arc welder/spot welder? Answered

Can an old small arc welder be used to make a spot welder? It's a 60 yr. old Grindl. A stamping on it says input amps 20, sec. amps rated .80- 80, welding volts 20, max open cir volts 80.

Question by hjones47222222 3 years ago  |  last reply 3 years ago


Will my metal welder work ok?

I'm totally new to metal welding but am going to give it a try. My oven/range has a power outlet that reads on it: 125/250V, 50Amps. It has four prongs, three vertically oriented flat ones aligned as a triangle with the center one lower than the other two, and a fourth one top center that's round. My breaker box shows a 50Amp breaker for it. The welder says it's a MIG 170, 240V AC, 20Amps,single phase, 60Hz (Harbor Freight). I think the power I have is actually 220V but I'm not sure. If I do only have 220V will the welder only draw as much voltage as is asked by it - that is, if I only crank it up, say 3/4 of the way, will it draw less than its rated 240V? Or is that 240V just a maximum rating and it should run ok with 220V? It would seem odd that they would sell a welder that won't work for the power their customers would have by default without modifications. Also, where can I get a double socket for that outlet with one having an extension so I don't have to pull out my oven every time I need to weld something? Thank you. Bretina

Question by Bretina 5 years ago  |  last reply 4 years ago


welders for sale

THE VERY BEST HOME MADE WELDER this is the best welder, its so good that I would like to offer, to build one for you. look at the photos, the photos are not the best, but they show the basic setup, when I send it to you it will come in a metal box like any other store bought welder, I WILL ONLY SHIP THE BEST, this welder can weld up to half inch, with good penetration, NOT A TOY ...... there's also a picture I had drawn up for you to so you know I want it to look like. also I would like to tell you that since I am building a box for mine, I think that building another , at the same time would be best, thats why I have waited, do remember I ONLY SHIP THE BEST TO YOU! THE PRICE IS $70 DOLLARS if you think thats too much, go look at welders at a store, that can do as much as this one! then you'll know this is a very good deal! IMPORTANT this welder uses 3/32 welding rods,I will send you some rods so you can have some fun as soon as you get it , it can be modified to work with 1/8 rods , just buy adding another transformer, tell me what you think, at KNOWHOWDANIEL@YAHOO.COM and thats not capitalized if you don't think it possible I will LAUGH! AT YOU! HA written by Daniel Rosenthal Experimenter, scientist, etc.......

Topic by Danielro10 10 years ago  |  last reply 9 years ago


Backpack Welder

Check out this awesome backpack welder; I saw it in a Farm Show magazine.  It would be fun if someone made an Instructable of one of these.

Topic by robbtoberfest 9 years ago  |  last reply 5 years ago


Plastic welder.

Need to purchase one for automotive related purposes. Airless?

Topic by gnarlycreature 11 years ago


the welder with sunglasses

I just ran into this interesting post of an italian woman living in Addis Abeba: https://ferengiaddis.wordpress.com/2010/09/21/il-saldatore-con-gli-occhiali-da-sole/ Since it's funny and explained with humor I wish to share it with you: I can of course translate it into English ;-) "The welder with sunglasses Today a man came to weld our gate, because it had come off a metal rod. He came with a wheelbarrow containing the tools of the trade: a hammer, a few pieces of iron and a welder. This one! https://ferengiaddis.files.wordpress.com/2010/09/saldatrice.jpg When I saw it I ran home to get my camera, deeply convinced that the entire operation had to be documented; and in fact I was not wrong. To connect the welding machine to the wall socket of my living room there was no extension cable. But here no one lose heart for so little: only took a few lengths of electrical cable connected to the least worst and fixed with a few pieces of cloth and the problem is solved. https://ferengiaddis.files.wordpress.com/2010/09/prolunga.jpg Of course, such a link at the end did not have a plug to be inserted into the socket, and when I pointed it out the welder looked at me with pitying air, and carelessly shoved the two bare wires in the little holes in the wall. https://ferengiaddis.files.wordpress.com/2010/09/presa.jpg Only a few sparks, but in the end it worked out great, the welder has completed its work smartly wearing a pair of sunglasses as protection, the power went out just three times and the gate is as good as new. Just for the record, the wall socket is now a bit melted..." I wish there will be many authors here like that "welder with sunglasses" ps: don't try that by yourselves!!

