Author Topic: kWeld - "Next level" DIY battery spot welder  (Read 90545 times)

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Offline tatus1969

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #575 on: June 26, 2018, 09:59:28 pm »
Any news on stock update, is it going to happen on the end of June as planned or there might be delays?
The boards have been manufactured last week, production testing is planned for tomorrow. They appear to keep their schedule, but I think that I will receive the boards next Monday and not this week anymore (unless DHL is quick). The cable assembly firm was causing me headache right from the start (initially I gave this prio 2 because I expected a much shorter lead time for that. Still, my order was on ). Yesterday I learned that they still haven't received the 8AWG wire and it was *not* the fault of my overseas supplier. They are arranging an expensive courier now (at their expense), their internal production time will be one day. I have just talked with them, and they said that they will still be able to deliver by end of this week. The last non-stock components are the brass bus bars, they are finished and will ship today (domestic). Everything else is here and waiting, and I have helpers standing by to ship out all orders in two days at most. Fingers crossed, I'll keep you updated!
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Offline kulla

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #576 on: June 27, 2018, 06:56:10 am »
Sounds promising, fingers crossed.

 

Offline bluebird

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #577 on: June 27, 2018, 10:44:47 am »
Beginner here - I have a big question that I hope you all would be able to help me with:

I'm planning to weld up some 18650 cells for an e-bike I'll be building and I'm thinking of purchasing the kWeld to do the job for the following reasons:

- Quality and flexibility of the kWeld system
- 120V battery spot welders like the ones from Sunkko require at least a 40-amp circuit breaker; common US homes have a 15-amp circuit breaker for the 120V outlets - this would not work for me

What are my easiest (and perhaps also affordable) options for powering the kWeld system?

- I don't have any high-powered batteries laying around so it would seem wasteful if I get a high-C RC LiPo or car battery pack and charger just for the kWeld system
- It seems the kCap requires a high-amp power supply for charging; although I have a few sub 500w ATX PSUs and 3-amp lab power supplies laying around they don't seem to be suited for the job

Apologies for my lack of knowledge on this matter. Any help will be highly appreciated!
 

Offline tatus1969

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #578 on: June 28, 2018, 01:30:12 am »
What are my easiest (and perhaps also affordable) options for powering the kWeld system?
I would consider a decent 65AH car starter battery as the most affordable solution. The other two (that I am aware of) are the ones you mentioned, capacitor and Lipo.

It seems the kCap requires a high-amp power supply for charging; although I have a few sub 500w ATX PSUs and 3-amp lab power supplies laying around they don't seem to be suited for the job
The required amperage depends on how fast you want to go. If you have time to let the capacitor recharge after each few welds, then also one with lower amperage like 3A will work. Higher amperage just means higher productivity.
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Offline yngndrw

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #579 on: June 28, 2018, 09:44:48 am »
Really impressive project, I've just ordered a kWeld myself.

One question though, do you have any plans to open-source the firmware ? I mainly ask because I hate transflective LCDs and would like to switch it out with a nice OLED module.
 

Offline tatus1969

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #580 on: June 28, 2018, 07:30:22 pm »
Really impressive project, I've just ordered a kWeld myself.
Thanks :-)

One question though, do you have any plans to open-source the firmware ? I mainly ask because I hate transflective LCDs and would like to switch it out with a nice OLED module.
I don't like the display either, the decision for that back then was simplicity: been out there for decades, zero lines of code to implement and use.

Sorry, at the moment, I want to keep the source code closed to keep Chinese copiers away for as long as possible. But I can share the circuit if that helps.
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Offline yngndrw

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #581 on: June 28, 2018, 08:08:43 pm »
Fully appreciate the issue with cheap clones, they ruin things for everyone.

I don't think the circuit alone would help (Just need an SPI or I2C port really - From your earlier schematic it looks LCD RS, RW and E are all members of SPI port 2 which is ideal) as the OLED displays tend to be full graphical modules rather than having a text-based controller, so major code changes would be required.

