kWeld - "Next level" DIY battery spot welder

Batteries, Chargers, and Battery Management Systems.
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Re: kWeld - "Next level" DIY battery spot welder

Post by tatus1969 » Oct 19, 2017 5:18 am

The Lightning Stalker wrote:I've been thinking about weather an AVR would be capable of something like this. The ADC is nowhere near as fast (15kHz vs. 1MHz) and slightly lower resolution (10-bit vs. 12-bit) and there's only 1 instead of 2, but I'm wondering if all that horsepower is really needed. What are your thoughts on this?
The algorithm needs three ADC channels, it needs to slice the pulse duration into small pieces, and to measure the instantaneous weld power at a high rate. 15kHz is not even close to what is required, and the AVR will also not be able to do all the calculations quick enough. (I need roughly 20MIPS, and i have implemented it without using floating point).

The minimum pulse duration is currently 40us, and that is already almost too long to weld thing wires as you can see in some posts above.
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Re: kWeld - "Next level" DIY battery spot welder

Post by The Lightning Stalker » Oct 19, 2017 9:23 am

tatus1969 wrote:The algorithm needs three ADC channels, it needs to slice the pulse duration into small pieces, and to measure the instantaneous weld power at a high rate. 15kHz is not even close to what is required, and the AVR will also not be able to do all the calculations quick enough. (I need roughly 20MIPS, and i have implemented it without using floating point).

The minimum pulse duration is currently 40us, and that is already almost too long to weld thing wires as you can see in some posts above.
Ok thanks I was going by the 30J test in the video. It was showing t=20ms, unless I misinterpreted or you are talking about even lower energies and lower resistance than was shown.

I do want to get into STM32 eventually at some point, but there is a bit of a learning curve.

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Re: kWeld - "Next level" DIY battery spot welder

Post by cycborg » Oct 31, 2017 10:45 am

Interested in updates on this.

tatus1969, will you be doing another round of sales?

First-round users, any feedback?

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Re: kWeld - "Next level" DIY battery spot welder

Post by The Lightning Stalker » Oct 31, 2017 8:47 pm

^^ Indeed I am eager to get one of these in my hands, even if it is just a pile of parts to be thrown into the reflow oven.

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Re: kWeld - "Next level" DIY battery spot welder

Post by tatus1969 » Nov 01, 2017 5:40 am

I am busy sourcing everything, and almost completed. The last open thing is the assembled circuit boards themselves, and I have just received an email with lead time and price, and a few remaining open topics. My estimate is that I can deliver within 4-5 weeks from today, and I will open pre-orders on my website by this weekend. All preorder customers will be offered a 10% discount.
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Re: kWeld - "Next level" DIY battery spot welder

Post by tatus1969 » Nov 01, 2017 5:42 am

The Lightning Stalker wrote:^^ Indeed I am eager to get one of these in my hands, even if it is just a pile of parts to be thrown into the reflow oven.
I won't have bare PCBs in stock, as I decided to keep the firmware closed source to prevent chi* copying as long as possible. And that would mean to ship preprogrammed microcontrollers. If there is considerable interest, I can do that, but so far I don't get many requests from this direction.
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Re: kWeld - "Next level" DIY battery spot welder

Post by tatus1969 » Nov 03, 2017 1:25 pm

I am happy to announce that the next batch of kWeld is in production. I accept pre-orders through my shop: https://www.kicksurfer.de/index.php/pro ... elder-kit/ All pre-order products are on sale with a 10% discount until Nov 30!

New major features in revision 3:
• replaceable electrode system with minimum assembly effort
• extended input voltage range from 4V to 30V allowing the use of ultracapacitors without an auxiliary power supply
• improved protection against inductive kickback of both power switch and voltage regulator, tested to survive currents in excess of 2500A
• enhanced user interface featuring a rotary encoder with push button

Cheers
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Re: kWeld - "Next level" DIY battery spot welder

Post by tatus1969 » Nov 03, 2017 2:07 pm

Merlin wrote:so 6S Lipo isnt a problem anymore?
Still the current limit is at 2000A, it all depends on the overall ohmic resistance. If the battery is very low impedance, then you may still exceed that. More voltage is not necessarily more better in this case. I am working on a supercapacitor based power supply, and that will only have 7.5V and it still delivers 1000A+.

