/diy/ - Do It Yourself

so ya making making a spot welder

This is where I'm at now. I'm removing all the secondary wiring at the moment. It's held on and separated by tape. The tape is old, dried out, and crackly.

>>132431
If it's big enough, yes. Since I took the E-I frame apart, I can rewind it with anything in anyway I want.

http://www.youtube.com/watch?v=AY-SLCLdn6g&feature=related

That took forever. It seems the primary is in a plastic shell. I may or may nut cut the shell away. I've not totally decided on what I want to do with all the parts, so I'll mull it over until tomorrow.

brb

>>132470
I'm going to bed, so I'll not see any post until tomorrow.

>>132419 What are you doing tonight, /diy/?
Tonight's project, sticking a bunch of LEDs in a colander and programming them to scroll math equations. Tomorrow's project is wearing it on my head to a Doctor Who themed dance rave.

you just gonna put it back together without doing any experiments on it?

12-3AWG wire

>>132472
That's bad ass.

>>132478
Experimenting today.

Winding this stuff was a real bitch. I'm doubling over the 12-3 wire, but can only wrap it about 3 times. Basically, I made it 12-6.

I'm at this stage now. Warming up my soldering iron to keep the I plate on.

I thought it was worth a try, but of course the solder didn't take on that big block of metal. lol Guess I'd need to just weld it. However, I have a large C-clamp that will work for testing purposes that will hold it together.

>ugly solder-corroded pure copper tip
>tinning how does it work?

This would have been quicker my blow torch.

Still, the solder went all the way through to the other side. So it is good enough for me.

Second tinned wire. I'm taking a break from here to set up other stuff.

So, if this transformer becomes a welder of any kind I thought it might be best to have a switch that wouldn't have the possibility of melting on contact and sticking in the ON position. I also wanted to test out a few other things in a similar manner. I have this old non-functioning Dremel and decided the carbon brushes my make a switch that wouldn't melt to something. So, I started slapping things together.

I doubt the solder will last if this thing gets hot, but it's stuck to the metal at least.

I made two of these and this isn't the final resting place for this one. I'm just trying to see of different ways to attach the switch arm which will be attached on the other side or the transformer.

>>132815
the insulation is way too thick
use different wires, you'll be able to wind more turns

>>132892
Most people don't even remove the insulation and wind it 3-6 times. The more you wind it the lower the amperage and higher the voltage. The less you wind it the higher the amperage and lower the voltage. For welding you need seriously high amperage.

http://www.techelex.com/2011/05/how-to-build-your-own-spot-welder.html

>>132894
Forgot pic.

What's the best inductive ballast to use inline to prevent inrush problems?

Here's a good page on making MOT welders,

http://www.home-workshop.com/MOTWelder.htm

Alright, its GO TIME!

I tested it with the carbon tip, but it didn't work at all. I checked the resistence through the carbon tip and it was 0.2 - 0.4. Checking the resistence from the tip to the other end of the wire that goes through the transformer had the same results. But, metal on metal is the way to go it seems. I didn't make the carbon graphite switch and instead opted for a standard power strip.

Here's what the current setup looks like.

In action shot. This is from a video still. It worked! I also didn't trip any breakers, the transformer's primary and secondary didn't get hot or even warm. The tips even stayed cool to the touch (unplugged it first). None of the lights dimmed in my house. I did take the precaution of having only one light on and nothing else plugged in anywhere, even my PCs. Though everything is on a different breaker.

I didn't have welding eye protection so I didn't look right at it. I did have a face shield, leather gloves, and ear plugs. I watched it through the camera instead.

Here's the top of the weld. These are the metal covers from floppy drives I think. You can see where I tapped it instead of holding it down. I didn't want the tips to get stuck together until I knew what was going to happen.

Bottom of the weld.

I pried the two pieces apart enough to take a pic between. It was rather solid, but more welds would be needed to amount to anything obviously.

The inside of the weld after prying it fully apart.

http://www.mediafire.com/?bgpv5onjgmwqy62

Here's a video of this spot welder and the pieces being welded together. you can see the bottom tip really stuck.

