. I have to figure out where to put it in this unit which is not layed out the same. I'll get there.
More good info. Thanks.
Thanks for making this video. I have to say, there is more to welding then putting the tip down, squeezing the trigger and moving the gun. This is an older video so maybe you have had a chance to practice a little. You’re after the mod weld should have been a fairly good bead.
A great video, thank you for posting, I'm sure brake discs are cast iron, you could probably get better results from welding some angle iron? I'm thinking of doing this mod to my old SIP arc welder.
Another part to this project, is adding another small 24volt transformer, to independently run the drive motor, to avoid voltage drop.
Metal Guitar FailArmy,
That is "Zero Labs" hack on UA-cam for these welders.
I used a 20v transformer which peaks out at about 23 or so, so it runs it well. Interestingly, I tried a 24vdc power supply, but the range of control was not much.
I like your video but you should build a couple saw horses and make a table so you’re not working on the ground like a meatball lol keep up the great video
Love the disclaimer. :-) "Don't blame me if you screw this up."
Mark...while I know you might still be watching this....where did you get the resistor and I see you put it on the rectifier instead of the cap. I got a 200A rectifier and a 100,000uf cap. (go big or go home :-))) What terminals is it connected to? Can't tell from the vid. Have the parts but haven't started tearing into it yet. Waiting for the cap to arrive.
Heat shrink comes in red and black colors.
Maybe put red shrink on (+) of the bridge dc output.
And black shrink on ( - ) of the bridge dc output.
Less confusing for another down the road.
user.
Question? How do you know if you have wired the output of the transformer in form: 'Polarized' A/C?
AC Common and AC hot?
I saw this coming when he first told us he bought a 7$ 100amp rectifier .. So another example of 400$ of labor in order to save 10$ of rectifier. Otherwise a fantastic modification.
19:10 Time. Heat Sink. TRY to get an old Dell computer, the microprocessor, they use good large aluminum heatsinks - I used one, on my old Lincoln AC 225 amp machine to DC with a 300 amp bridge rectifier, and a home made choke, using microwave transformer secondary, wound with 4 turns of welding cord, and some aluminum heavy-duty high voltage capacitors. Works good, the fan inside the welder blows air over / through the welder case - staying cool !
I loved this you don't give up!!! Never give up dude! With practice that flux core welder will work keep trying it'll come
Thanks Dan, I bought a different hood that has adjustable shade so I can actually see what I am doing now. Still practicing!
Thanks for doing the leg work. At first it seemed like a lot of work for very little improvement but after watching you do it I think it would be pretty straight forward.
It was a lot of work for the return, but it did improve the welder overall. Still going strong today.
Though the metal on a brake rotor may look like nice shinny metal to weld on it's not. What happens when you're braking in fresh brakes is the pads are deposing a layer of brake material on the rotors. Trying weld through that material is asking for heartache... Also the rotor is cast Iron which is not weldable with standard flux core and it's pretty thick for such a light duty welder. If I were to weld that I'd grind the metal clean, then turn the amps up all the way and turn down the wire speed as much as possible to get as much heat as I could in the weld. Even still I'd expect poor results.
The welder fan motor, is 'air over motor' continous operation ac motor. For proper cooling it should be mounted for maximum airflow over it's own windings. Question? Would it be better to draw hot air out of the welder enclosure usuing a shrouded fan?
would like to see it weld on a piece of steel not cast iron that most rotors are made of. your conversion looks like it worked.
Would help if u slow down a bit, fix that stickout too far away from work piece, and try welding on something that is mild steel. Rotors are hardened if im not mistaken. Typically u need to preheat if its hardened with that lil thing. Like the AC to DCEN swap tho.
Thank you for your advice, Benjamin!
don't drag the stinger. move you're hand back and forth slowly, as u move into you're weld as you are laying the bead down. this will get you a very nice weld that gives a wave look to it and one solid weld run. .. good tip i offer. test it and you will improve your welds.
Why do you need the capacitor and the 3ph rectifier? Why not just a single phase rectifier after all board but before the leads leave the unit?
A single phase should work too, if it's amperage rating is high enough. I had a hard time finding a single phase rated high enough, and the first one I tried burned out in under a minute. The capacitor is a buffer that keeps feeding DC voltage when the AC reverses phase and creates a gap of no electricity being sent. It makes for a more constant DC voltage.