Topic by andrea biffi 4 years ago  |  last reply 4 years ago


Microwave oven welders for $50

I am selling microwave oven welders like the one in the link below, https://www.instructables.com/id/Build-a-Microwave-Transformer-Homemade-Welder/ the reason I'm selling these home made welders is do you know how much work it takes to build one and make a nice case for one, HA! have fun, but for those of you who don't have the time or patients to build one, then BUY ONE! there's alot you can do with onethe scech of the welders I am selling is the PDF below SORRY I DONT HAVE PICTURES YET!the speck's for them are about 70 AMPS (I'm leaving extra space so when I figure how to get more AMPS,there can be just another part installed and you have more AMPS) and for a little extra money you can have it so you can vari the AMPS ( about $20)its air cooled PRICE! for one of these welders is $50 AND $20 for the vari AMP

Topic by Danielro10 10 years ago




Can I convert a three wire plug into a round four wire plug?

Wiring is for an "AC 225 arc welder". It has a round three wire plug on it now but the only outlets I have available are round four wire.

Question by BurtWright 8 years ago  |  last reply 8 years ago


Can a ARC WELDER be converted to a SPOT WELDER?

I have this ARC welder which puts out 50 AMPS, flip the switch gives you 80 AMPS. I would like to spot weld thin metals for a project i am working on, and by all accounts on what iI have seen on the INSTRUCTABLES all I would need is the copper tips attached to the clamp device

Question by yeagerxp 10 years ago  |  last reply 5 months ago


do welders of any and all types interfere with implants such as defiberlators and or pacemakers ?

Do welders of any and all types interfere with implants such as defiberlators and or pacemakers the doctors say yes they can and will but the companies say they can not ever interfere or reset settings?

Question by rayfalcon 10 years ago  |  last reply 10 years ago


Home made welder?

I have a transfomer that appears to be wound with an aluminum winding. Is  this aluminum and will it be safe to make a welder out of?

Question by DWA 7 years ago  |  last reply 7 years ago


cheapest welder for aluminum?

I need to weld 3/16" sheet aluminum for a boat i'm making and want to do it at the cheapest cost. this welder (http://www.harborfreight.com/90-amp-flux-wire-welder-68887.html) says it won't do aluminum (and i'm not sure 90 amps would be enough anyway). Is that true? What if i bought the 180 amp model? Any suggestions for other welders?

Question by ridecruz88 7 years ago  |  last reply 4 years ago


MOT spot welder?

I want to build an MOT spot welder and ive already cut the wiring out of the transformer but i noticed while doing so i scraped off what seems to be the coloring off the primary.  Will this affect it in any way? Also, i can really tell the power of this transformer? can anyone help?

Question by dask13 7 years ago  |  last reply 3 years ago


Hf or rf welder

I have some flexible clear vinyl that I've been trying to figure out how to infuse together for a project I want to make.  I've been successful with vinyl glue (after much tests with different glues and epoxies). However chemical bonding can become expensive.  Ive tried many experiments with melting the vinyl together with soldering irons. Either the bond is not strong enough or it melts through, or it weakens the material too much.  I'd be really interested to see someone make an rf or hf welder that is capable of welding heavy gauge vinyl.  Cheers!

