I am happy to announce that the next batch of kWeld is in production. I accept pre-orders through my shop. All pre-order products are on sale with a 10% discount until Nov 30.
Beware of the Deans connectors, they are often produced with poor tolerances and deliver a connection with high resistance, if the terminals of the plug and socket aren't exactly at the same offset angle and parallel along the mating conductor then the contact area can be very small (ie just one corner of the terminal). the circular xt60 / xt90 connectors are far more forgiving by design and much more reliable in practice.
I totally underestimated the demand, and ran out of stock by just pre-orders in less than a week. I plan another batch right after having received the current one. I'll inform again through the newsletter. But in order help me estimate the demand, I have just implemented an "inform me on availability" button for the sold out products that puts you on a waiting list when you click it.
Hello there, I'm wondering if you are the USA supplier of the Kweld complete unit. If you are, do you have some for sale? If not, can you direct me to the supplier?
Nice project. I notice that the screen is dimming during every firing. I think your PS cap. must be undersized. Are you sure you aren't getting close to having brown-out issues with the MCU? Have you captured the MCU voltage trace on a scope during firing to check? The last thing you would want is a MCU (or MOSFET) latch-up during firing. That would be exciting. :) Personally, I would be a lot more comfortable if the logic had it's own power supply but maybe all you need is a larger brown-out capacitor (E.g. maybe a super cap like dash cameras use now.)
Thanks, and good observation! What you see is the firmware switching off the LCD's backlight during pulse firing, in order to save power consumption and allow for a smaller holdup capacitor. The current one is calculated for at least 300 milliseconds - confirmed on the scope. There is a 3.3V linear regulator behind that capacitor, and the microprocessor continuously checks the capacitor voltage during firing and aborts at
I am afraid that I am currently out of stock, but I plan a larger batch for pre-order around Sept~Oct 2017. The unit has an undervoltage monitor that prevents pulse firing below ~10V input voltage. But the device is designed for use with any suitable power source, and this monitor is only to protect it from insufficient MOSFET gate drive voltage. I always recommend to use a Lipo watchdog that you attach to the balancer connector.
Very nice, I love the compactness of your design. The electronics handle the abuse quite well, though you can clearly see the battery bloat, if you skip from 0:00 to 2:00 minutes. How many of those batteries would you need for a reasonable lifetime?
I've alread tagged the batteries as not suitable, and ordered better ones from Turnigy: nano-tech 3S / 5Ah / 130C. Yes, that's 650A *rated*. A first test of ~100 pulses was very promising, there was absolutely no swell, and the batteries delivered more than 1400A. I'll post a new video showing them, hopefully today.
Impressive battery, if it proves to handle well in the long term then this would definitely have the edge over lead acid batteries. I am looking forward to the video showcasing it!
I'm a bit confused, when looking to buy, i see all these other add ons...what is needed to build 18650 battery packs? do i need the additional power supply with 12v input? do i need the supercapacitor module? nothing is explained.
Have a look at the online manuals which give detailed description, as well as the discussion forums at esk8 and endlesssphere mainly. As this is a self assembly kit you need to spend some effort to dig into. The simple answer is, the standard kWeld kit plus a Lipo or starter battery (again, models are listed online) is enough to start.
@@wearethewatt2950 Ok thanks, i already have a car booster pack that should work nicely...so just the base unit is all I need? along with the consumable supplies of course..
@@rickc2222 Car booster packs often have output protection and/or overrated Lipo cells, I don't recommend using them for kWeld as they might quickly fail (if they provide enough current first place).
great project ! please can you try some other welds other than battery tabs? for example for art or jewelry , that way you can have more customers (welding pieces of various metals together ,or even solid wires ). the industry expensive spot welders have dual pulse , maybe you can put that on your software too (first pulse "cleans" the metal , second pulse does the weld). i am waiting for the manual to see if i can built it myself and i will sure order one soon !
That's a very interesting idea! I'm not familiar with jewelry welding, and I googled a bit yesterday. It seems that TIG welders are commonly used there. I'm not sure how a resistance spot welder like this can be used there, and what materials / material combinations would be of interest. If you have an idea of what to try / show, I would be happy to receive suggestions for my next video. I know that all existing welders that claim to be someting use the double-pulse technique. They use pulses of constant length, and if contact resistance is too high somewhere the weld can easily fail otherwise. My welder uses a completely different approach, and so far I haven't found any other professional device that is doing it the same way: it measures the amount of energy that is created in the weld spot over time, and stops the pulse when the commanded value is reached. If there is more resistance somewhere, then the pulse duration is extended. This guarantees that the amount of energy that is used for welding is always constant. There will soon be quite a few people evaluating and testing this welder, and if it turns out that this strategy is not superior, then I will be happy to add a cleaning pulse. The system is prepared to allow firmware updates in the field, I will add a programmer in the shop very soon (it is already being produced). The cost for that will be 10€.