@@contact4mwy7 so I actually just finished doing that, I pit a 150A 1600v single phase in, and it seemed to provide a more consistent arc for me. I'm interested in the capacitor, but is that where I'd need to get into multiple phases? Or if not, where in the circut did you put it?
@calebtomes121 the capacitor goes across the DC leads coming from the rectifier, positive to positive, negative to negative.
@contact4mwy7 thanks, why did you decide on 21000mfd? Just trying to gauge what I need and why
@@calebtomes121 that's the measurement of how much of a charge the capacitor can hold.
you got a lot of wires going through some holes with rough edges. some grommets may be in order.
BRILLIANT !
If its dc the probes cant be too much long it cause lost on current on the wire and not in electrode dc is great but with alot losses
When we trained students we had them pad weld parallel beads at least four inches long. Do yourself a favor and use a couple of rolls of wire for that practice. You'll be pleased! Lincoln or Hobart wire welds better than budget wire which is often inconsistent (including Radnor wire from Airgas). Lincoln NR-211 is famous for good reason and trivially more expensive.
Ob Fuscated thanks for the tips. I am finding that practice helps a lot.
Do yourself a BIG favor and spring for 6 Ga. Tee Bolt wire connectors. Fast, easy anmd maximum conductivity.
Good idea using the aluminum to dissipate the heat. How well does the bleed cap work hooked up to the rectifier (as opposed to directly to the capacitor)?
The bleed resister works just as well in either place as the wires are the same. It nulls the charge in about 10 to 15 seconds. If I touch the work piece before 15 seconds is up I will get a small spark. The aluminum works very well at pulling the heat away from the bridge rectifier. Thanks for watching!
If you are going to cut the gun wire anyhow . Why mess with the 2 terminal wires on the board and risk damage .???
Mark, it looks as if that 160 Ohm 10W resistor is connected between the positive and negative connection on the Bridge Rectifier? Is that correct? Very informative tutorial, Thanks.
MrWalterb123 yes, that's correct. It has a high enough resistance to not take away too much of the actual output, yet discharge the capacitor after each weld. This reduces the likelihood of getting those discharge sparks when touching the work piece between welds, or zapping the user by accident. It's a slow discharge, so it is possible to get a spark soon after welding, but after a few seconds that leftover charge should be gone thanks to that resistor. Thanks for asking.
This was done to drain the capacitor's stored energy down. This is typically used on high current power supplies.
Perhaps because the brake rotor is cast iron which is difficult to weld your results are less than desired. Try it on some plate steel.
Get rid of that copper gas type nozzel. Just take it off. It is causing you to hold your tip too far away from your work. You'll be amazed how much better it'll work.
I tried it without, like I have seen from other videos, and it touched the work piece and shorted out once. I thought that would shorten the life of the welder, so I put it back on. The copper nozzle is not energized and thus does not short out. I've seen some also use a replacement plastic nozzle, maybe I should look into that? I will make every effort to stay closer to the work piece. Thanks for the suggestion!
plastic nozzle and trim wire to 1/4 inch stay on puddle longer.
Thanks Gary, I will give it a try.
Flux core nozzles exist for good reason. (I use FCAW on my industrial machines when working outdoors.) Since I'm thrifty I just buy MIG nozzles and trim the end or slide it back (if Tweco style) to get proper wire stickout while not trashing my tip and diffuser.
Strange, my 125A machines "gas nozzle" is only 3/8" inside. I can run it fine with 1/2" stickout. HF sells extra tips for $8. I like the Nozzle. Sometimes I will do a bad scratch.
Protects the orifice tip in dead stuck short.
Cast iron is the last thing you should be "testing on",
I've used low hydrogen rods welding cast iron b4 I always wondered if flux core was similar because I repaired a cast wood stove back in 06 with my Hobart Handler 185 and it still holds I did a lot of prep and built a small fire b4 welding but it welded beautifully
Your wire speed is to high
Merlin is right ...cast iron is wrong testing material, also the plate was good idea but miss the "cream" to apply between the bridge and the plate helping with the dissipation.
Shot in the dark here.
Maybe the voltage drops more than the stated 18vdc that the manufacturer states?
This machine is a ac transformer type.
I have owned one of these exact 125 amp machines for five years. The wire feed assembly is as* on these machines.
Spend youd day removing the wire feed mechanism. Clean out the gunk grease they caked inside it and use a light weight, quality synthetic grease.
On these boxes, it's all about consistent feed of your wire. Good luck.