Topic by senica 4 years ago  |  last reply 4 years ago


Diy Spot Welder

Hello, this is my first post here at Instructables. I will get straight to the point. I plan to build a diy spot welder. However, in most of the diy spot welder projects I have looked at, including Hack a Day and Instructables, a MOT (Microwave Oven Transformer) is used. The secondary is rewound with thicker wire, and the transformer is used to step down voltage and step up current. I have heard that these transformers can supply as much as a kiloamp at very low voltages. However, I do not own a MOT, they are too costly to buy, and I do not want to retrieve one from a microwave because- A) Nobody happens to be throwing away a microwave in my area. B)The guys who own the scrap metal and thrown away appliances will only give me a microwave oven at a hefty price. C)I would prefer to live a very long life, and do not want to gt myself electrocuted poking around the innards of a microwave. SO, I did a thorough search, and found that some people made a welder from a stereo amp transformer. Again, I did not own one, but what I did own was an ultrasound generator that was supposed to drive away rats. After making  bloody inroads into it`s innards, I found a transformer quite a bit larger than the regular step downs. It is 5 cm long, 4 cm wide and 1.7 cm tall.  Input voltage is 220 volt AC from the mains, at 60 hertz. Output is 12 volt AC at a maximum of 300 MA. Speaking from experience would anybody please tell me whether this is suitable for a spot welder? Please ask me for additional information, including pictures, if required. Thank you.

Topic by TheLightningConductor 2 years ago  |  last reply 2 years ago


Computer UPS backup transformer into an welder OR spot welder ??????

I have some transformer from my UPS. i want to make it welder.. watch this videos.. Do not talk about microwave ovens transformers . i don't have microwave transformer. can we make it ??? 

Topic by ishan udyoga 5 years ago  |  last reply 3 years ago


I'm trying to build a welder from microwave transformers, but I got this weird looking transformers instead.

I recently got two old microwaves from a junk yard and wanted to build an arc welder with its transformers by connecting both in series and getting an output of around 40V all together. But when I open the microwave instead finding the big chunky laminated iron core transformer as shown by many youtube videos, i found a small weird looking transformers instead. ( as shown in the pictures) I read somewhere stating that the primary coil should at least have 1 turn per volt. However, this transformer only had around 17 turns in the primary. The core was also not laminated and it had a copper wire holding it in place. The primary coil was made of a thick litz wire and the secondary was a very thin wire. Anyhow, I still continued the project and I experimented with one first. I use the same primary and made my own copper wire for the secondary. I made the secondary by using thick copper wire which I found in some antenna wire and I stacked it up and twisted it and put a heat shrink tube on it. Base on a few tutorials i saw i need an output of 20V from each transformer coming from an input of 240V AC. So with 17 turns in the primary i need around 1.5 turns in the secondary. When i finished everything and connected it to the power supply, it vibrated for awhile and then blew the 13A fuse in the plug. So i added a light bulb in series hoping to increase the resistance and reduce the current but this time nothing happen and it didn't even vibrate but the bulb did light up. I think its because the primary coil has a resistance around 5 ohm and the bulb have resistance of 100 ohm so the potential differences is very low on the primary coil. I am not sure why isn't it working. Please help me as i can't find any tutorials on how to make a welder with this form of transformer. There were no other transformer in the microwave so this was definitely the main transformer. Is the problem because it has too little turns in the primary coil or it has too low resistance? I don't know please help me. Thank you!!

Question by KhayhenS 4 years ago  |  last reply 4 years ago


What is the duty cycle of a welder? Answered

Is a 6% duty cycle good? Bad? Terrible? Worth blowing up?

Question by bowmaster 9 years ago  |  last reply 5 years ago


what is the safest type of welder?

