BOSS LEVEL CUSTOM SPOT WELDER

Hey, rojitor, if I'm not mistaken... 3s vs 4s is actually not necessarily as important as mAh and C.... ie. a 4,000 mAh 120C 3s is a huge difference from a 1,200 mAh 30C 3s or even a 1,200 mAh 30C 4s..... if I'm not mistaken

On a separate note, I finally got around to disassembling my broken welder, and testing the MOSFETs... looks like all 6 are blown. The drain to source is constantly connected.

I'm debating on what FETs to get to replace these (also hoping that replacing them is all I need to do to fix this thing). If I'm not mistaken, these are the ones currently on the device, and bad price (well, except this is the legit manufacturer... not to say the ones on it are any bad) https://www.arrow.com/en/products/irf1404pbf/infineon-technologies-ag

But instead, I'm thinking about getting these: https://www.arrow.com/en/products/irfb7430pbf/infineon-technologies-ag

A little pricier, but seems like close to double the specs. Can also order Chinese versions dirt cheap on ebay... but I think I'll stick with arrow... free overnight shipping.

Motors need wats... it is a fact that v×amps=wats so you can achieve similar performance with lower voltage increasing amperage but that's not an exact science as rpm needs indeed voltage and the wheel diameter enters in the equation.
For the welds... voltage is also something to mind. My lipos are nanotech. Very nice C discharge but the machine seems to need more voltage for copper. Even at full power 3s has no effect at all on copper. While 4s at low time flux makes effect inmediately. At least with this machine is like that according to my tests and my chats with the boss.
Aulakiria tested cheap chinese fets with this machine and told me they are very easily damaged. If you replace them yourself you better use good ones. I can't believe you didn't find any cheap option to deliver it. I sent to korea a heavy box for 20 euros. Well... I guess it would be a great experience repairing it yourself.

Well, just ordered 8 of both. Tho definitely planning on using the IRFB7430PBF... they are actually the recommended MOFETs for this DIY arduino welder (http://www.instructables.com/id/DIY-Arduino-Battery-Spot-Welder/) which I plan on building soon (ordered 2 sets of the boards + aluminum... and the other parts from arrow the other day... minus the fets... ordered some chinese copies of the irfb7430 on ebay... thinking about making 1 with those, 1 with legit ones from arrow, and maybe comparing them)

Also thinking about building my own super-capacitor "power pack"... ie. a few high power capacitors in series (connected to an AC to DC power supply for charging them)... while they make some seriously powerful LIPOs now, with the right fets, and enough of them, should be able to build a pretty awesome power source for welders. Plus won't have to replace it often like you might with a LIPO, if used a lot.

rojitor, I think I worded things wrong, really was saying you need to give the C ratings too so people have a better reference, and understand it's not just voltage (or in terms of 3s and 4s). While I have done my best to forget everything I learned at school... I technically do have an EE/CoE degree... so definitely aware of ohms law, and watts vs other values... etc. And my real point was, based on the huge range of C values (and mAh) in LIPOs... they can make a bigger difference than the voltage... not that voltage doesn't matter too.

Ye. We got lost in the explaining. No problem.

So Aulakiria said the IRFB7430's are really good FETs... just they aren't available where he is, which is why he used the IRF1404, so definitely giving them a try.

BTW, just bought a Hakko FR-300 all in one solder vacuum.... it's frocking amazing. Thought it was a little pricey at first (but other than some knockoff no name brand solder stations, this was the cheapest legit option), but when you get it, and feel it's weight and use it, it's pretty awesome. Plus there's a lot of solder to remove to get these FETs out, so really helpful.

I have many solders and the hakko supplied by Aulakiria has become my fav. It heats very fast. Maybe the solder Tip is not my first choice but I love it anyway.
The fets used on this machine are made in Korea and Taiwan. I guess the price could rise too much if he used other fets.
He wants the price to be affordable.
So...
Can you get better fets at a reasonable price?
All the fets are expensive in my country.

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/171951197612
Hella expensive. Even the chinese counterfeits are expensive.

First off, I got legit infineon tech IRFB7430PBF's from arrow.com, free overnight shipping, for $3.27 a piece.

Second, you can get cheap chinese ones off ebay, 10 for < $7 shipped: https://www.ebay.com/itm/10pcs-IRFB7430PBF-IRFB7430-HEXFET-Power-MOSFET-TO-220/172065909235?hash=item280fed69f3:g:KloAAOSwqrtWm57Q

I ordered the ebays ones just to mess around... might build one of those android spot welders with them, one with the real thing, and compare.