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Re: kWeld - "Next level" DIY battery spot welder

Post by JumperJackFlash » Nov 04, 2017 6:25 pm

Thumbs up on your quality control testing. I already placed an order for your welder.

Do you think this welder will be able to weld together nickel tabs on lipo pouches?

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Re: kWeld - "Next level" DIY battery spot welder

Post by tatus1969 » Nov 05, 2017 7:56 am

JumperJackFlash wrote:Thumbs up on your quality control testing. I already placed an order for your welder.
Do you think this welder will be able to weld together nickel tabs on lipo pouches?
Thanks :-)
The tabs of these pouches are made from tinned copper, I am not sure if that would work. Copper needs a lot more energy to melt.
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Re: kWeld - "Next level" DIY battery spot welder

Post by progrock » Nov 06, 2017 8:56 am

I definitely like the idea of setting joules... seems very straight forward, and apparently very effective. Just got a BOSS welder, but considering ordering one of these as well... would be interesting to compare performance, especially considering they could both be tested on the same batteries.

I must say, the board has a super clean look to it... def a step above your average pcb prototype order with soldered on 1206 SMD parts. Is that just a "standard" 1.6mm thick PCB with 2oz copper? (I'm kinda thinking no, but not too familiar with pcb prototype builds)

I've seen you using both brass and aluminum bus bars... why not copper?

I'm also interested in the single pulse vs dual pulse differences. I suppose you may have proven, if you can do it right with one, why have two... but obviously the 2 pulse method has been pretty heavily used on most spot welders, what's the purpose in that?... and how does this circumvent that, and go back to using a single pulse? (By go back, I mean, if you look at the progression of DIY spot welders, you can find the extremely simple, almost purely capacitor(s) and mosfets, no microcontroller, which obv had a single pulse... then as people added micro controllers, it seemed like everyone was going with dual pulse).... I must say, at the very least, with my limited knowledge on this subject, if your method does work consistently (apparently it does) it's definitely much more straight forward, no need to twiddle around setting 2 different pulse widths, on top of a dwell time.

Anyway, I really gotta say, so far looks like you did an amazing job... I'm very interested to see how it progresses.. though I think I'm going to have to make an order to try this thing out myself (I'll do my best to make a fair comparison between yours and the BOSS welder I already have... I think the 2 of them are a perfect comparison to show the benefits of your design over what's come to be a more standard design lately)

TBH, I really want to be able to spot weld copper plates (0.1mm thick copper to be precise), given I'd likely nickel plate the copper first, but I would really love to have a spot welder that I knew was capable of welding 0.1 bare copper straight to batteries, without concern of breaking the welder. After researching a handful of different designs, I've been considering attempting to build my own. My first big decision tho, is whether to use capacitors or just a lipo battery to power it. It seems like the new LIPO batteries can have some incredibly high discharge rates... on the other hand, with a bank of large capacitors (or even just some huge >1F super capacitors) and enough quality mosfets, you should be able to get whatever amount of power your could need. Do the first decision would be whether to just go with a LIPO or to go with capacitors... then if you were to go with capacitors, would it make more sense to go with a bank of somewhat large capacitors (as I've seen in a few different builds)... or would it be better to have 1 (maybe 2) huge super capacitors to do the job. I would think going with the super capacitors should theoretically make things a little simpler, but it seems like people usually go the other direction and use a bank of "semi-large" capacitors instead. I'm just wondering what the thought process is behind this.

Anyway, that was my plan... then I looked into your welder more.. and to be perfectly honest... your method of having the user simply set the joules, and tracking that, seems far superior to anything I would end up building... it's pretty impressive (tho sorta killed my motivation to try to make one myself, haha). But none the less... you've said that even this design likely won't be powerful enough to spot weld copper... are you planning on trying to build one that can?.... that's really my current end goal.

**edit: Almost forgot to ask, what mosfet's did you end up using for the beauty? (I can't fully make them out from the photos)

**edit2: On a side note, to those of you mucking around with "shitty" (at least by comparison) 3d modeling applications.... go get Fusion360.... it's 100% free for hobby use, it's incredibly powerful and intuitive (and can do a lot more than just create STL files)... not to mention it's cloud based. From my experience, nothing else I have used even comes close to comparing to it. Took a little while to get decent at it (tho there are so many instructional videos, and with just the basics you can do a lot).... and so worth learning. If the current case ends up being inadequate, I'll mock up a design in Fusion360, utilizing parameters for pretty much every measurement, so it would be next to trivial to make almost any size adjustments in the future.