Exactly what the title says i know they are all dangerous but which is least dangerous and what about those homemade ones with microwave transformers or the one with batterys and jumper cables

Question by BIGHAIRYDUDE 8 years ago  |  last reply 8 years ago


will build home made welders

Welders for sale THE VERY BEST HOME MADE WELDER this is the best welder, its so good that I would like to offer, to build one for you. look at the photos, the photos are not the best, but they show the basic setup, when I send it to you it will come in a metal box like any other store bought welder, I WILL ONLY SHIP THE BEST, this welder can weld up to half inch, with good penetration, NOT A TOY ...... there's also a picture I had drawn up for you to so you know I want it to look like. also I would like to tell you that since I am building a box for mine, I think that building another , at the same time would be best, thats why I have waited, do remember I ONLY SHIP THE BEST TO YOU! THE PRICE IS $70 DOLLARS if you think thats too much, go look at welders at a store, that can do as much as this one! then you'll know this is a very good deal! IMPORTANT this welder uses 3/32 welding rods,I will send you some rods so you can have some fun as soon as you get it , it can be modified to work with 1/8 rods , just buy adding another transformer, tell me what you think, at KNOWHOWDANIEL@YAHOO.COM and thats not capitalized if you don't think it possible I will LAUGH! AT YOU! HA written by Daniel Rosenthal Experimenter, scientist, etc.......

Topic by Danielro10 10 years ago  |  last reply 3 years ago


Welder Help! (Changing the spool)

Hey guys, I bought a mig welder about two months ago and the spool's out of electrode. I bought a new spool to be put on, but I'm not sure about the procedure. Could anyone help me???? I looked for the manual on google, but failed to find it (I bought it used on ebay). It's a Clarke 130EN Thanks, -Josh

Topic by T3h_Muffinator 12 years ago  |  last reply 12 years ago


PLAZMA CUTTERS & WELDER COMBO's Answered

I have been looking for a PLAZMA Cutter/welder combo to reduce the amount of welding equipment I now have.I am interested in  the MULTIPLAZ 3500 because of the different material it will cut  and the use of water and water/ alcohol as shield.  Please give your  opinion,     I would be using it on a small PLAZMA table. Thank you, Liffan

Question by liftfan 7 years ago  |  last reply 7 years ago


robotic arm arc welder

Is it a robotic arm capable of arc welding feasible for a diyselfer ? I spotted some robot arms for cheaper than 200 $ over the web . Vantages for the operator would be no weld fumes breathing , no uv rays and such ..

Topic by gabdab 5 years ago  |  last reply 5 years ago


Modding a cheap MIG welder?

I recently bought a cheap mig gasless mig welder and I was doing some online reading about it. So I found out a mig welder should be DC, with gasless having the clamp at + and the torch at - . However when I looked at the schematic (in the images) and inside the welder to confirm it, and it was AC. So it turned out really cheap welders are ac. So my I want to try mod it to be DC. My question was, what diodes should I use? What Capacitors and capacitance do I need? And how do I design a Choke? I was looking at getting this diode: http://www.ebay.com.au/itm/MBRP400100CT-400A-100V-SBD-Schottky-Barrier-Rectifier-Diode-Module-/160930207205?pt=AU_B_I_Electrical_Test_Equipment&hash;=item25783015e5&_uhb=1  And then putting two of them together to make a full wave bridge. Would a Schotty diode Work? Or do I need a stud diode? And about what capacitance do I need? Would lots of 2200uF 50v capacitors in parallel work? Could I put in a variable ballast? and where would it go, on the 240v side or the output? Lastly, could I also add a modded microwave oven transformer for low voltage high current in parallel to boost the power? I guess I would have to wind it to have a similar voltage. Thanks

Question by makincoolstuff 5 years ago  |  last reply 5 years ago


Making a better spot welder....