Second, I feel bad for you if the hakko knockoff you got with this welder is your best soldering iron. I got a legit Hakko FX-951 (with T15 tips), and also have the Hakko FM2032 Micro soldering handpiece (takes T30 tips)... as well as just got the Hakko FR-300 desoldering gun.

The knockoff Hakko handpiece that came with the welder (well as an upgrade) works... and you can get the dirt cheap knockoff tips (so could replace your tip really often and cost next to nothing).... BUT... it doesn't even compare to the legit ones I have.

On a similar note, I've been wanting a hot air rework gun for a while... this time not going with an expensive name brand... just no need for that... was about to order the insanely inexpensive, yet according to reviews does it's job 858D (ie. $33 for one shipped: http://r.ebay.com/EzZvcO ) .... but decided to go with the HFS 959D through amazon (http://a.co/h2KWXZ1) .... at $50 with free prime delivery, I get it in 2 days, if any problems super easy to return, apparently HFS backs it with a 1 year warranty and actually has really good customer service... and really the reason for getting the 'upgrade'... this one has a PID heating algorithm. I figure all that is worth the extra $17... I mean $50 for a fully functional hot air rework station... if I only knew about this a while ago, would have made things so much easier.

Edit: And on a side note... arrow.com is frocking insane. I ordered $25 worth of random small parts (something like 40 parts), with free overnight shipping. First off, every different part came in it's own almost 12"x12" antistatic bag (and the small ones came in a second smaller bag inside of that one). On top of that, that $25 order came as 4 separate boxes (didn't check all of them, but at least a few were from different locations, I would assume all were)... 3 of them were from the US... the 4th one I just got today (took 1 extra day).. from the Netherlands... guess what it contained?.... 3 x 1 uV 63v film capacitors.... total value/cost to me of these 3 shipped from the Netherlands (in a pretty damn large box for what an envelope would have done fine)... $0.52... yes 52 cents..... I almost feel bad, but I know why everytime I buy electronic components I at least try to get them from arrow

And on a completely different side note... trying my best to talk myself out of buying these: http://www.all-spec.com/Catalog/Hand-Power-Tools/Screwdrivers-Accessories/Screwdriver-Sets/32390-56114 ... for $100, a set that large of quality WIHA (let alone their ESD) stuff... damn that't insanely cheap. BUT, I technically already have multiple sets of Wiha screw drivers (given, not their 1000v esd)... as well as a set of Knippex pliers/cutters... but damn, literally 2 od those pliers would normally cost $100, easy (of course they have more than that from wiha on sale.. def getting a few things... but trying my best to not buy that... its soo freaking tempting, such an amazing price.. but I really don't need them.... though they will definitely last my lifetime, and then some)

Man, just did a little searching for some other batteries than the Sanyo 20700A's I've been using (using them for their high 30A discharge rates). Was looking for something with high capacity this time, while still having a decent amp rating. Seems like the Sanyo 3500 GA cells are the best option... but I can't find them, or anything close, for under $6 after shipping (for about 50-100). That just seems high.... What cells do you guys use for your packs? ... how much do they cost, and where do you get them?

Oh wow, great price.. sadly I bet the price would totally be ruined by shipping them to the US.... shipping alone might suck, BUT, shipping batteries are one of the biggest PITA, especially from out of country... migth get hit by customs fees or other crap too...

But I am jealous... wish I could find that in the US.

...OH man, they even have the 20700B at a good price: https://ru.nkon.nl/rechargeable/other/sanyo-ncr20700b-lithium-battery.html

I dunno how good or bad shipping fees are. Seems many american es members are buying from them.
Check also the cells of michal :

https://endless-sphere.com/forums/viewtopic.php?f=31&t=61608

Man, I feel like you're just teasing me with these amazing deals in EU....

At this rate looks like I'm going to continue buying these Bosch battery packs... already bough 4 boxes (of 2 batteries and a charger)... selling the chargers... finally found just he 2 batteries where it makes sense to get them. Well, tech after selling the charger, it's cheaper that way... but more of a hassle... was getting 2 battery packs and a charger, brand new sealed box, for $120 shipped, and selling the chargers for $20 (could get more probably, but this way it's quick, and people come all the way to me without complaining)... now I can get 2 batteries for $105 shipped. Either way, pretty much comes to exactly $5 a cell (but as I've said many times, at least with these current packs, I am not only making use of part of the original case "coolpack 2.0", I am also utilizing the copper plate that is currently laser welded to the batteries from the factory. Def a step up from your standard nickel, or prob more likely nickel plated steal, most tool companies use).