These welders are like deceptive vacuum cleaner ads from the 1980's. Claimed peaj power of 12Amps. Yeah, peak current right before motor burns out.
These welders will never get near 40amps.
Find the video of the guy in certification school, welding 6 inch steel pipe with a Big 220v machine. He has it set at 90amps with correct 1/8 inch stick electrode.
If you wanna weld plate >1/4" wirh a 110v welder of any king preheat the metal with a torch before starting. I saw some long BB's and spatter, no real penetrating welds. Turn the feed speed up and use thinner wire for better heat transfer. I am not a professional, just a farm welder. I learned on and am happy with my 1965 AC buzzbox. It'll run 1/8" rods all day long.
Thank you, all good points for me and others interested in doing this!
Hello, Northern tools Klutch; multi process Inverter type. Dual input voltage, max thickness is 5/16."
I would not even try past 1/8" on the Chicago Electric machine. I own one and it's pretty weak. I use preheat quite a lot.
I went through 4lbs of wire, in practice just to get 1/2@$$ed competent with this box.
Have sourced a 200A Single phase bridge.
Tested the Diodes for function. Now just need to get nice bit of scrapyard aluminum.
On tear down of my box I will make enough room to safely propane torch my connectors. Solder and plunge fit into 1/4" connector. A good fit is hermetically sealed.
I prefer the 8mm machine screw bridge over the spade connector type.
dude all you needed was a large computer cpu heat sink but you need to run heat sink compound between the rectifier and your heat sink and all i've ever used is 0.35 wire in my HF 110v welder both before and especially after conversion because after converting the DC output is so much hotter, you also need to get away from using HF flux core wire, the stuff is crap. go to tractor supply and get a roll of Forney flux core or at least the lincoln wire from home depot and lastly learning how and when to control your stick out is more important then ever after converting to DC so you can weld both thin and think material.....
All good advice, especially about using a CPU computer aluminum heat sink. Thanks.
I have never had a problem with the welds that the 90 amp welder produced or the HF flux-core wire, it is user malfunction.
It's actually better to use multiple small compasitors then one or two big compacitors. Try 6 to 8 small ones. Big difference.
Skip the rectifier and spend some time learning welding and that will help you weld better than switching to DC.
FUUUULL Bridge Rectifaiarrrr :D
You are going way to fast with your welds...
Go slower, will im prove things alot
I edited the length of the welds in the video to make them shorter, as in they are not shown in actual real time. I have found going slower is key. Thanks.
but ur weld looks like u going to fast ,slow down a little u will see huge deference
i do like ur mods
thinking about doing this to my welder but i'm curious if the hi and low settings still work
Yes, Hi and Lo function as they should. I'm still using it mostly in this configuration, with the addition of a bigger aluminum heat sink for the rectifier.
I thought the convention was for the fan to be pushing air out from within the unit, not the other way round?
Here's a tip that should improve the consistency of the wire feed. Disconnect the supply to the wire feed motor and install a separate, little 24v transformer. You see, as it is, the feed for this motor comes straight from the main transformer and this can mess up your welding. I got this tip from some other welder on UA-cam. They swear there is much improvement.
................one other thing, there is no such thing as "2 phase" electricity, there is single or 3 phase and if you're using 110/115/120 there's "single phase" only.
But 2 phase sounds cooler.
@@contact4mwy7 Touche' !
Great video frm kenya.
Hello Kenya! Thank you!
You need to upgrade that crappy stock ground clamp to a quality one. When I did this to mine it made a big difference.
Ok, thank you.
Less stick out,about 3/16 of a inch,slow down the speed,and you are golden,gr8 video to
Thank you, I appreciate that!
Cool mod but I would recommend more practice with stock welder before trying to trying to modify it as shown. that way you can see the difference in the welders performance both before and after... Strange garage has good channel with good vids on the HF 90amp model and what it can do.
Do not get the bridge rect that use spade connections. This is because you can stack ring connectors and use two or three 12AWG cables instead. Perhaps I see this because I have plenty of 12 AWG wire already. Also, why get three-phase? Wrong type altogether. May be the power rating is based on three-phase. You cannot just connect single phase to three phase.