I am in the process of building a proper spot welder from scratch. Proper more in terms of the electrical and electronics part but not so much in looks ;) My problem now is to find useful info on what power levels are required for certain tasks. I realise that welding thin sheet metal won't need as much time and amps as welding a 3mm stainless steel rod - but what is a "good" power level? I watched a bunch of Youtube videos showing various approaches but for many it seems the producer had no clue about the difference between creating a short with burn marks and a weld... Especially when it comes to creating battery packs with a capacitor bank as the main power provider you can clearly see the device burns holes but does not really create a welded spot. On the other hand there are a few videos showing spot welder made from a MOT that seem to produce a proper melted and welded connection. When I used a proper spot welder at work it had timing settings, power levels and even a feature to adjust how the current rises.... Not to mention a gauge that checks the pressure and only activates the welder once the set point is reached... There is a ton of info out there that after a thausand words still tells you nothing you need to know :( So is there anyone here who can shed some light on the actual process of spot welding in easy words for everyone to follow? I am aiming for a max output of around 400A @ 1.5 -2.5V with an adjustable shunt in the transformer core to avoid oversaturating the core. In a later stage I will add power control over the primary side but until then it is only time control, from a few ms to a max of 5sec if the damn controller arrives one day. Big questions: 1. Is a power control really required or is it possible to cater from thin to thick just by using different timing settings? 2. Since a MOT is used for the power supply: Is it better to leave the shunts out to fully avoid saturation by adding an inductor in line with the primary or is it still better to adjust the shunts under load to get the maximum power possible? 3. Aluminium and other materials benefit from using AC but would be good to have a DC output too, if so then what materials really need DC? 4. All I could find is that copper is used for the electrodes, due to resistance and heat transfer - are there other options apart from using copper? 5. Tricky one: I would prefer to use the secondary winding as the new primary to avoid core saturation and to lower the load on the power outlet. Where can I find very thin copper bar material that I can coil up and insulate as I would quite a few more turns to get at least 1.5V out of it? Just don't like the idea of spending days rolling a copper bar thin enough.... For the advanced model at a much later stage: Of course I would like to be able to use a proper power control instead of a motor dimmer or similar. For obvious reasons an inverter microwave jumps to mind. But after checking one I noticed one big problem: there are not really that many windings on the primary of the transformer at all! Same way our modern switchmode power supplies only use a few turns these things do exactly the same. After some quick and dirty initial tests I realised that even a single turn of thick wire already results in over 20V on the secondary. Wasted a lot of wire and time making one coil with 5 turns less and one with 10 turns less but the system would not even start with it. Seems these things need a fixed inductivity on the primary that matches the frequency used, in my case 36kHz. Would love to overcome this problem so I can at least go down to a single turn to get under 5V on the output side as space is non existing on these inverters. Can I cheat? Do I need to change the circuit to match the new primary coil? Am I thinking in the wrong direction altogether here? And added bonus would be to be able to adjust the power from around 15% to 100%, so far the electronics don't allow anything below 45%. Is it possible to drive these inverters in resonance? (Ok, off topic as I would like to use this for a beefy HV supply) Last thoughts: I know people already used Arduinos and Raspberries with displays and all but so far I have not found anything that shows how to do it properly. Seems all that counts is to create connection one way or the other and to call it a spot weld even if it is just a burn hole from discharging a capacitor bank through a needle like electrode.... For obvious reasons I don't want to create just another spot welder that makes a professional pee himself laughing about it. IMHO nothing beats personal experience with something but I don't really like wasting my time by trying what other people alread did a long time ago. So if YOU already built a MOT based spot welder and used for more than a few spots I would love to hear from you! Let me know what type you used, what problems or shortcomings you noticed or where you feel it just does not work out the way you expected it. From simple things like always getting bad sparks or arcing, over how easy or hard it is to get consistand results to whatever really annoys you while using your homemade spot welder. I hope that your feedback here will help me to write an Instructable on building a spot welder that does what you expect it to do, not once or twice, but everytime you use it. Mechanics might vary the same way the electrode style does but the weld should always be a proper weld that won't tear apart ;)

Topic by Downunder35m 1 year ago


Is there a way to convert a generator into a arc welder? Answered

Is there a way to convert a generator into a arc welder?

Question by stevnmilr 10 years ago  |  last reply 10 years ago



has anybody build a stitch welder?

 i want to replace the batteries of my power tool and stitch the batteries together.