I was looking at using something like this: (It's 4 wire SPI, but chip select isn't needed - There are some cheaper monochrome versions)
https://www.adafruit.com/product/1431
 

Offline tatus1969

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #582 on: June 29, 2018, 06:18:40 am »
From your earlier schematic it looks LCD RS, RW and E are all members of SPI port 2 which is ideal)
Did a quick check - bad luck, none of the SPI lines are available (current design uses STM32F103C6T6A).
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Offline yngndrw

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #583 on: June 29, 2018, 08:17:36 am »
Oh sorry, I must have been looking at the wrong datasheet.

That's a shame. Are there any I2C lines available ? I believe it can be either PB6/7 or PB8/9 for that microcontroller ?

If so, there are a couple of monochrome OLED displays which support I2C:
https://www.adafruit.com/product/931
https://www.adafruit.com/product/938

I've used the smaller one before and it's a really nice display, but the bigger one would allow a larger font and would therefore be more readable. I2C is a little slow for graphical displays, but I have had some success increasing the clock rate with these.

I guess failing this, it would be possible to output the current status (I.e. Everything that's displayed on the LCD and more) via the firmware update serial port and display that with a second microcontroller who's responsibility is just to drive the graphical display - That would also enable upgrades for existing customers.
 

Offline tatus1969

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #584 on: June 29, 2018, 06:48:49 pm »
That's a shame. Are there any I2C lines available ? I believe it can be either PB6/7 or PB8/9 for that microcontroller ?
Interestingly, PB6/7 is available at the red MicroMatch connector along with +3V3 / GND :-)
But you can always bit-bang SPI, that'll still be faster than I2C. A side remark: I don't want to give you false hopes of a firmware change. I have several other projects on my desk, and can't justify spending time on a working product like this.

I guess failing this, it would be possible to output the current status (I.e. Everything that's displayed on the LCD and more) via the firmware update serial port and display that with a second microcontroller who's responsibility is just to drive the graphical display - That would also enable upgrades for existing customers.
That would be a lot of work, because doing it right would mean to present control to the full functionality on this interface.
« Last Edit: June 30, 2018, 07:19:54 pm by tatus1969 »
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Offline yngndrw

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #585 on: June 29, 2018, 07:29:54 pm »
Which option, the first ?

Well assuming you're still using the Newhaven NHD-0108HZ-FSW-GBW display which uses the ST7066U controller, you have to emulate 8 characters and 4 extra segments. There are 11 instructions to implement and two blocks of memory. (DDRAM and CGRAM - 80 bytes and 64 bytes respectively) Assuming that you're not using the 4 extra segments or any of the custom character stuff, this can be simplified substantially.

Having said that, the second option with a second microcontroller which displays data from the firmware update serial port seems like a better option to me, as it allows for the new UI to better match the capabilities of the graphical display and outputting data via serial could also be useful for other applications like logging on a computer.

Datasheets I've been working from:
https://www.newhavendisplay.com/specs/NHD-0108HZ-FSW-GBW.pdf
https://www.newhavendisplay.com/specs/NHD-0108HZ-FSW-GBW.pdf
 

Offline tatus1969

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #586 on: June 30, 2018, 07:25:28 pm »
Which option, the first ?
The second. To add a graphic LCD and then just copy the information (8 characters of text) onto that would not make much sense in my opinion. I would want to actually use the bigger screen area to display more information, make the menu more intutitive, and others.

Well assuming you're still using the Newhaven NHD-0108HZ-FSW-GBW display [...] Assuming that you're not using the 4 extra segments or any of the custom character stuff, this can be simplified substantially.
Yes [...] no :-)
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Offline yngndrw

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #587 on: July 01, 2018, 01:40:13 am »
Sorry I didn't see your edit as I was writing my response.

If the hardware I2C port is available then that is the best option, far less impact on any existing timing code that you have as well compared to bitbanging. I've used these displays with I2C at 1Mbit/sec in the past then they performed fine, even when doing high frame-rate animation.

Fully appreciate the queue of existing work you have, it was why I first asked about any plans to open-source the firmware. At least now I know that suitable pins are already available on the current hardware, so it's at least possible.
 

Offline tatus1969

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #588 on: July 15, 2018, 04:31:30 am »
I just got the message from my cable assembly firm yesterday, that they will be delivering early next week. Here are a few pictures from their work. This is what customers having ordered after April will receive. You can notice the upgraded electrode system, which was partly because of the electrode system crimping problems that the previous version showed.