But, my next pack I want to 3d print my own holders, and do something like this: https://www.aliexpress.com/store/product/High-quality-18650-battery-holder-For-big-power-battery-pack-50A-100Ah-200Ah-Lower-price-is/623665_32837557299.html (check out the bottom pictures for the full setup)

I'm going to have 1 KG of 0.2 x 7mm nickel, and 1 KG of 0.2 x 27mm nickel... and I have a ton of different thickness/shapes of copper... BUT I'm pretty sure I'm gonna try with this new copper I just got... I got 16oz (0.0216" or 0.55mm) copper... 1" x 120" and 2" x 48" for now. And already got the knurled insert bits (like you see in the plastic holders in the above link... I have both brass and copper, thinking I'll go with copper, tho prob doesn't matter... and prob M4, tho have M3 and M5 as well).... and I think I'm gonna go with aluminum screws (might help a little over steel for conductivity... plus they are lighter... and inexpensive) plus got copper washers. Seems like a really sweet setup, where I don't need to weld the copper, but should be able to carry some serious amps through it... will spot weld the 0.2mm nickel to the batteries (prob using the 27mm to cover the series),and have it with the copper plate screwed down directly on top, pluse the copper washers to help keep the pressure across the whole top (might even try to find some extra wide copper washers).

I'll share my 3D model once I make it, and get the kinks ironed out.. in case anyone else wants to give the setup a try. And will see if there are any improvements i can make as I go... could be beneficial to utilize magnets... OR I could do something liek what the Bosch battery packs do.. both the bottom and top covers have a soft rubber like insulation layer that is pressed firm again the copper plate... which I assume not only helps imrpove contact between the copper and batteries, but also acts as a cushion in case the battery is dropped. Might work better than magnets, and cheaper... and have multiple benefits.

Those prices are without vat for non eu countries. We pay much more than that from their eu site https://www.nkon.nl/

Oh shit, guess you weren't just showing off, haha. I suppose i'll have to look into the expense of shipping (and any other fees that may occur) from EU to the US. Definitely a lot easier shipping batteries from within the states... generally just need to have those absurd "dangerous... battery" stickers on the box... and no tax if it's from out of state (tho with my luck, more than half the things I go to buy end up being in California).

Wish someone would chime in with a good US source... but so far looks like I gotta research those EU more. Either that, or just stick with these Sanyos 20700A's salvaged from Bosch 18v 6.3aH batteries... which are amazing with regards to Amps (30A a cell continuous.. and that's not a BS number)... but nothing special for their size when it comes to capacity (3,100mAh I believe). But, if I ran anything higher than a 2p (with 20s or 24s), I'd probably need more than a shunt mod to my 40A controller. (In fact, looking for a good controller to replace the stock one... one that can handle 24s and high amps... tho I don't mind performing upgrades myself if need be... just want a solid base to start)

Finally got around to doing a few test welds with my new welder. Bought the battery that is recommended on the spot welder page, Turnigy 5.0 40-50C 3S. TBH it seems kinda weak... but didn't wanna blow the welder on my second weld again with my other battery... so figure I would get this one, get enough welds in to feel safe, then move to the better battery. Anyway, considering I only got 2 welds in last time (well not even 2 really), not sure what exactly is "normal" when it comes to using the welder.....

First off, I'm trying to weld a test piece of PURE 0.2mm nickel onto an old 18650 (old, but clean, no rust or anything funky). Pretty much every weld, there is a spark, I thought with pure nickel it shouldn't spark?.... and I am sure this stuff is pure nickel (even pretty high purity at that, made some super green nickel acetate from this stuff (as well as did other tests before that to confirm it's real nickel).

Second, every time I weld, the electrode's wires kinda "jump"... I tried both electrodes I have... pretty much same thing with both.

And finally, as I said, seemed liek the battery was kinda weak... I fully charged it, and started at either 1ms or 1.5ms.. with "multi pulse" set to 1... and ramped it all the way up to 4.5 before I got anything close to a weld between the nickel and battery, and even at that, it wouldn't count as a good weld. I then changed the multi pulse to 2, and went from 3ms back up to 4.5. At 4.5 I was finally get OK welds, but still not consistent/great (tho only tried a few). Trying to take it easy this time, and wanted to confirm that everything sounded about right before I moved on with potentially stronger settings.