I'm a guy that just got a welder 110 never known about welding or nothing like I said just a week ago I got one for the fun of it my weld would splatter a lot so I saw a video about is switching the polarities but it didn't require any of this stuff it works way better but my concern is is it right by the way I also said the same thing when I was about to try mine out after switching polarities making the gun negative and the clan positive about it blowing up
Some welders are wired cheaply and weld with an alternating current (AC) to the gun and clamp, while others, generally more expensive, weld with direct current (DC) to the gun and clamp meaning one is always positive and the other negative, and they are reversible depending on welding needs. My welder was AC from the factory, but I converted it to DC and made my clamp positive, gun negative.
tanks mine in the inside says i can just swapp em like i had n yes depending wire use tanks
@@ricardojuarez8803 it sounds to me that yours is already set to weld in DC current, you have a good machine there. I can say from experience, it takes practice. Lots of practice and experimenting with settings per the thickness of the metal you are working on.
Hi I hqve a question after converting to DC can use for weld Aluminum welding
Babu Mistry I do not have an answer for you on welding aluminum, but maybe someone reading the comments can?
Two things I learned about that welder one .change the ground clamp, it's a huge upgrade .two slow down you have to wait till you have a good pool before to move. I only did the ground clamp so far I have the stuff to do the conversation but I'm kind of happy with the welds I'm getting right now.when I get board I'll finish the mod. Ps. Take off you tip so you can get close.
I did take the tip off, but have to admit it permits the tip to come into contact with your work piece if you're not careful and THEN the Sparks fly! Lol. Thanks!
@@contact4mwy7 that's true,you havecto clean the tip in between welds but I find getting really close and dragging the puddle left and right has been working really good for me. That said I have one pound of experience. I dont know what I'm talking about but I feel that my welds were worthy of my motorcycle out of the box. It was hard for me to slow down that much but....
I am cheap. I added a piece of 1/2" copper to my ground clamp. A drilled & smashed flat plumbing coupling. Not going to pay $30 for a piece of brass from Thailand worth $4.
@@ayebee1207 that's cool. I think I only gave like 12$ for mine and it was twice what it came with but yeah do it for free .its always better.
Thanks for the video! I was wondering if the 6 gauge wire held up for you long term? That's what I have as well.
I'm still using it, heavy at times, and have had no issues with that size wire.
@@contact4mwy7 thanks a bunch! Anything else about the build that you find worked well or needed improvement?
One thing I've done as well that was recommended by others was to add a beefier ground clamp to it. I replaced mine with a 500amp clamp, which is overkill but should help.
I added an aluminum plate to the back of the voltage rectifier to help with the heat from it. Works great at cooling the rectifier down. A rectangle of aluminum diamond plate could do the same, just mount the rectifier to the flat side. Aluminum conducts heat well.
its amazing how people dont have a work table. i live in a 1 bedroom apartment i have a work table.
try welding steel next time, that rotor looked to be cast iron
When you burned out the rectifier at 13:56, you had some major sparks at your ground clamp. Why? Was it a bad connection? Could that be why the rectifier burned out?
I also bought HF 90 amp unit. I have not yet used it.
After doing this conversion, you say it burns a lot hotter and deeper. Will it still be possible to weld thin sheetmetal that's about 18 or 20 gauge?
Thanks for the questions, Ralph. I did not grind the clamp area enough, and there was an intermittent connection as a result. I do not know if that contributed to the failure of the 100 amp rectifier. It had become very hot under use. As for 18 or 20 gauge metal, hmmm, I have been using it to weld patch metal to a car and even on the lowest setting and slowest feed rate I am seeing a lot of "burn-through" holes, so, maybe it has made it stronger/more powerful in that regard? I recommend you try using it for what you intend "as-is" for now and decide if this conversion is necessary for your needs. As always, make sure the unit is UNPLUGGED whenever any of the covers are off.
@@contact4mwy7
Thank you. I'll hold off and get accustomed to the factory unit before I do any modifications.
@@RalphSampson... Good, and there a lot of comments on here about how to get started and make improvements as you go!
Pp do you have a list or something that I can use to compare dry put some of the parts I might still some of my old
Yes, list is in comments.
you need to add a choke to the system, it controls the current,makes it smother.i used an old microwave transformer core, stripped & put about 5 or 6 rounds through it. makes a world of difference.cast iron is a pain also.
Thanks, Erwin. I guess I'll have to find a video on how to do that. Agreed that the rotor was not a good candidate for some weld testing. I'll be trying out some steel when it warms up here.
For all the carving and bending and frying you did, looks like a can of anti splatter might have been a better fix. Would the warranty still have been valid with this AC/DC change over?
capacitor discharge no inductor chocke and no gaz ay think there.