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Offline kulla

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #589 on: July 28, 2018, 07:17:43 pm »
Got mine yesterday, got to play with it already  >:D

I'm using 12V car battery for it, works like a charm.
 

Offline tatus1969

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #590 on: July 29, 2018, 06:16:10 pm »
Just saw that Dave has been opening his that I had sent him to his mailbag :-)
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Online tautech

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #591 on: July 30, 2018, 07:56:54 pm »
Just saw that Dave has been opening his that I had sent him to his mailbag :-)
Seems he was most impressed.  :)

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Offline anishkgt

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #592 on: July 30, 2018, 08:10:08 pm »
Beginner here - I have a big question that I hope you all would be able to help me with:

I'm planning to weld up some 18650 cells for an e-bike I'll be building and I'm thinking of purchasing the kWeld to do the job for the following reasons:

- Quality and flexibility of the kWeld system
- 120V battery spot welders like the ones from Sunkko require at least a 40-amp circuit breaker; common US homes have a 15-amp circuit breaker for the 120V outlets - this would not work for me

What are my easiest (and perhaps also affordable) options for powering the kWeld system?

- I don't have any high-powered batteries laying around so it would seem wasteful if I get a high-C RC LiPo or car battery pack and charger just for the kWeld system
- It seems the kCap requires a high-amp power supply for charging; although I have a few sub 500w ATX PSUs and 3-amp lab power supplies laying around they don't seem to be suited for the job

Apologies for my lack of knowledge on this matter. Any help will be highly appreciated!
There are quite a few reliable  replacement boards on eBay for those sunkko spot welders. I sell one of them as well. Fusing wouldn’t be a problem either. After 100s of Welds mine seem to be holding up. Here it is https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F282825618948


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Offline Cannikin

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #593 on: August 08, 2018, 06:50:32 am »
Hey guys, I just ordered a kWeld myself! I'm looking to CNC the case based on the DXF file from the site. I've converted the DXF to SVG so that I can then convert it into gcode for my CNC machine. However, after the conversion, the parts are tiny—the base of the case is about 1" square!

Can someone who has either the case itself, or the kWeld, give me some measurements so I know how to scale this thing? If you could give me the exact length/width of the case base, or the center-to-center distance between the mounting holes in the kWeld itself, that would let me scale this thing to the proper size (see attached image). (I'm assuming that the mounting holes on the kWeld line up with the 4 holes in the base of the case, if not please correct me!)

Thanks for any help!

 

Offline smgvbest

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #594 on: August 08, 2018, 06:20:52 pm »
This happens allot.  scale it for inch to mm or mm to inch(i forget which)   should do the trick
The DFX is in mm, 
A=94.8mm
B=104.1mm



Edit: Fixed a dyslexic moment there
« Last Edit: August 08, 2018, 06:23:17 pm by smgvbest »
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Offline Cannikin

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #595 on: August 09, 2018, 03:00:39 am »
This happens allot.  scale it for inch to mm or mm to inch(i forget which)   should do the trick
The DFX is in mm, 
A=94.8mm
B=104.1mm

Thank you very much!
 

Offline rx8pilot

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #596 on: August 09, 2018, 03:44:17 am »
I want to order one of these. There are are few toys on my wish list that need to come first, but this looks like a pretty cool way to catch something on fire.  :-+
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Offline tatus1969

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #597 on: August 09, 2018, 07:16:13 am »
I want to order one of these. There are are few toys on my wish list that need to come first, but this looks like a pretty cool way to catch something on fire.  :-+
I've finally managed create "permanent" stock --> https://www.keenlab.de/index.php/product-category/kspot-welder-kit/
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Offline netmonk

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #598 on: August 25, 2018, 07:42:51 pm »
Hello,
May be a stupid question, why not use XT60 input connector ? most of lipo are coming with such interface.
 

Offline tatus1969

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Re: kWeld - "Next level" DIY battery spot welder
« Reply #599 on: August 25, 2018, 09:48:01 pm »
Hello,
May be a stupid question, why not use XT60 input connector ? most of lipo are coming with such interface.
That is because the welder draws 1400A from the battery  8) Only short pulses, but every micro ohm ESR counts.
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