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Re: kWeld - "Next level" DIY battery spot welder

Post by tatus1969 » Nov 07, 2017 3:09 am

progrock wrote: I definitely like the idea of setting joules... seems very straight forward, and apparently very effective. Just got a BOSS welder, but considering ordering one of these as well... would be interesting to compare performance, especially considering they could both be tested on the same batteries.
Sounds great, I am open to that!
progrock wrote: I must say, the board has a super clean look to it... def a step above your average pcb prototype order with soldered on 1206 SMD parts. Is that just a "standard" 1.6mm thick PCB with 2oz copper? (I'm kinda thinking no, but not too familiar with pcb prototype builds)
Thanks. The first boards were hand soldered, but mass production is done with proper industrial machines. The board is just 1oz, the bus bar design perfectly allows that even at 2800A.
progrock wrote: I've seen you using both brass and aluminum bus bars... why not copper?
Brass is easier to CNC machine. And I was afraid of copper oxidation, although I have been told that it would be electrically conductive. If production volumes go up further, then I will switch to proper tin or silver plated copper bus bars.
progrock wrote: I'm also interested in the single pulse vs dual pulse differences. I suppose you may have proven, if you can do it right with one, why have two... but obviously the 2 pulse method has been pretty heavily used on most spot welders, what's the purpose in that?... and how does this circumvent that, and go back to using a single pulse? (By go back, I mean, if you look at the progression of DIY spot welders, you can find the extremely simple, almost purely capacitor(s) and mosfets, no microcontroller, which obv had a single pulse... then as people added micro controllers, it seemed like everyone was going with dual pulse).... I must say, at the very least, with my limited knowledge on this subject, if your method does work consistently (apparently it does) it's definitely much more straight forward, no need to twiddle around setting 2 different pulse widths, on top of a dwell time.
As long as you only use constant pulse durations, you need two pulses. My approach requires precise measurement of voltages and currents, a calibratioon method, and the computation loop that accumulates energy is quite complex and requires a decent microcontroller with fast ADC's. The typical Arduinos aren't up to this task. For me, the energy approach seemed more logical, and I just seem to be the first having done it. As the welder cannot control the current, it is not appropriate to use a constant time when your material is not "constant".
progrock wrote: Anyway, I really gotta say, so far looks like you did an amazing job... I'm very interested to see how it progresses.. though I think I'm going to have to make an order to try this thing out myself (I'll do my best to make a fair comparison between yours and the BOSS welder I already have... I think the 2 of them are a perfect comparison to show the benefits of your design over what's come to be a more standard design lately)
Thanks, you should be quick because I appear to be running out of stock again already.
progrock wrote: TBH, I really want to be able to spot weld copper plates (0.1mm thick copper to be precise), given I'd likely nickel plate the copper first, but I would really love to have a spot welder that I knew was capable of welding 0.1 bare copper straight to batteries, without concern of breaking the welder. After researching a handful of different designs, I've been considering attempting to build my own. My first big decision tho, is whether to use capacitors or just a lipo battery to power it. It seems like the new LIPO batteries can have some incredibly high discharge rates... on the other hand, with a bank of large capacitors (or even just some huge >1F super capacitors) and enough quality mosfets, you should be able to get whatever amount of power your could need. Do the first decision would be whether to just go with a LIPO or to go with capacitors... then if you were to go with capacitors, would it make more sense to go with a bank of somewhat large capacitors (as I've seen in a few different builds)... or would it be better to have 1 (maybe 2) huge super capacitors to do the job. I would think going with the super capacitors should theoretically make things a little simpler, but it seems like people usually go the other direction and use a bank of "semi-large" capacitors instead. I'm just wondering what the thought process is behind this.