This transformer came from an old stereo (LP, cassette, radio), I tore apart the other day. Now I just need to weld the I section back on the E section of the transformer block so I don't need the C-clamp. I should also make a good set of arms and tips for it, now that the testing was a success.

I believe if I had 2 of these hooked up I could do 1/16" rod arc welding with them.

Here's some specs about the transformer build,

The primary winding seems to be 22AWG with the wire for the plugin being 18AWG. The primary winding is wound around in the center and the old secondary winding was wound on top of that. I removed only the secondary winding. I used 12AWG 3 strand wire and doubled it to make 6 strand. I wound the 12AWG around the primary winding almost 3 complete times with the 3rd wind being where the wire ends come out at. I used vise grips to hold the 6 strands of wire while I used another pair of pliers to twist the ends together. Then I tinned the ends with solder (40$ tin, 60% lead, .062 dia). I used a standard cheap power strip to plug the transformer into. I think it's hooked to a 20 amp breaker, but I'd really need to double check that. The house wire for that outlet is also 12AWG 3 strand. There was no ground, but I'll install one on the transformer block later.

I tested the continuity from the metal transformer block and the 6 strand 12AWG I put on it to make sure it was not shorting out on the block before I ever plugged it in. It wasn't.

This pretty much concludes this. Any questions?

I figured I'd post here instead of clogging up the board with another thread and pushing someone else's thread off the board.

I took the old secondary wire from the transformer and wrapped it around this pipe.

I attached a standard 9v battery to it.

It took quite a bit of time to get that done. Coin for size comparison.

No switch, but it doesn't need it. I just pop the wire in and out of the snap.

The 9v battery produced lackluster results. The wire was fine, but the battery got VERY hot in only a few seconds. Time for another power source, one with more amps.

I have several PSUs from old PCs. Thier outputs are 3-5-12v ranges. I was testing a 12v low amp one here, but the PSU didn't like it.

So, I moved it from that connector to one of the molex connectors. Specifically, one of the 5v 30amp connections. This produced far better results. The wire was slowly getting warm on the pipe and a bit hotter on the single strand.

I think I'll wrap another set of coils on this pipe to keep temps down, up the voltage, and make it more powerful. Imagine what you could with a big MOT set up as an electromagnet.

Also, here's a video of the electromagnet in action; switching it on and off,

9.8megs
http://www.mediafire.com/?a2e0898ajcibf9p

Awesome project OP. I'm totally jealous I don't have a transformer like that laying around or I would do the same thing. I def know to keep my eye out for one.

>>133218
You can make one. All you need is lots of wire and some metal. It's better to have it laminated, but solid metal will work too, it'll just have eddy currents in it and not be as good. However, for a powerful electromagnet, you only need a really small transformer about 1-1.5 inches across.

>>132894
oh ok, thanks for the info.

I wrapped more wire on the pipe and added a plug in for a regular outlet.

I made sure to plug it into a power strip (which is labeled "surge protector" on the side and it has a light that reads, "Protected" on it.) When I flipped the power strip on the electromagnet jumped to life and start dragging metal crap towards it from about 2 feet away and it was almost pulled out of my hand. It also made a LOUD vibration hum during the 2 seconds it worked. Then the electrical cord it was attached to and the power strip both fried. It seems the electric cord from a PC was too small (18awg wire) and the power strip blew a trace on the PCB (pictured.)

It should also be noted that the power strip had nothing in it at all to protect from a surge. All the PCB had on it was a switch and some stuff to power the LED for the "protected" light. Any inrush coming through it would fry your equipment before a trace fried on the PCB.

So, I patched the trace and went back to experimenting with the PSU's power supply. I also noted that with the PSU's power, the electromagnet affected my CRT monitor at 5 feet away causing the screen to become purple while the magnet was on.

>>133388
>the electromagnet affected my CRT monitor at 5 feet away causing the screen to become purple while the magnet was on.
5 feet and it's having an effect? That thing's not half powerful.