I understand your suggestion of using a can of anti splatter to reduce the little bb's that are made. Changing the welder from AC to DC provides a kind of 'magnet' for the material being welded, and drives the electrons deeper into the metal. AC welding has a constant back and forth attraction, which means it pushes the metals together, then pulls them apart, over and over, 60 times a second. It is this 'repelling of the metal' that creates the bb's splatter.
For better heat transfer to the Aluminium plate the rectifier needs to be directly mounted on the plate with some thermal compound. I think you a have a metal strip in between the rectifier and the plate.
Good eye, Ahmed, yes there is a bit of the metal casing between the two, but it seems to transfer heat at a decent enough rate for now. Thanks for the info.
Nitpick alert ! Fractions are read as 35 thousandths , not " oh three five " . And yes , wrong kind of scrap - don't use cast iron . I like your spirit though . Yes , I know this is from 3 years ago .
Good luck buddy
Check out the channel "Welding Tips and Tricks." He has some of the best advise to being a better welder...Good Luck.
Thanks, Stephen, will do!
Stephen Festus agree
Cool project, I may have to try it! Now that this video's a year old, how's it holding up... have you had any problems? Thanks!
No problems so far. Holding up well. I think the DC welds are better than the AC welds it made before converting it over. The real question is would I do it again? For sure!
"good melting going on..."
I like... peace
I don't think the machine is set properly that why you have those welds on AC current
Too much angle too fast a bead. Head spacer 3/8 to 1/2 inch max. Use mild flat or angle iron. Good effort to show difference.
I was wondering do you need to change to a different wire when you change polarity? Just curious
You don't have to. I've been using both 0.030 and 0.035 flux core wire.
I haven't EVER seen any innershield flux-core wire that runs AC
@@slick1rick1 HF sells 10,000,000. 90A and 125A machines a year with a pound of wire in them.
Did your 150 amp do the trick? I have a 100 amp bridge and the feeder worked for about 5 seconds then quit out. I hear the relay clicking and a buzzing noise but no motor turn. Tested motor with 9v battery and it spun. Any help appreciated, thank you.
Same thing happened to me! It's not the motor, it's that your bridge rectifier has shorted out and that leaves no power to run the spool motor. My unit also buzzed and I heard the relay click, but did not feed wire. I measured the AC voltage at the bridge rectifier and it was down to like 1 volt AC. Surprisingly, this short did not burn out my transformer coil. Yes, 150 amp bridge rectifier is working great, but use a heat sink made of aluminum plate for better results.
Mark Young - Outside The Box awsome thank you so much. Will defiantly use the heat sink. Great video by the way ,take care -john
Good luck, man! I have welded some with this new setup until I ran out of 0.035 wire. I will go back to 0.030 and stay with that from now on. The thicker wire is too much for the output of this welder in my opinion.
that disc brake is not what you want to be welding with that, DC or AC. I hope you have replaced that clamp by now.
Thanks, Richard, I know that now. I'm new. I have not replaced the clamp yet. Thanks for commenting.
Buy a miller, lincoln on craigslist for 150-300$ and call it a day. Its not worth putting money into something cheap as it is.
I have to ask, why in the world would you ever want to convert one of these to DCEN as that is a flux welder which are of course equally cheap. I just don't see the point aside from maybe it just being a technical challenge. From the standpoint of usability, practicality..I don't see any reason. if you want a cheap DC welder just spend the extra $80 and buy the HF 170 amp flux / MIG welder. It's a much better machine with more power. Lastly, the first thing you should have done was get a heavier duty brass ground clamp and slow down with your weld travel. That weld on the brake rotor was crap simply because you moved waaaay too fast. I think people start modding these without ever learning how to weld with the machine to begin with. I got great welds with the stock wire on my old 170amp simply because I took the time to really get to know the machine first.
Because, DCEN welds better and more consistently than AC electrode, this unit plugs into a 120 outlet which makes it more portable, cost savings, and we all gotta start somewhere.
Probably welds find just your puddle manipulation is kinda erractic
Thank you for the advice. I'm new at trying this out, but getting better thanks to suggestions.
ua-cam.com/video/KzSNpsLT40Q/v-deo.html
You should better use 4 diode and you yourself build bridge rectifier each diode 300 amp 1000v on heatsink cooling by two fan one enter the air and the other as exhaust fan
It's hard to dissipate heat from diodes. These full wave diodes work well and are a relatively small package designed for a heat sink.