Anyway, that was my plan... then I looked into your welder more.. and to be perfectly honest... your method of having the user simply set the joules, and tracking that, seems far superior to anything I would end up building... it's pretty impressive (tho sorta killed my motivation to try to make one myself, haha). But none the less... you've said that even this design likely won't be powerful enough to spot weld copper... are you planning on trying to build one that can?.... that's really my current end goal.
Sorry for that 8) I think the problem with copper sheets is the high conductivity of this metal. It is hard to create heat. I made a little research, welders for this purpose tend to pump tens of thousands of amperes through the material. My welder goes up to 2000A before protecting itself. I have unsuccessfully tested welding copper with 1400A only, maybe I'll give it another try at that current level. I use two 3S Lipos in parallel to reach this current. I think a 3S BCAP3000 supercapacitor would also be able to deliver this current level. If you directly short circuit them, you'd get around 10,000A.
progrock wrote: **edit: Almost forgot to ask, what mosfet's did you end up using for the beauty? (I can't fully make them out from the photos)
6x FDB0105N407L. Quite expensive, but really necessary for 2000A and the huge inductive kickback that you get in a welder.
progrock wrote: **edit2: On a side note, to those of you mucking around with "shitty" (at least by comparison) 3d modeling applications.... go get Fusion360.... it's 100% free for hobby use, it's incredibly powerful and intuitive (and can do a lot more than just create STL files)... not to mention it's cloud based. From my experience, nothing else I have used even comes close to comparing to it. Took a little while to get decent at it (tho there are so many instructional videos, and with just the basics you can do a lot).... and so worth learning. If the current case ends up being inadequate, I'll mock up a design in Fusion360, utilizing parameters for pretty much every measurement, so it would be next to trivial to make almost any size adjustments in the future.
Thanks for the tip. Hmm, I don't like cloud-anything. I am almost happy with Sketchup. The only drawback of this tool is that it is more moulding than constructing. If you cut off a bit too much, then you have to glue more material to your part, and start over.
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Re: kWeld - "Next level" DIY battery spot welder

Post by progrock » Nov 07, 2017 5:41 am

Thank you for such a complete reply... thought I had made my usual mistake of going on for too long, where more than half of my questions get ignored.

Firstly, I already preordered (almost didn't... I know I technically don't need another welder... and after shipping, and converting from USD on paypal.. I think it came to something like $225... and as per my usual overbuying tools, I even ordered everything I need to build 2 of these welders as well: http://www.instructables.com/id/DIY-Ard ... ot-Welder/ ...so I might have one hell of a comparison review coming once I have all 3 in my hands to try). I will say, if you want to make a cheap welder that's a step up from just capacitors or a LIPO and some mosfets... that DIY Arduino spot welder is probably the cheapest one you could get that's controlled by a microprocessor and does 2 pulses, and appears to be solid/simple enough to get the job done many times without breaking. Of course I'll be able to back that statement more when I do the comparison.

TBH, I ordered yours for 2 reasons (neither being necessity)... reason 1, as far as I can tell, yours appears to be the best one in it's class. And reason 2, even if I build a custom one similar to the popular designs, tho ideally more powerful, I don't believe I'd be able to accomplish what you did here.

I also just saw your "power supply" build on the previous page... looks pretty cool... actually VERY close to what I was considering building. I think it's an awesome option/alternative to using LIPOs till they die and having to replace them... I'm sure many people will be interested. Tho I'm not sure if I would buy one, or build one myself.. I like building things myself, and been looking into essentially taking an AC to DC power supply, and hooking it up to a bank of capacitors (or even one super/ultra capacitor.... saw a 3,000F capacitor new on ebay for ~$40.... would need to check some more of it's specs... but at least from my basic math I would think something like that may be enough to use alone for a high power welder like this one. I'm still trying to figure out if there is any real benefit to using a bank of small capacitors vs just 1 large one.

I need to address the "I don't like cloud anything". First off, you are gonna be left behind if you refuse to utilize "the cloud".... it is the future of computing, in the very near future every home/work computer is simply going to be a Display, an input device, and an internet connection... All actually processing, running of applications, etc. will be done on the cloud. It will make it so computers cost next to nothing, but will easily have 10,000 times (really any number can be put here, 10k is just to make a point) the processing power whenever they need it, and your files will all be accessible from every device that you use, anywhere. I'ts simply the obvious progression of the internet and personal/business computers. One major problem today is all the misuse of the term "cloud"... what it really boils down to is near infinite processing power and storage for you, however much, and whenever you need it, but only when you need it. In stead of every person having to spend a ton of money on a computer that they don't even utilize 1 percent of it's total ability (ie running at 100% usage of all processors and storage at all times), and even having multiple computers per person... the clouds is, and will be, a pool off this, that gets temporarily allocated to a person as the need it, and taken back when they aren't using it. There are so many benefits to this, from computers being insanely cheap, but seemingly performing with next to infinite power, to things like drastically reducing electronic waste over.