Question by rickyt 9 years ago  |  last reply 9 years ago


small hobby resistance/spot welder?

I want to weld small steel wires (the size of guitar strings - +/_ .035) to make small sculptures. Solder works, but is not fast or strong enough. Can I make a welder to run on 115VAC?

Question by Dweevil 9 years ago


Can a stick welder Weld aluminium ?? Answered

My dad has a mig welder and i dont want to buy a gas kit for that so ive been thinking of buying a cheap stick welder WIll it be able to weld aluminium angle or box aluminium

Question by stephenniall 9 years ago  |  last reply 4 years ago


Turn an ATX Power Supply in to a Welder? Answered

I was wondering if I can turn an ATX power supply in to a welder: Before I write down the specs/amps of the power supply, I want to say that I have no experience in welding, I'm wondering if it's posssible to make a small welder out of an ATX power supply. Is there some kind of minimum current that you have to pass to start welding (softer?) metals? The lower the voltage the better right? I didn't give a lot of information, Because I don't know what to ask... Thanks :)

Question by Yonatan24 3 years ago  |  last reply 2 years ago


Trying to build a Alternator/generator welder?

Ok im trying to build a Alternator/Generator welder. i want it to be able to do Stick, Mig, and Tig. So other words three different circuts on one board. so i can switch between the three. 1. how should i control current: in between the battery and field post or after from the positive post from the alternator? 2. how to control the voltage: same as number 1 between the batt and field or from the batt post on the alternator? Also i understand the consant current constant voltage thing. that will be provided on the three circuts. Right now im just working on the stick welder circut ill ask about the mig and tig circuts later or you can pm if you have any info on them. im just trying to piece this togeather step by step. Any help will be great. and yes i know this is a very big project, and will require alot oof time to do.

Question by dmm1542003 6 years ago  |  last reply 3 years ago


AC MOT Welder Voltage Issue

Hello everyone, I've been working on an arc welder based on instructables like https://www.instructables.com/id/Small-110-volt-arc-welder-NYDG/ but I need some advice. Most tutorials on here suggest two paths to success, either winding two MOTs with as much 10 gauge wire as possible, hoping that the voltage output in series will be close enough to 40V, or using multiple small transformers, also in series. The problem is, all this series stuff really cuts down on the available amperage, so I'm wondering if there's a different way to get high amps and volts simultaneously (obviously without surpassing the available 2400 Watts, energy in = energy out). I think I have a way to make two MOTs which run at low voltage but high amperage also have high voltage. I've made a high frequency circuit to assist in starting an arc, which you can see attached (it works phenomenally, and I've been able to make it run on 1 amp). Since the output on the HF part goes through a torroid at the far right (where it meets the welder's output), would it be possible to wind the torroid with, say, 5:20 turns, to basically take the 120A (10.8V) I get from the parallel-connected MOT transformers and overlay a low-amperage but higher voltage on it, to make arc start/run easier? The welder just won't run at 10.8v, so other than rewinding the secondaries, what about jumping the voltage up a little via the output torroid?

Topic by reakter 6 years ago


Wireless TIG welder foot pedal?

Has anybody ever heard of or created a cordless foot pedal (remote) for tig welding? I hate having to buy new foot pedals for our Miller Synchrowave TIG/ Stick when the power cable gets cut or burned through. Thought about "bluetooth" signal.

Question by bobhdus 9 years ago  |  last reply 5 years ago


Will this capacitive discharge welder design work?