He needs a little more practice at managing the weld puddle. Moving to fast, and his wire feed be be set too slow, or his wire feeder may be slipping. Anyway he can do a lot better than that.
es un rectificador trifasico...de 100 amp total........por cada fase no mas de 33 amp de corriente
Loosely translates to: is a three-phase rectifier ... 100 amp total ........ for each phase no more than 33 amp current. I believe this means that a three phase rectifier has the amperage spread out over the 3 inputs? This could be the reason that my 3 phase 100 amp bridge rectifier failed. The 150 amp rectifier is still functioning.
rtraduccion ok......estoy en lo mismo, medi los amperes en ca al conectar arco electrico y son 50 amperes ca, esposible que sean 50 amp x fase........pienso en conectar en paralelo todas las entradas...le enviare videos al respecto slds
Arte dex et schice ornigo. Taku'te bereto.
Drocnas pemitre val groz. Echteu¿
Hmmm...HF is discontinuing the 90 amp model welder. Would these same parts work to convert the new 125 amp flux welder.
That's a good question, The Rev..... I wonder too!
After some research, the rectifier needs to be bigger and there for you might want a higher voltage cap. I'm fixin to mod my HF 125a and I'm going to go with a 300a, 1600V rectifier and a 100V, 24,00uf cap. I plan on doing a video of the mod but, don't anyone look for it too soon. Gotta wait for parts to be shipped in and delivered. Ac to DC is not the only mod I'm going to do.
Be sure to mount the capacitor with the + (positive) voltage going to ground. The - (negative wire goes to the welding cable.) It will blow up if backwards.
Would it be possible to get a diagram. I want to purchase one of these and convert it also I hear the feed motor needs to be rewired and also the main power wire and the ground clamp. Another question does this have an option for 240v
I wish I could attach an image to this reply, Sean, for a diagram. I had seen other videos on performing this change (Matt Heere's videos for the most part) and followed the wires back from the gun nozzle and from the clamp to know which wire was which. As for the feed motor, I have seen others have added a separate power supply and what not, but I have not seen a need to do that. Maybe because I am not what you would call a professional welder to notice the effect of sharing power between the feed motor and welding coil.
Mark Young - Outside The Box thanks I appreciate it. I'm not a professional by any means either actually I've only used a stick welder. I get by on the stick but need something to weld smaller material. Thanks again I'm sure I can figure it out your video is very helpful
Thanks Sean, and if you buy one, try it first "as is" where maybe as a stick welder you can control this welder in its AC output and still get good results. Changing this over to DC output for welding has resulted in less splatter bb's around the weld and maybe a bit more heat, but it's not night and day like I had expected.
Mark Young - Outside The Box thanks I definitely will although I believe I'm gonna hold off until I really have a need for one and get the more powerful one although I still intend to change it to D/C if I don't like the results. A friend of mine has a D/C one much more expensive tho out of my price range but I'm gonna borrow his to do the little job I need and also try and get the hang of it also. I appreciate your video and helpful tips I am subscribing to your channel because I like the fact your so helpful and videos are cool also. Thanks again
Mark Young - Outside The Box also I believe the issue you has with the space between the weld is because the wire motor does need its own power supply so you may want to give it a try it looks simple enough and should give you a consistent straight bead that looks professional. It looks like y out your doing a good job but feeder is causing some issues. Also maybe try some aluminum heat sink paste things I'm gonna try in a few weeks when I do purchase it and I am gonna lol
Can full bridge rectifier be putted before welder - after grid?
If I understand your question, I put the rectifier after the coil / before the welder clamp and gun. This way it converts the AC current coming from the coil into DC current which is fed to the gun and clamp. Clamp + / Gun -
No, i meant to feed welder just with pulsing DC (rectifier AC)...i see many people puting diode bridge between welder and clamps.
Do you mean using the rectifier conversion to DC but without adding the capacitor to help smooth the DC pulses? If so, that might work with decent enough results, maybe?
@@contact4mwy7 yes, but between grid network ac to welder with smaller and cheaper full bridge rectifier.
Between the electrical outlet and the machine? I have my doubts for that as some of the electrical components are created to run internally on the AC power. By changing the whole unit to run on DC those components may not work or even be damaged.
You get full rectify with this?
If you are asking if I got DC output, yes. Thanks for asking.