I've googled a bit, current and voltage seems to be suitable (80A 20V), I didn't understand yet how the arc is ignited. I'll definitely investigate this when there is time.
Cool; ordered a welding kit just now for spot welding aluminum sheet metal...might you have a recommendation for electrodes for aluminum? And just to be sure...you are saying Aluminum was spot welded, right:P I have a 709A battery welder with the one-handed electrodes for bare cell lithium tabs...we'll see how that works. I'm guessing the tips are just plain copper.
kWeld is designed to weld nickel or steel based tabs of up to 0.3mm. I have tried copper in the past, which doesn't work. Aluminium is between those in terms of thermal and electrical conductivity. I haven't tested that, it might or might not work.
Oh, I see...I thought your tests around 5:15 are on aluminum, or are they not? Aluminum can be spot welded, but it takes good control of the energy introduced; as it appears your machine can administer, and it helps to have one of the more non-conductive alloys. Yes copper is very difficult, especially with copper electrodes. The precise power needed is important so the aluminum does not vaporize, but a lot of power is needed to heat it well. I'm surprised you haven't tried this...aluminum spot welding is very lucrative.
...welding aluminum would not damage the welder, will it? Would it help to have a input source with a higher IR, like 300A max lipo's (this was my plan...with less efficient lipos it should be less likely to cause damage to the welder, no?)
PDTech BigBot no, these are Nickel tabs. But you're right, and there are a lot of other ideas to try out. Like welding car body stud welding, jewellry welding, welding fuse wires to batteries, using different electrode materials, electrode water cooling, etc. I just don't have enough time for that, as kWeld is only a part of my ongoing business and customer design projects are currently using up most of my time.
allright, I'll give it a shot when I get the welder. I see tungsten being used with success with aluminum so I bought a few of those electrodes. I think it "should" work...I see other aluminum spot welders described as single pulse captive types, which sounds about like what you have here.
The Ultimate test on the Cookie Tin. 50J The New Standard.
Great test
I am happy to announce that the next batch of kWeld is in production. I
accept pre-orders through my shop. All pre-order products are on sale
with a 10% discount until Nov 30.
new stock is coming, and I've just opened for pre-orders at the shop! --> www.keenlab.de/index.php/product-category/kspot-welder-kit/
Beware of the Deans connectors, they are often produced with poor tolerances and deliver a connection with high resistance, if the terminals of the plug and socket aren't exactly at the same offset angle and parallel along the mating conductor then the contact area can be very small (ie just one corner of the terminal). the circular xt60 / xt90 connectors are far more forgiving by design and much more reliable in practice.
I totally underestimated the demand, and ran out of stock by just pre-orders in less than a week. I plan another batch right after having received the current one. I'll inform again through the newsletter. But in order help me estimate the demand, I have just implemented an "inform me on availability" button for the sold out products that puts you on a waiting list when you click it.
Hello there,
I'm wondering if you are the USA supplier of the Kweld complete unit. If you are, do you have some for sale? If not, can you direct me to the supplier?
Nice project. I notice that the screen is dimming during every firing. I think your PS cap. must be undersized. Are you sure you aren't getting close to having brown-out issues with the MCU? Have you captured the MCU voltage trace on a scope during firing to check? The last thing you would want is a MCU (or MOSFET) latch-up during firing. That would be exciting. :) Personally, I would be a lot more comfortable if the logic had it's own power supply but maybe all you need is a larger brown-out capacitor (E.g. maybe a super cap like dash cameras use now.)
Thanks, and good observation!
What you see is the firmware switching off the LCD's backlight during
pulse firing, in order to save power consumption and allow for a smaller
holdup capacitor. The current one is calculated for at least 300
milliseconds - confirmed on the scope. There is a
3.3V linear regulator behind that capacitor, and the microprocessor
continuously checks the capacitor voltage during firing and aborts at
Hi, nice device, i want one :-). Did you check the battery voltage for not go down to 3V/ element ? because Lipo don't like that.
I am afraid that I am currently out of stock, but I plan a larger batch for pre-order around Sept~Oct 2017.
The unit has an undervoltage monitor that prevents pulse firing below ~10V input voltage. But the device is designed for use with any suitable power source, and this monitor is only to protect it from insufficient MOSFET gate drive voltage. I always recommend to use a Lipo watchdog that you attach to the balancer connector.
Geat. Thank-you.
Very nice, I love the compactness of your design.
The electronics handle the abuse quite well, though you can clearly see the battery bloat, if you skip from 0:00 to 2:00 minutes.
How many of those batteries would you need for a reasonable lifetime?
I've alread tagged the batteries as not suitable, and ordered better ones from Turnigy: nano-tech 3S / 5Ah / 130C. Yes, that's 650A *rated*. A first test of ~100 pulses was very promising, there was absolutely no swell, and the batteries delivered more than 1400A. I'll post a new video showing them, hopefully today.