I am planning to build a capacitve discharge welder so that I can tab weld my battery packs, and I have no intention of paying 2K plus.  I recently came across a fairly simple design, and was using it to design my own.  If anyone that has built one of these, or knows how to, can look at this design in detail, and inform me if I have the right componants, and in the right order, it would be greatly appreciated  *** Please, I know the dangers and risks to what I plan on building so please do not express your concerns here.  Everything has risks, but without risks their can be no reward.*** UPDATE I added a new diagrahm with the opto-iso and relay that you two recommended, not sure if its right yet, but its a work in progress

Question by supramp 7 years ago  |  last reply 6 months ago


Need Help With A Mini Spot Welder

I've been trying to gather information to build a welder for a special application. The use is for welding the commutator tabs and magnet wire that passes over them for small DC motors. While there are specialized and often automated welders made for this purpose, they are both large and very expensive and really intended for industrial users. I have been able to get small bits of information as to how others have done this, but it's been difficult to get the whole project laid out (there is apparently some "secrecy" involved here!?). The materials being welded (soldering isn't a preferable way to make this connection...these motors run hot and very fast) are the brass commutator tabs (approximately .030" thick material about .060" wide formed as a "U") and the copper magnet wire used to wind the poles that then passes over each brass tab...from #23 awg to #28awg. From what I've been able to gather, people have done this on a "homebrew" basis using 6V automotive battery chargers/starters that can deliver around 30 amps or more. I have very little knowledge of electronics and none at all about welding and circuit design, but am looking for information on how I might proceed after sourcing the charger/starter. I'm guessing that the "negative" cable would be adapted to use as a clamp at the commutator and would also double as a heat sink to prevent damaging the commutator and that the "positive" cable would somehow be adapted to hold some sort of fine rod that would touch each com tab to complete the welds. -Maybe a footswitch could or should be used to start/stop the weld? -Is the positive cable simply used to hold a rod for the "spot weld"?, or are there other pieces that need to be added? To my mind, it would seem that simply touching the positive to the commutator tab to make the weld and complete the circuit would simply trip a breaker at the panel or any protection device on the charger(dead short!?). -Any other information or thoughts? Thank you in advance -john

Topic by havlicek 10 years ago  |  last reply 10 years ago


How to limit welder current (heat)? Answered

Hi All, I admit to being electrically dumb, well one step above dumb, I'm a software engineer not electrical engineer, but I don't even know enough enough to be dangerous yet:) I'm going to be converting an ac welder to dc. It's a harbor freight 90 amp flux wire job, comes from the factory as AC for some unknown reason, but should be DCEN for FCAW welding. There are several walk throughs availabile online. I don't know the rules for linking to other forums, so I won't post a link, but you can google 90 amp welder dcen conversion if you want details. I attached an image of the circuit I got from a post by bluecatfish onweldingweb. I'll be taking the transformer output, running through a full bridge rectifier to convert to rippled DC, using capacitors to remove ripple, and lastly running through a torroid inductor. Another problem with this welder is it only comes with high/low power settings. The low is still too hot and burns through thinner metals.  I want a way limit current further, but maintain voltage for a stable arc. I'll be adding a bleeder resistor to drain the caps, which gave me an idea. At first I thought to use several more resistors in parallel with the bleeder to reduce current. I imagine this might work but be horribly inefficient. It would still use all available power from the supply, just converting some of it to heat, leaving less power for the arc. I've read that adding resistance in series will reduce current, but won't that drop voltage available for the arc? Then I was thinking, I have a motor speed control for a router. I believe this is a pwm. Could it be used to chop the mains input (120v 20a) to the transformer and reduce overall output without effecting voltage(I've read this is 38v 80a in the factory state before my mods)? since I'm adding capacitors downstream, will they just discharge too fast leaving me with ripple/pulsing? If so, how would I slow the discharge rate? (I'm looking at 3x or 4x caps 22,000uF @65v in parallel on a bus bar, so 66,000 or 88,000uF total). Sorry if in not making sense, as I said in the intro, I have a lot to learn, and right now, the more I read, the more confused I get. Edit:  After more research, and to hopefully use correct terminology, I think I'm talking about using a current divider when referring to multiple resistors in parallel to the welding leads. I think I'm referring to a switching regulator when I suggested using a pwm to chop the transformer input. Can either of these work like I'm hoping? Is there a better way, that is relatively simple?  Thanks in advance for your patience and help. 