Great vid! Boring watching every thing turn out perfect every time. I think that's why I like live music vs studio cuts. Now for some coaching. Being a welder in one of my earlier professions I've got some tips for you. As a righty I like to use a deer skin glove for the trigger hand n big heavy welder on my left use left hand on shaft to guide the tip. Slow down and your not going to get great penetration with that welder on a rotor. That's a thick chunk of Steel designed to get really hot. Just slow down keep one eye on your puddle and the other on where your going. Its my belief you'll achieve a lil better heat if you push vs pull with that size rig. All in all great video very entertaining. I have welded roll cages that have saved lives with that exact machine
Thanks Brent, and I really appreciate the tips! One difference is that this is flux core wire and most of the other videos I have seen about using it is "if it has slag, drag" but I know what you mean about the push method too. I still need a lot of practice with welding technique, for sure.
Mark Young - Outside The Box oh yea forgot you said fluxcore
All good there. The lightbulb went off for me after watching this video on using flux core and technique. This guy looks to have it down to a T. ua-cam.com/video/VzDzW0seu3w/v-deo.html
Working for 125amp???
That I do not know if anyone has tried it on the 125.
I blew my welder rectifiers last year. Replaced them with 4 x Full bridge 50Amps in parallel. Since then The welder got many harsh abuses and still running Ok. 50Amps Bridges are pretty inexpensive from China and the job OK.
Jim Viau you hooked these 4 up in parallel to the same outputs? As shown in this video, my single 100 watt unit burned out fairly quickly. 150 one still going strong.
Blew my 3-Phase Diode Bridge Rectifier 150A 1200V SQL150A today while welding. Ordered 2 150A 1600v Bridge Rectifiers. Did not have any additional heat sink. Will have to try the parallel route with these and add a heat sink.
Bart Ives i believe a good heat sink is required with these bridge rectifiers. Possibly why my first one blew?
Mark, I have ordered a heat sink and some thermal paste will try it along with a bridge rectifier.
why are you on the ground? and why do you have so much wire out. you cant get a decent weld
Gravity
Your jokes are as good as your welding. All kidding aside it sucked when it quit working on you
@@oldguy59 before the garage I have now, I was changing car parts in the driveway, in the snow. Being on a cement floor is way better to me, and I don't have a work bench (yet).
Maybe this is why my welds are not getting better. Im running the same welder but still ac
I believe the welds can only get good to a certain point and then the limitations of being AC prevent them from being a truly good weld. The low amperage doesn't help much either. These welders are handy for small jobs and inexpensive, but really, spend the money on a better unit? There are many webpages explaining that Flux Core Wire should only be run DC with the gun Negative to keep the Flux slag from being drawn into the weld.
Why not installing a big, CPU cooler with heat-pipe for a heatsink.
I bet that would work too. Whatever the source, I was told aluminum would draw the heat away better than any other metal. I'd say go for it!
Look to me like you didn't reverse polarity for the flux wire, that's why you had a lot of splatter and bad weld
Before the modification this was an AC welder which has no polarity. After the DC modification, the polarity is positive clamp, electrode negative, which pulls the metal and arc into the work piece, and should produce less splatter. At least, that is the theory?
Your welds don't look like you have much penetration in
Seems like too much of reinventing the wheel going on here.
Your stick out is too long..your too fast. Should have had the DC test wire set at 7 also to be fair.
Curtis Sheppard same thought
Have you tray none flux wire?
MAM MAM I do not understand your question. What do you mean?
Mark Young - Outside The Box wire without flux...
MAM MAM This is a gasless unit which burns the flux to reduce the oxygen getting into the weld. Without the flux the weld would be weaker over time?
When u are welding you are moving to fast and I’m pretty sure u dont have enough wire feed
Thank you for the comment. Based on what I have welded since, wire speed should have been faster.
THAT, was painful to watch. Just spend a few bucks on a decent welder. Good deals to be found on Craig's list......
It's a fine modification if someone already owns the welder and wants to improve it.
Thats the easy way out.
Thats why its called a rectfire🥴
better results as a Tog welder son .
Just get the FC 90 from Home depot if you need DC welder.
Looking back, that probably was the way to go. As someone with no welding experience will often do, I was looking for something cheap to start with and see how it goes. I also like the fact that this one can plug into any 110 outlet.
Just bought the FC 90 and I'm happy with it and also 110v outlet very cool
@@NengVang2007 you've convinced me to check it out, thanks!
@@contact4mwy7 get one you will love it only 15lbs and small running great.
Hangin grapes true definition