Anyway, end rant cloud rant, begin Fusion360 rant.....

But to clarify, what I mean by Fusion 360 being cloud based (which to today's standards it halfway is) just means that you create an account (again, free for all students and hobbyist), and every file you work on is stored within the cloud storage automatically. You can still save things locally, but everything you work on, and everything you add to a project is uploaded (and actually converted when it's not the native file type, since it supports pretty close to everything it possibly could). So, if you go to use Fusion360 on any other computer (yours or anyone else) and log into you username, all of your projects will immediately be available to you, as if you were using your home/work computer. The fact that the application is free (unless you are making significant money from it's use) is just incredible in the first place... it's really like 10 different, amazing, complex (but intuitive) applications merged into one fluid application... and besides the applications being free, all the benefits of it's cloud storage are also free. IMO, it's incredible that they have done things this way.... for students and hobbyists to be able to use/learn such a powerful application for free, it's truly amazing... and for those who get really good at it, there will be plenty of job opportunities for them (as well as opportunities to make their own product/company). And aside from all this, as you become more familiar with using the program you realize how well thought out and intuitive it is (autodesk has been in the game for a LONG time, and always one of the best, tho usually one of the most expensive out of reach options for anyone who was not a professional). I've tried tons of 3d modeling applications in the past.... never got anywhere with them... it's incredible how quickly I was able to pick up enough to build/model close to anything I have thought up/needed. I promise, if you have any free time, especially if you own a 3d printer (or have access to one, or any other type of CNC machine) it is so worth trying Fusion360... especially if you ever wanted to build a custom product of your own.

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Re: kWeld - "Next level" DIY battery spot welder

Post by progrock » Nov 07, 2017 6:13 am

Oh, I totally forgot... while I still would love to be able to weld some thin copper... I did see a somewhat cool idea to utilize nickel + copper (where you only weld the nickel).... check out these new battery holders: https://www.aliexpress.com/store/produc ... 57299.html

If you scroll down, you'll see in the photos they have some nickel and copper plates that are designed specifically to match with the holders.... sadly those plates are not yet for sale (they just added the battery holder a couple of days ago)... but the seller tells me that they will be adding the nickel and copper you see in the photos (and the nickel will be pure nickel, not nickel plated steel). I've already bought pure nickel from that seller, and am very happy with it, it's very good quality nickel.

Anyway, I think this is a really cool design. It lets you make use of your spot welder with the nickel plate and then lets you add large plates of copper to allow for much high amounts of current flow through the battery pack. Also, the design of the plastic battery holders and how the copper is added gives another MAJOR benefit... it allows the maker to build sections of 4 or 6 batteries individually, then connect them all later on (this would also give you the ability to potentially identify a single block of failing cells, making it pretty easy to remove/replace them, and putting the pack back together with relative ease.

Now, I've been using 20700's lately... but this battery holder/pack design has got me thinking. I;ve actually been using brass knurled insert nuts (also available as copper) very often in my personal 3d printed designs (I find it much easier usually than attempting to use regular hex nuts, especially compared to some of the semi-complex 'pocket/slot' designs some people use for hex nuts)... I think I'm going to try to work out some designs similar to this battery holder (reusing it's unique design ideas... and hopefully improving on them) and make some parametric battery holders where it would be easy to use any size cylinder battery (primarily 18650, 26650, 20700 and 21700... tho adjustable to other dimensions as well) and be able to setup whatever number of rows/columns, as well as whatever number of parallel cells. I'll share my designs on here and thingiverse... and will take any recommendations people have for improvements/variations.

If these designs work out, I'll likely have less need for welding copper in the first place (**tho, one major reason I want to weld copper is that I have some battery packs that I want to use that have copper laser welded on them, sadly 1-2 of the packs, while partially disassembling, had 1 of their copper tabs detach from 1 cell.... so I would really liek to be able to reattach those... it's 0.1mm thick copper, hoping it may be possible.)

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Re: kWeld - "Next level" DIY battery spot welder

Post by RobertC » Nov 07, 2017 6:45 am

nice post, a bit too verbose, as I tend to do..

As for "the cloud". well sure if you want to put your data in a public place and then hope for the best security wise, then, yah, ok. mostly I go for local hosting, I got 4 providers doing FTTH for less than $10/month each. Not sure why I should pay somebody for this "service"... So yeah, I got the four fibers coming in, and a mini-itx pc with a quad port SFP board and some GPON adapters, and then BOOM, done.