Question by DonaldF9 3 years ago  |  last reply 2 years ago


how can I vary amp settings on a welder. Lincoln 225 AC?

I have a Lincoln AC 225 welder. I would like to be able to vary the amp settings between the set stops that are on the welder now. Any one know how I can do this?

Question by Geo56 4 years ago  |  last reply 4 years ago



Could I use a 550w PSU as a welder instead of two microwave transformers?

Question by jking1984 10 years ago  |  last reply 9 years ago



how can I convert an ac welder to a dc?

I have a microwave oven transformer welder that I made and it works ok, but I woul like to convert it to dc. Any information will be appreicated. Thanks

Question by sakimoto 8 years ago  |  last reply 6 years ago


can you turn your wirefeed welder into a plasma cutter.

Can you turn your wirefeed welder into a plasma cutter.  if you replace your gas line with an air line  and connect the cables to the  ,- terminals?

Question by smackit 9 years ago  |  last reply 9 years ago


How to choose the right capacitor for Harbor Freight AC Welder to DC Welder conversion? Answered

I'm watching this series of videos about improving a cheap harbor freight welder. Right now the step is converting the AC to DC. It seems like the guy is just using whatever components he has laying around or that are the cheapest but I want to make sure to get the most power as possible. Here's the AC to DC conversion video:  https://www.youtube.com/watch?v=NoYN4vx1WU8&list;=PLd_DTtq1stJJ4C0qlUnxqBvrfLXLKDyYr&index;=1 Here's a link to the Harbor Freight page with the welder specifications: https://www.youtube.com/watch?v=NoYN4vx1WU8&list;=PLd_DTtq1stJJ4C0qlUnxqBvrfLXLKDyYr&index;=1 It says on the specifications page that the open circuit voltage is 26 volts, does that probably mean that that's the max output voltage at which the welder operates? Anyways, here are my questions: 1.Can a capacitor be fully charged by a lower voltage than it's rated for? For example, the modification in the video uses a 50V capacitor to store charge from the transformer of the welder, which I'm assuming is a 26 volt or less source. Will it still reach it's 46,000 microfarad charge storage potential or does the charge storage potential vary based on the charging voltage? In which case could the capacitor store more charge at a higher voltage, a lower voltage, or wouldn't it make a difference? 2.For the rectifier, assuming the max output of the welder is 120 amps at 26 volts, I am thinking that the guy in the video should have used a rectifier rated for at least 120 amps, probably somewhat more than that to be safe. But instead he is using a rectifier rated only for 100 amps at 1600 volts. That's it. Basically what do you think of the modification. Are those components in the video adequate, the rectifier and the capacitor, or if doing this modification would you have selected different perhaps higher rated components. I have a habit of thinking that I'm too smart to follow instructions exactly and then wondering why things go horribly wrong when projects, recipes, etc. don't turn out.

Question by avocadostains 3 years ago  |  last reply 3 years ago


HOW CAN WE MAKE BATTERY TAB WELDER?

I WANT TO REBUILD BATTERY PACK SO CAN WE MAKE BATTERY TAB WELDER AT HOME?

Question by ustech 8 years ago  |  last reply 3 years ago


I have a hobby mig welder. How do I fix it ?

I have a hobby mig welder it seems feed wire fine and the gas flow is good but when the arc is struck it sputters as if the power source is low. How do I fix it ?

Question by chs247 10 years ago  |  last reply 9 years ago


How can I build a 220V welder using 220V microwave oven transformers? Answered

I read TimAnderson's Instructable on building a homemade welder from microwave oven transformers, but that instructable is for a 110V setup, what should I change to make it work using 220V transformers on 220V. (I already gathered all the materials...)https://www.instructables.com/id/Build-a-Microwave-Transformer-Homemade-Welder/ ....Link to TimAnderson's homemade welder?

Question by inserbot 9 years ago  |  last reply 9 years ago