So again, to sum things up: using 0.2mm PURE nickel, and 5,000mAh 4-50C 3S lipo, fully charged. Testing on a "junk" 18650... about what settings do you think should work roughly?... and was the sparking and wire "jumping" perfectly normal?

edit: side note, finally found a cheap battery voltmeter that can handle up 20s (Sadly not higher, wanted one for up to 24s... apparently this one is 30-84v... even tho title says 4.5-120v)... more importantly, and what I mean by "finally found" (since there are tons of these), is that this one is 2 wire, it runs off the voltage it's testing (I was only finding ones that required a separate lower voltage to power), and is only $1.57 shipped: https://www.aliexpress.com/store/product/0-36-DC4-5-120V-Car-LED-Display-Digital-Voltmeter-Volt-Meter-Automobile-Motorcycle-Voltage-Gauge/833031_32761590308.html

edit 2: Found some even better voltage meters that don't require a separate power supply... AND even one cray one that measures soo much more. I made a post with a list of them, I ordered all 3 of the hidance ones already: https://endless-sphere.com/forums/viewtopic.php?f=14&t=91501

rojitor, where you at?... been waiting for your response before I continued spot welding... wanna make sure nothing is wrong. Also, you should check in on the kWeld thread, there's been a lot of talk about getting copper welding to work... seems like you're one of the few to succeed, they could probably use some advice. Another thing brought up there was the benefit of using a slot between weld points... def a useful technique... I'm trying to find the best/easiest way to do so with thin nickel (and maybe copper) without indenting/warping the metal around it... so far a dremel is all I can think of, but hoping to find something a bit easier, like a form of pliers or hole punch... sadly as far as I've tried, tin snips cause warping, so they're not ideal.

BTW, got my 2 DIY android spot welder boards (actually 4 boards, each device is 2 boards)... now I'm debating on using my legit IRFB7430's on that, or on my BOSS fix. I also have both legit and copies of the IRF4110... they look almost identical, tho really close inspection can tell minor differences... I wonder if they will function the same or not... can't say I have the right tools to do a real comparison. I have a BUNCH of IRF7430's comings from ebay/aliexpress (I think it's safe to say they won't be legit ones.... but I suppose you never know)... since I wanted to do a comparison of legit ones and copies... that's why I might use them on the DIY spot welder (plus it's an 8 FET device, not 6.. so hoping it might be able to handle a bit more than the BOSS). Sadly, still waiting on the non-legit IRFB7430's to arrive.

On another side note... I've been looking into a DIY soldering project... I was watching a video about a guy who wanted a JBC welder (one of the high power ones), but since their price is soo high, decided to buy a legit handle and tips (which are very reasonably priced considering their quality)... the handle and tips already contain "what matters" for the most part, the temp sensing, and heater... so he went and built his own station that basically functioned as good as the real thing. He offered his designs as well, BUT also pointed out there there is a much more complex (read, harder to build... but more functional) DIY station that's been around for some time, and has a LOT more features. The UniSolder 5.2 (Universal Soldering controller, http://dangerousprototypes.com/forum/viewtopic.php?f=56&t=7218).... this this is pretty amazing, though not exactly easy to build. But it can handle multiple elements at once (ie. can support JBC tweezers... among a ton of other brands). But with this kit, you'd not only be able to run practically any JBC handle of your choice (or another brand if you prefer), you can run other soldering devices like the tweezers (which the tweezers themselves don't cost much more than $100... but a legit JBC station that can run them usually is in the > $2k range). My hakko FX-951 is def not bad... but man, this setup sounds sweet. You can buy the pre-printed PCB relatively cheaply (abut $15 shipped)... but I'm gonna check out how much it costs to print your own (gonna check pcbway and maybe some others)... I'm jsut trying to figure out the spec I need to set when ordering, seems like it's pretty standard... but I'm not 100% sure about min track/spacing, min hole size, thickness, etc (again, my gut says the defaults prob fine.. but trying to get that confirmed). If I get some boards printed, will offer them to you guys at cost.

The electrodes wires jumping is normal. As a matter of fact that's how it should be. At least one of the wires must jump. The sparks with pure nickel....
There's a few reasons:
The nickel is not 99% pure. Even if it is not plated some are low quality. If you doubt about it make corrosion tests.
The tabs are not perfectly clean. Rub with alcohol or acetone bot tabs and 18650 contacts. If they are salvaged make sure there's no old nickel there.
The pressure is not right. There must be no gaps. Put your finger on the tips and make some pressure. Look at any of my videos and you will notice it. Not the first one...i was grabbing wrong the pen by then.