>>133389
Yeah, at 5 feet its distorting the color CRT screen at 2-3 feet I can't get it closer because it affect the picture structure, not just the color. I didn't want to magnetize my CRT and spend half the day trying to degauss it.

>not half powerful.

I'm not sure I understand what that means. Can you elaborate?

>>133392
Ha, http://dictionary.cambridge.org/dictionary/british/not-half
>used in spoken English to express a positive statement more strongly

>>133394
Oh, I thought it was referring to a tech term on magnetic fields and not the usual colloquial term. It seems the sentence structure is missing a word or two then. Perhaps you could rephrase it?

>>133394
>used in spoken English to express a positive statement more strongly

In America its usually used for negative statements.

>>133395
It's not missing a word, it's just an apparently local turn of phrase. I was effectively saying "That thing is very powerful."

>>133398
I see. Yeah, here "not half" is negative.

>>132419
bumping this thread

I just got in a 960 watt microwave. Here's what the inside looks like. That's one massive capacitor.

Not sure what I'll do with this. If I take apart another 40 microwaves, maybe I'll make a railgun.

>>135963
You haven't seen massive, you can get 'em as big as pop cans and bigger.

Here's the transformer from the microwave on the left compared to the Stereo transformer on the right. The stereo transformer came out of a 560watt stereo, fyi.

>>135966
True, there are some really massive ones, but I don't have those in my hand right now.

I started working on the microwave transformer today. I had no clue what I was getting into with this one. The Stereo transformer was far easier to work with.

On this one I decided to go all out and use 10-3 wire doubled over. That means it had 3 coated wires and 1 ground wire all at 10AWG. It's the thickest wire I have. Doubling it over means there's 8 wires. Coin for size comparison.

Cutting the welds. The welds on this was were not nearly as deep as the other transformer. It popped right off without any trouble. This is also where the batteries in my camera died. The next few hours were spent trying to get both coils out, squeeze the 10-8 wire into it as a secondary, and get the primary coil back on all without having it short out somewhere. The secondary must have shorted out half a dozen times while I was trying to get it in. I kept testing and testing and applying more electrical tape, etc. I had rounded off the edges on the MOT just to lessen this sort of problem or I'd never had got this thing to not short out.

Here it is right now; the one on the left.

This is hours of work. I had to use 2 bench vises and 2 C-clamps to get everything squeezed in. The final test proved nothing shorted out!

Here's the thing though.....there's only ONE winding on that secondary. That's all that could possibly fit. I have no clue at all if that is even remotely going to be any good at all. I might end up with 200amps or nothing at all. I'm not up on the windings thing. I know more windings = more volts/less amps and less windings = more amps/less volts.

I'm taking a break now and will rig it up for a test firing later on. I will probably put a ballast on this one just to be safe.

http://www.dansworkshop.com/2008/03/homebuilt-arc-welder/

>>132831
I used a cheap iron for a long time, had the same eaten away tip until i grinded a nail and used it as a tip. Worked like a charm, even when soldering surface mount stuff.
pic quite related

>>137098
Good idea.

I twisted the ends of the wires and crudely tinned them. I also put a 25w light bulb in-line on the primary side just to see what would happen. Nothing happened; which is what I wanted; other than the light bulb turning on (I'll make a bypass switch that will allow the light to be bypassed then turned off once the unit is on). I then removed the light bulb and hooked the transformer up without the light bulb.

You can see the setup in this pic with the light bulb wired to turn on. The idea of using the light bulb then manually switching a bypass on and turning the light bulb off is meant to absorb any inrush there is. Later I'll probably just make a circuit to do this for me. The metal box the MOT is sitting on is actually grounded. fyi.

Remember, this MOT has only one winding of 10 AWG 8-strand wire.

The test was a success! This makes me wish I had a clamp meter. I really want to see which transformer has more amps and how many there is.

Here's a video of the test weld. There was an upload error at 99% so I don't know if the video will work right. Let me know if it won't play properly,

>10.72megs
http://www.mediafire.com/?k71cj181w7v78a3

Weld pics. Side 1

Side 2

Inside after breaking apart the welds.