Most anything to do with lawyers/clients, doctors/patients. well, cloud is bad.. Do the basics in house, 1000 cpu for a compute job, sure, farm it out. but the baseline should be IN HOUSE.


totally off topic, sorry.

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Re: kWeld - "Next level" DIY battery spot welder

Post by progrock » Nov 07, 2017 5:22 pm

Haha, sorry, I do need to respond OT.... I had this discussion with my friend who is a lawyer about 2 years ago. She felt the same way, as did her boss, and they felt the only safe way to hold client docs was on USB flash drive. Makes sense... sorta... but neither her or her boss were very technical, so they didn't think to encrypt this flash drive... and guess what?... they've lost more than one of these flash drives... but they still thought the cloud was not a safe place to save their documents. As for the cloud... encryption is your friend... and for the paranoid type, my favorite is have a hidden double/second encryption... as in, you decrypt with one password, you get some junk data (photos of your favorite pet, or something)... decrypt with another you get your real data. The genius here is, your real data is nothing but a bunch of incomprehensible bits that there is no way to even prove is anything but junk without the second decryption method+password. **Yes I'm aware the NSA has the tendency of not telling people they have broken an encryption method previously thought to be impossible... but as methods get more and more advanced, there are plenty of encryption methods that are basically mathematically proven to be impossible to break unless you factor in a time variable that is approaching infinity. And for the time being, the "real" cloud today has provided us with access to virtually private servers where for as low as $5 a month you get full administrative control over a server at the OS level. But anyway, the thought of the cloud being too public and unsafe will be less and less shared among the public as understanding and use grows... I just don't see any other possible progression in the near future... it's the very obvious path for things to go, there are just too many clear benefits to this approach (chromebooks and thin clients might be just a little ahead of there time... but soon, and almost inevitable (IMO)... they will be the norm). Plus everything from medical science, to movie/music production is going to benefit greatly... where tasks that took days (or much longer) can take seconds with the processing power that will be at everyone's fingertips (and not just for the very few with huge budgets... but for students with practically no budget as well).

Sorta on topic, just received my parts for building the arduino based welder from the instructable I linked (well all the parts from arrow.com, which I prefer over mouser/newark/digikey), still need the pcb boards and a couple of minor things that will take a but longer, oh and allmost forgot, seeing how this stuff was so cheap, decided to give the chinese copies of FETs a try on this one, got something like 20 x IRFB7430's for 10... for a more critical item I'd have gotten real ones, but for these will try the knockoffs first, and if need be get real ones. My ~$25 order from arrow totally made me look like a nutcase, got it in 4 somewhat large boxes, arriving at the some time as 2 large mostly empty boxes from amazon... every 10 cent part individually wrapped in a 12"x12" or so anti static bag. For free overnight shipping and packaging, not sure if arrow actually made any money, haha. And I got enough parts to build 2 of those spot welders (plus about $10 for fets and $30-35 for other parts still on their way... about $70 total for 2 welders worth of parts, def an economical deal). Will be interesting to compare how this works against the BOSS spot welder and this kWeld beast.

I've also been looking for a cheap USB based oscilloscope... found some incredibly cheap USB digital logic analyzers (Saleae clones) that seem to work very well, but hoping to find something that can also analyze analog signals (going for as cheap as possible, that will still actually work... was very tempted to try out the bitscope micro... the device itself seems pretty sweet, but apparently the PC software has too many issues, which is disappointing). Anyone got any recommendations on something that'll work?

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Re: kWeld - "Next level" DIY battery spot welder

Post by Buk___ » Nov 07, 2017 6:30 pm

progrock wrote:but they still thought the cloud was not a safe place to save their documents.
Think carefully about cloud services! Take a look at the list of 111 cloud-based services that one very large, very successful, very buoyant, all-cloud company has shuttered in the last 12 years.

Many of those started life as services from small specialist companies that then sold out to Google who maintained those services for just long enough to squirrel away the client base and get them hooked on their other products before killing them.

Even if you can recover your data before they shut up shop; can you find anything else that will read their data formats?

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Re: kWeld - "Next level" DIY battery spot welder

Post by cycborg » Nov 07, 2017 8:54 pm

Granted, starting a new thread is super complicated, but I bet a mod could help you out if you ask politely.

