spot welder

[Anonymous No.1286490]

I only need to weld 4 spots, I don't have a giant transformer or a thick cable
any other options?

[Anonymous No.1286492]

Spots on WHAT? We can't waterboard you over the internet to get details.

If you have nothing suitable then consider another fastening method within your equipment capabilities.

What PRECISELY are you doing?

[Anonymous No.1286497]

>>1286492
batteries!

[Anonymous No.1286500]

>>1286490
Lots of DIY spot welder instructions on the web.

That cable looks OK. But I can't tell. You are going to need a method to hold the electrodes firmly on either side of the work. For a quicky project, I'd try to do something with a toggle clamp (pic related). Mount to a piece of wood and rig the electrodes to the clamp and wooden base (non conductive). Wood will probably get the crap charred out of it. But it will survive for 4 spots.

You will also have to rig up some method of rapidly switching the 120Vac input. From what I've seen, a good spot weld requires two (or more) rapid pulses in quick succession.

[Anonymous No.1286504]

>>1286497
>lithium

enjoy your house fire, dumbass

[Anonymous No.1286519]

>>1286504
guilty as charged

[Anonymous No.1286527]

>>1286504
>>1286519

Do it outside, away from anything flammable with a bucket of sand next to you.

Wear welding gloves and a face shield. Don't wear any synthetic fabrics.

Don't lean in close to the battery while you are welding it.

If the battery starts to smoke, bulge, or heat up, dump the bucket of sand on it and walk away, remembering to unplug your diy welder.

You can keep water nearby to treat burns, but do not use water to fight a reactive metal fire. Or an electrical fire for that mater. If you have the correct extinguisher for metal fires (you might in a workshop) you can use that. Otherwise just smother it with sand.

Pretty much safe if you take these precautions.

[Anonymous No.1286530]

>>1286527
Also you're gonna want to weld in very short pulses to avoid overheating the batteries.

Since we're only welding tabs on batteries we don't need a huge amount of energy, we just need to deliver the energy very quickly in a very small area. I'm talking tens of milliseconds, up to a max of about 0.2 seconds.

[Anonymous No.1286560]

>>1286490
scour craigslist for free microwave. voila yw

[Anonymous No.1286639]

>http://www.instructables.com/id/Tutorial-Spot-Welder-for-Lithium-ion-18650-Battery/
this looks interesting but it lacks schematics

[Anonymous No.1286670]

>>1286490
Make a giant transformer using metal and wire. You can make a thick wire using multiple strands of smaller wire like 12AWG, at least 6-8 strands. The primary coil needs the same number of turns as how many volts your input will be. It should be at least 12AWG. Like 110v needs 110 turns. Then the secondary coil needs only a couple of turns, however many volts you want to spot weld with, like 2 or less volts. 1.8v is just about right. Your metal core can be anything ferrous like metal pipe, a few pieces of rebar, flat steel, old motor frame, etc. It can be an E-I shape, a torus, or a square.

https://www.youtube.com/watch?v=AbYNYXJe5Cc

That should be enough to get you low enough volts and high enough amps to spot weld with. Wear protection and be careful.

[Mr.T !LeoPard6uk No.1286680]

>>1286670
>The primary coil needs the same number of turns as how many volts your input will be. It should be at least 12AWG. Like 110v needs 110 turns.
>>1286670
>Your metal core can be anything ferrous like metal pipe, a few pieces of rebar, flat steel, old motor frame, etc. It can be an E-I shape, a torus, or a square.

That's very dangerous advice! If you saturate the magnetic core then primary winding will effectively become short circuit and hopefully trigger circuit breaker.

Number of turns depends on frequency, saturation flux density, cross-section area, voltage.

[Anonymous No.1286683]

>>1286680
Fuck off and be "bored" elsewhere faggot.

[Anonymous No.1286855]

>>1286670
thanks finally something I can do with my limited materials
>>1286680
>at least 12AWG
>110v needs 110 turns
I think he covered mostly everything

[Anonymous No.1287455]

3-4 car batteries. n a pin welding at one of the ends.

[Anonymous No.1287464]

>>1286680
Yes really. That's how I've been doing it. That's how MOTs are wound. They are literally designed to work "dirty" with eddy currents and shit. Which is why they vibrate if you don't get them solidly mounted.

>dangerous

All of this is dangerous, but if you have the voltage correct, like below 2 volts then you can short the leads out with your dick and it wouldn't do anything.

>will effectively become short circuit

I've only had that happen if there's no secondary being used and the core isn't designed correctly. Like taking the I bar off the E-I frame and trying to use it like an electromagnet with full wall power and big ass bridge rectifier.

PROTIP: don't turn the spot welder on until you have your electrodes properly placed on the work piece. Even then you use a momentary pushbutton switch.

>Mr.T

I thought you left years ago.

[Anonymous No.1287467]

>>1286500
>rapid pulses

Dont use SSR for this guys.

[Anonymous No.1287490]

>>1286490
>attach long copper rod to object
>wait until next lightning storm
>????????????
>Profit????????