>Handbook for Resistance Spot Welding
http://www.millerwelds.com/pdf/Resistance.pdf

Nice bit of info.

I love you guys. Keep it up

>>137355
/diy/ is the best board.

Any way to archive this thread? One of the best I've seen since /diy/ inception.

>>137362
In most browsers, click on,

File>Save Page As> then save where ever you want. It'll make an htm file and a folder. The folder contains all the info for the htm file so they must stay together.

>>137365
Doesn't that just save the tumbnails?

>>137366
Correct. I normally do that and download all the images too with FlashGot/Get or DownThemAll. There's a plugin to save threads, but I don't know what it is. Ask, /g/.

>>137362
http://chanarchive.org/4chan/diy/34955

>>137377
Oh yeah.

The real problem here is getting the duty cycle up to reasonable times to turn these into arc welders. The more transformers with more secondary windings on each should help keep the load off the primary and keep them cooler while giving better amperage. A single transformer may output a great deal of amps with few secondary windings, but it's duty cycle will be extremely short because it will over heat very quickly and burn out. A single transformer with more secondary windings will run cooler and create less amps. The duty cycle can probably be increased if the output amps are regulated so you can use less amps instead of the max the transformer gives. Someone suggested in another thread to try a light dimmer switch on the primary side in order to adjust the amps on the secondary side. Another suggested to use a dielectric coolant like mineral oil (transformer oil) and heat exchanger/heat sinks.

For a spot welder something like 6% duty cycle might be okay for medium to light jobs since you are only tacking small welds whose weld time are extremely short. 6% duty means 36 seconds of welding time and 9 minutes 24 seconds of cool down time; though the 36 seconds of welding time would be spread out over the course of 10 minutes and not continuous. (10 mins = 600 secs; 600 secs - 6% = 36 secs; 20% of 600 = 120; 30% of 600 = 180; 50% of 600 = 300 secs/5 mins; 75% of 600 = 450 secs/7.5mins). The higher the duty cycle the more work time you can have and the less cool down time need.

Some info on duty cycle.
http://www.zena.net/htdocs/FAQ/dutycycle.shtml

>Basic Tips to Improve Stick Welding
http://www.millerwelds.com/resources/articles/index.php?page=articles16.html

>Welding Machine Duty Cycle Facts
http://www.markthewelder.co.uk/id51.html

Here's my selection of aluminum heat sinks. I'm trying to come up with a design that will incorporate some into a transformer oil (mineral oil) cooling unit. I'm thinking of having some attached to the transformer with thermal paste; like the little ones stuck right to the primary windings if they will fit. Also, have them stuck to the outside and inside walls of the metal housing the transformer and coolant will be in. Outside under the transformer I'll have a vent fan to blow across the entire unit.

Hopefully, this will vastly increase the duty cycle.

Any input on the design would be appreciated.

Today I got some copper cable lugs and some solid copper 4AWG grounding wire. I couldn't find any transformer/mineral oil locally, I may need to order that. Here's some pics of attaching the lugs. I had to bring in some backup heat from a blow torch to solder these on with silver bearing solder. It doesn't show it in this pic, but I used a second pair of vice grips on the wire to act as a heat sink to protect the insulation going into the transformer so it wouldn't melt. The black electrical tape still melted on the fire side of the vice grips.

Attached. You can see some of the older solder had dripped out before adding the new silver bearing solder.

Second lug, it went a bit smoother since I could bend it around more.

This is how I'll be doing some testing with this. I'll just be using heavy duty battery cables and a 3/32" 6011 mild steel welding stick. I'll not be doing actual testing until I get some mineral oil first. I don't want to take the chance of the welding stick getting stuck and frying the transformer. If it can't do welding sticks then I'll need to add another transformer to the equation to raise the amps even more. At least I have proper welding gloves and welding helmet now.

http://www.gowelding.org/Basic_Welding.html

Some nice basic welding tip in easy to read short format.

>>139323
>>139326
>>139328
>>139335
I don't know why, but these pics remind me of those action snap zoom shots in Army of Darkness where Ash is making the mechanical hand.