Also make sure the electrodes are clean. I usually have some sand paper on the table and i rub the copper points gently every few welds.
Side note: i bought some pure nickel from centain mf at aliexpress since it was pure i bought again and he sent me plated.... mwahaha, never trust blindly those sellers.

For nickel you don't need multi stage. X1 is enough. I wrote the times at the first post.
0.1 1.4ms
0.15 4ms
0.20 7ms
The machine works better if your lipo is fully charged and balanced but nickel does not require that much power. You should get decent welds even with the battery low.
Test with a cutter blade if you have some time. They are dirt cheap and the test is very useful. You can know the real power of your setup after a thorough blade test.
Well....no need to test it to the limit like me but you can make a thorough light test from 1.4 to 9ms

[youtube]voWpcxBbxoA[/youtube]

Heh... I bought nickel from 3 sellers on aliexpress.... oh wait... make that 1 seller... the other 2 sold me steel... AND even claimed that they neevr said it was pure nickel... even tho the title said "Pure Ni" or "Pure Nickel"... and the description said "Chemical composition: > 99.96% Nickel" ..... I was ready to flip out. You can make certain claims, or be ambiguous, etc... but when it repeatedly says pure nickel, and even give the chemical composition as that much nickel, then tell em "We never stated it was pure Nickel". Playing dumb like "we didn't know" etc... I can understand, but this one was just frocking insane.

Anyway, the 1 legit store (ANNpower... both https://annpower.aliexpress.com/store/623665 and https://www.aliexpress.com/store/212674), is where I got my 1 KG (luckily the other orders were small, 1-3 meters, <$10)... but ANNpower actually has a ton of different nickel products, BUT they VERY CLEARLY state when one is nickel vs nickel plated steel. Seems like that's one of the safer way's to buy the nickel... find a store that also sells nickel plated steel and clearly differentiates the two. And, as for this nickel being pure... it's pretty damn pure... made my nickel acetate from it, and it is a beautiful green. They also just added a nice copper product (and those battery holders + nickel plate + copper combo... pretty cool setup, but I'm running 20700 not 18650, so gonna try to make my own similar to theirs). Anyway, I can highly recommend them... they package nicely, have good communication... and are VERY clear what each product is. Just make sure you are getting one that is pure nickel, not nickel plated steel... they do have both as I said.

As for the other reasons... yeah.. most of them sound about right. Need to clean everything (was doing test run on bad battery... should have cleaned everything, but wasn't really thinking about that).

Thank you for confirming all that... the wire jumping was the one I really wanted to make sure was correct... I don't think I've noticed that in any videos before.

I'm about to make some spare electrodes... both for my new welders, and for this guy, with the 2 separate, to give more control. AND finally got a couple of foot switches yesterday... I can't believe the $2 shipped (actually one was slightly less, one was slightly more) are as nice as they ended up... solid metal, feel like good switches. Also got a 3rd one that was about $5, even nicer... but it's a 3 wire... I think it might actually not be a simple "ON/OFF" but a progressive switch (ie. sends signal of how far it is pressed, 0-100% of something). But that's just a guess. Either way, glad to have the option to use a foot switch... just need to add some extended wire to them (they come with like 6 inches of wire... but for the price, who cares)

Got my broken BOSS welder all in pieces, used new connectors and copper wire (got that all setup)... just deciding what FETs to use.. possibly waiting for the other IRFB7430's to arrive. Might build one of the other welders in the meantime.

BTW, so nice having a functional FET around. Since ALL of my FETs I tested failed, I was slightly concerned I was doing something wrong. But no, they are indeed all bad, and the new FETs work as they should.

Thanks on those times... tho as we previosuly covered... the C rating is going to change theem quite a bit. I have 2 batteries for this, one 3s 4,000mAh with a really high 120C.... and now I also have the one recommended, the 5,000mAh 40-50C... which feels DRASTICALLY weaker due to the lower C, even with the higher mAh (I truly dislike the fact that you need to take mAh into account with C, for understanding the batteries power when welding... just so weird to have the aH's be relevant here).

Nickel is soft. You can weld with any lipo. Lee used crappy B grade for testing. It's just that the better the battery the better the performance. In worst case scenario you will have to charge it more often and rise flux times a little if the battery is not high quality.

I am almost done editing my last build. I did this battery under 100 euro enclosure included.
It is meant to be used on a sk8 but can be also suitable for ebikes.
Will upload shortly.

[youtube]yOnGAHu_odw[/youtube]