Impressive battery, if it proves to handle well in the long term then this would definitely have the edge over lead acid batteries.
I am looking forward to the video showcasing it!
New video online showing some substantial improvements! ruclips.net/video/rQnODV4VQjU/видео.html
great
I would use lipo with xt90 connector
That will work, the cable diameter just fits. A user just confirmed that the temperature rise is okay.
I'm a bit confused, when looking to buy, i see all these other add ons...what is needed to build 18650 battery packs? do i need the additional power supply with 12v input? do i need the supercapacitor module? nothing is explained.
Have a look at the online manuals which give detailed description, as well as the discussion forums at esk8 and endlesssphere mainly. As this is a self assembly kit you need to spend some effort to dig into. The simple answer is, the standard kWeld kit plus a Lipo or starter battery (again, models are listed online) is enough to start.
@@wearethewatt2950 Ok thanks, i already have a car booster pack that should work nicely...so just the base unit is all I need? along with the consumable supplies of course..
@@rickc2222 Car booster packs often have output protection and/or overrated Lipo cells, I don't recommend using them for kWeld as they might quickly fail (if they provide enough current first place).
great project ! please can you try some other welds other than battery tabs? for example for art or jewelry , that way you can have more customers (welding pieces of various metals together ,or even solid wires ). the industry expensive spot welders have dual pulse , maybe you can put that on your software too (first pulse "cleans" the metal , second pulse does the weld).
i am waiting for the manual to see if i can built it myself and i will sure order one soon !
That's a very interesting idea! I'm not familiar with jewelry welding, and I googled a bit yesterday. It seems that TIG welders are commonly used there. I'm not sure how a resistance spot welder like this can be used there, and what materials / material combinations would be of interest. If you have an idea of what to try / show, I would be happy to receive suggestions for my next video.
I know that all existing welders that claim to be someting use the double-pulse technique. They use pulses of constant length, and if contact resistance is too high somewhere the weld can easily fail otherwise.
My welder uses a completely different approach, and so far I haven't found any other professional device that is doing it the same way: it measures the amount of energy that is created in the weld spot over time, and stops the pulse when the commanded value is reached. If there is more resistance somewhere, then the pulse duration is extended. This guarantees that the amount of energy that is used for welding is always constant.
There will soon be quite a few people evaluating and testing this welder, and if it turns out that this strategy is not superior, then I will be happy to add a cleaning pulse. The system is prepared to allow firmware updates in the field, I will add a programmer in the shop very soon (it is already being produced). The cost for that will be 10€.
i mean this welder : ruclips.net/video/d4G9zT9-gME/видео.html
maybe it uses high frequency , cause the wires are not thick..
I've googled a bit, current and voltage seems to be suitable (80A 20V), I didn't understand yet how the arc is ignited. I'll definitely investigate this when there is time.
Sole!!!! How do I buy one???????
webshop www.keenlab.de 🙂
it looks like this is currently sold out. do you have a wait list for a second run?
The next batch will be large enough to keep stock. I am about to open for pre-orders soon.
Cool; ordered a welding kit just now for spot welding aluminum sheet metal...might you have a recommendation for electrodes for aluminum? And just to be sure...you are saying Aluminum was spot welded, right:P I have a 709A battery welder with the one-handed electrodes for bare cell lithium tabs...we'll see how that works. I'm guessing the tips are just plain copper.
kWeld is designed to weld nickel or steel based tabs of up to 0.3mm. I have tried copper in the past, which doesn't work. Aluminium is between those in terms of thermal and electrical conductivity. I haven't tested that, it might or might not work.
Oh, I see...I thought your tests around 5:15 are on aluminum, or are they not? Aluminum can be spot welded, but it takes good control of the energy introduced; as it appears your machine can administer, and it helps to have one of the more non-conductive alloys. Yes copper is very difficult, especially with copper electrodes. The precise power needed is important so the aluminum does not vaporize, but a lot of power is needed to heat it well. I'm surprised you haven't tried this...aluminum spot welding is very lucrative.
...welding aluminum would not damage the welder, will it? Would it help to have a input source with a higher IR, like 300A max lipo's (this was my plan...with less efficient lipos it should be less likely to cause damage to the welder, no?)
PDTech BigBot no, these are Nickel tabs. But you're right, and there are a lot of other ideas to try out. Like welding car body stud welding, jewellry welding, welding fuse wires to batteries, using different electrode materials, electrode water cooling, etc. I just don't have enough time for that, as kWeld is only a part of my ongoing business and customer design projects are currently using up most of my time.
allright, I'll give it a shot when I get the welder. I see tungsten being used with success with aluminum so I bought a few of those electrodes. I think it "should" work...I see other aluminum spot welders described as single pulse captive types, which sounds about like what you have here.
How do I purchase in USA?
please check out the contact info at the product page on www.keenlab.de
What thermometer is that?
DT 8220
That lipo needs to be in a fire bag hah
yup :-)