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Re: kWeld - "Next level" DIY battery spot welder

Post by progrock » Nov 08, 2017 5:13 am

Haha, yes apologizes for the OT... entirely my fault... I will refrain commenting further, just wanted to make it clear to the people working on enclosure models for this, using applications that don't even begin to touch the incredible functionality, and intuitive interface that Fusion 360 has, and why it's worth checking out. But, I'll make up for the OT discussion (as well as give you guys a little more of a push to try out Fusion 360) by working out an enclosure model for this welder that will be parametric in nature.... so all the dimensions can be adjusted by simply changing numbers in a list of parameters. Hopefully will make it possible to not only adjust for any future changes in the design... but make it easy to customize to incorporate differences that may be unique per user (ie. maybe have a battery holder integrated, that can be adjusted to fit any size battery snugly). Not that there is anything wrong with the current design (seems OK, tho I have yet to print it, nor do I have the welder in hand yet to see how it fits).... but will hopefully get you guys to at least give Fusion360 a look at... as well as give people more options (when it comes to free things, it's never a bad thing to have more than 1 to choose from).

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Re: kWeld - "Next level" DIY battery spot welder

Post by tatus1969 » Nov 08, 2017 6:17 am

progrock wrote:Thank you for such a complete reply... thought I had made my usual mistake of going on for too long, where more than half of my questions get ignored.
Wouldn't that be impolite to someone showing interest?
progrock wrote: these welders as well: http://www.instructables.com/id/DIY-Ard ... ot-Welder/ ...so I might have one hell of a comparison review coming once I have all 3 in my hands to try). I will say, if you want to make a cheap welder that's a step up from just capacitors or a LIPO and some mosfets... that DIY Arduino spot welder is probably the cheapest one you could get that's controlled by a microprocessor and does 2 pulses, and appears to be solid/simple enough to get the job done many times without breaking. Of course I'll be able to back that statement more when I do the comparison.
I know that one as well. Would be interesting to see how robust they are, especially when going to heavier duties like 0.3mm nickel strips in combination with a beefy Lipo like the Turnigy nanotech that I recommend.All other weaker Lipos tend to start swelling very quickly, which is definitely not what you want them to do considering how dangerous they can become when getting damaged.
progrock wrote: I also just saw your "power supply" build on the previous page... looks pretty cool... actually VERY close to what I was considering building. I think it's an awesome option/alternative to using LIPOs till they die and having to replace them... I'm sure many people will be interested.
I hope so! When you want to build your own: what you need is a current limited supply capable of delivering 500W, better 700W. This is equivalent to heavy duty spot welding of 0.3mm nickel strips at 1 pulse per second. Of course it does not need to be able to deliver this for a long period, as welding is rather a burst action, and also the circuitry, cabling and electrodes will need cooling breaks, but I don't want limit the usability by forcing the user to wait for capacitor recharging all the time.
progrock wrote: Tho I'm not sure if I would buy one, or build one myself.. I like building things myself, and been looking into essentially taking an AC to DC power supply, and hooking it up to a bank of capacitors (or even one super/ultra capacitor...
If you are interested in just building as well: as there is no IP to protect in the charger circuit nor the capacitor bank, I plan to sell bare PCB's and have Digikey BOM lists as well as fully assembled and tested units.
progrock wrote: saw a 3,000F capacitor new on ebay for ~$40.... would need to check some more of it's specs... but at least from my basic math I would think something like that may be enough to use alone for a high power welder like this one. I'm still trying to figure out if there is any real benefit to using a bank of small capacitors vs just 1 large one.
You need enough voltage to be able to push enough current through cabling, electronics and the weld spot. 2.7V is not enough, 5.4 maybe with thicker cables. Therefore I will be going for 3S. The 3000F capacitors seem to be a bit oversized and too expensive in my opinion, I am going for BCAP0310 in a 3S2P configuration. They will need fan cooling though.
progrock wrote: I need to address the "I don't like cloud anything".
This is much about personal opinion and the felt need of confidentiality, nothing that I want to step into in this thread.
progrock wrote: working out an enclosure model for this welder that will be parametric in nature.... so all the dimensions can be adjusted by simply changing numbers in a list of parameters. Hopefully will make it possible to not only adjust for any future changes in the design... but make it easy to customize to incorporate differences that may be unique per user (ie. maybe have a battery holder integrated, that can be adjusted to fit any size battery snugly).
I appreciate this much, especially as it sounds that you want to make it public as well!
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Re: kWeld - "Next level" DIY battery spot welder

Post by progrock » Nov 08, 2017 8:14 am

I think it's safe to say any work I ever do with regards to 3D modeling and/or electronics is something I have no plans of ever making a cent off of, so the only reason I wouldn't release anything to the public would be simply out of embarrassment (as in I don't think it's good enough to even be used by anyone else, nor would I want my name attached to it, lol). But my point being, 3D printing (and 3D modeling, for that matter) is solely a hobby for me, as well as any work with electronics (one of these days I really want to make something worth printing a custom PCB for.... even more incredible would be making something that not only was worth making a custom PCB, but having one worth/capable of automated assembly... the latter may be more of a pipe dream that likely won't ever happen).

So... as long as I don't completely and utterly fail at it, would be more than happy to release any models I build for 3D printable enclosures for this thing (STLs as well as the files needed to edit the model). In the last few months I've been greatly improving my chops with Fusion360, and hopefully finally at a point where I can succeed in something like this, where I'd actually be proud of it. Didn't take long to be able to build basic components in F360, but been working at parametric modeling, as well as customizing designs to make them easy to 3D print, as well as fully functional when printed. This will be a perfect chance to test/improve those skills. And, as you may have guessed, I really love using Fusion360.... so I do my best to promote it's use. Which reminds me, I recently built (and used) a custom 3d model for removing the lockring from White Industries The ENO crankset... and been wanting to post that, as well as start a thread to see what other tools (concentrating on those unique one off tools for different bike parts that seem to always be insanely overpriced... but since it's the only one available, leaving the home mechanic is a shitty spot).

Anyway, back to being ON TOPIC.... with regards to a 3D model, while I can wait till I receive the welder... if I had the dimensions of everything, would be easy enough to start working on it before I have the welder in my hands. ALSO, if there's anything specific you think would be nice to have in an enclosure (or specific things I should worry about... ie. targeting cooling, maybe even a fan mount) please LMK. Ideally once I get a basic one done, there will be more suggestions/requests.. so that I'll be able to improve it over time. And if anyone's interested, I believe Fusion360 makes it really easy to collaborate on a project (another benefit of it's cloud capabilities), so if anyone else wants in, let me know... could be interesting (both beginners and experienced people with F360 are welcome, I'll be glad to help somone learn, and even happier to learn from someone more knowledgeable).

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Re: kWeld - "Next level" DIY battery spot welder

Post by tatus1969 » Nov 08, 2017 12:35 pm

progrock wrote:even more incredible would be making something that not only was worth making a custom PCB, but having one worth/capable of automated assembly... the latter may be more of a pipe dream that likely won't ever happen).
That can happen quicker than you think. Just read the beginning of this thread: http://www.eevblog.com/forum/projects/g ... pting-here
progrock wrote: if I had the dimensions of everything
Nothing easier like that, I have exported the entire welder construction and uploaded it here: https://www.kicksurfer.de/wp-content/up ... d-assy.zip. Some elements aren't accurate, but it should be enough to start. The dial knob is not modeled, you can take the required hole diameter from the STL files of my case.
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Re: kWeld - "Next level" DIY battery spot welder

Post by tatus1969 » Nov 08, 2017 3:50 pm

progrock wrote: if there's anything specific you think would be nice to have in an enclosure
Here are the requirements that I had set for my case:
- it must be able to hold the PCB in place against mechanical forces coming from the cables
- be printable with minimum material
- as few fastening screws as possible (I use DIN 7981 PH, l=9.5mm)
- hidden screws
- ability to receive adhesive feet
- a bit of elegance doesn't hurt

Especially the first two aren't met well for the top part. You can print it upside down and avoid lots of support material and have a nasty surface, or you can print it straight and have lots and lots of support material inside. It is constructed like that because it needs to hold down the PCB as you can see in the picture. Maybe you have a better idea to solve this.
Unbenannt.png
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Re: kWeld - "Next level" DIY battery spot welder

Post by JumperJackFlash » Nov 08, 2017 5:20 pm

Could you get the covers injection molded and produced in lots? I'd be happy to pay extra for a cover for my welder as would most of your potential customers (I believe :D ).

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