If you hold down the pedal, it’s the one that ends with ms.
So god damn stoked to get mines up and running. Finally got the battery from Hobbyking. Building stuff bitches!!! Well fixing stuff first …thanks Unik POS battery.
Thanks for all the info gents
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T = 50.62 for 0.15 to .15 50j and 1150a
from my experience of 5ah green and red lipos the difference is around 400A, green was at around 1800 while the red lipos were around 1400A, both batteries got the same welds more or less
I was saying that above 1300A or so the results will be always good, up to I would say around 70J welds
Not that a 1000A and 1800A power source work the same
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Why don’t you just solder the two male XT90’s right to the input of the welder? You could eliminate the XT150 and additional wiring entirely, and still have a system with detachable batteries. What is that black thing left to the upper XT150 in the pictures? Just a sleeve, right?
Yes, based on my tests here. I had been using solid strips of pure 0.3mm nickel, and it doesn’t weld that reliably here. It depends on what you actually use - Hilumin (nickel plated steel) welds significantly easier, and slotted strips help guiding the current and also improve the situation.
It’s really just Ohm’s law. Desired current is 1500A. The resistance of the kWeld system is roughly 3.2 milliOhms (stock cables). The weld spot itself contributes another 1 milliOhm typical. This gives 4.2 milliOhms total. To push 1500A through that, you need U = R*I = 6.3V from an ideal battery. For every milliOhm of battery’s internal resistance, you need another 1.5V accordingly. Or in other words, for every volt above 6.3V that the battery has, it needs to have 1 milliOhm of internal resistance to stay in the sweet spot for the current. A 3S battery therefore needs to have 12-6.3 = 5.7 mOhms. Then calculate the power loss in the battery: P = 0.5 * R * I^2 = 6412 W. That explains why they heat up quickly, even though the pulses are short. Now consider a 6S battery. That must have an internal resistance of 24-6.3 = 17.7 mOhms. Then P = 19912W. You see that the power loss in that battery is huge. This is why I recommend 2S to 3S batteries for the welder.
Having the sides touch instead of the tips gives you an incorrect calibration result. It is very importan to have the tips touch correctly (pushing the conical areas is okay). Make sure you get no sparks, otherwise repeat. This is important for the energy metering to work properly.
That should definitely be possible without problems, especially because you are running the welder at higher amperage than I do here, and it works well here. The result also depends on the type and thickness of the battery can itself, is it possible that your batteries have aluminium cans? kWeld can definitely not weld nickel strips to that material.
Another important advice (sorry the user manual lacks this info): kWeld does not like voltage applied to its electrodes; this can happen when accidentally touching different poles of your (large) battery under construction. Please be careful to avoid that, otherwise you may kill the unit.
That’s public on the website:
keenlab UG
Langestrasse 9
26388 Wilhelmshaven
Germany
Much appreciated from my side!
If you have, please make tests with slotted strips. You should get better results with that. Nevertheless, I share your opinion that welding overly thick strips to your battery requires a lot of heat that can potentially damage the cell internals. What happens to the back of your blade also happens to the battery. When a customer asks me, then my recommendtion always is to rethink the solution and check if thinner material might be the better option.
Exactly. These are officially called “resistance spot welders”, as the operating principle is to push current through the electrical resistance of the material to weld.
It’s voltage that causes current, and it’s current that causes heat. So the right term would be ‘current’ punch. I hope that I could clear up that relationship in my above calculations 
That’s a clear sign of bad calibration, please repeat that and check. 8J barely be enough to weld 0.1mm nickel.
The joule metering algorithm automatically adapts to varying situations (battery voltage, current, corrosion,…) A higher current allows to weld thicker material, and it keeps the pulse duration shorter. The latter is desirable as it avoids heat spreading out during the pulse. That causes some variation, and is generally good to experiment to find the correct setting before making large batteries. Do this for each type of connection: strip to negative, strip to positive, strip to strip. Different types of batteries again can require varying this, because they may have cans of different thickness for example.
It’s important to get as little arcing as possible, hence push hard and work with clean surfaces where possible.
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Dident want to have a floating live plug when using the kcaps (when cutting Nickle bits go every we’re and I’m scared some day it will short a battery) did suggest it earlya in this thread for any one thinking of doing more than 0.2mm
also with the warmest part of the unit after use was the XT90 (I presume this is because this is the part of the system has the hiest resistance) so I thought using a XT150 with the kcaps in the futere was a good idea ones you sorted it out.
the XT150 neg conection?
its a dule XT90 to XT150. 2 AWG 10 cables striped is a super tight stuff in to a XT150 and there is no way the insulation is going in the XT150 case so you have to strip extra so multiple layers of shrink tubing around the double AWG10 silicon cables next to the XT150
I’m consistently getting 2.15 with the XT150 use to get 2.35 with the XT90 before all with stock cables. is this some thing to be concerned with how low is some thing off and why im welding with such low Jules setting? I think my battery cells resistance from memory is 1.1-1.4 milliohm each resistance and I have 3 in series 2 sets of them in parallel. so 1.2*3=3.6 derided by the 2 packs 1.8 mill ohm thats leaves 0.35 mill ohms of resistance for the Kweld system and probes seems to low even for a bad calibration unless I’m doing maths wrong some were.
I take it then the dule 3s 6ah Turnigy green Graphene delivering 1600-1800amps im using is pretty much the best power source I could be using no point in changing as a few other options was discussed earlya
the 0.15 nickel welds grate to it so definitely not Ali can and im struggling with craft blades below 100j starting to think I need to try 0.3mm suppler that’s not nikon
found it after posting sent it beginning of last week hopefully its arrived
Got it I was afraid that this would be some kind of fuse or whatever.
The number should be independent from the amount of current that flows. Thinking of this, it could also be a flaw in the algorithm. The welder waits for the current to ramp up before starting to make measurements. The time that this needs depends on the amount of inductance in the system, and the waiting time may be too short. This would explain why the measured resistance varies in your case. Do you have the firmware updater so that we can experiment with this?
I’m afraid yes The displayed resistance is that of the output of the kWeld unit only (output cables, electrode holders, electrode tips). It is very important to press the conical ares of the tips together, as the wanted result is all resistance that the system later has when welding. Also make sure that the set screws are tight (don’t overtorque, as it is copper), maybe also check all the screws. In rare cases a customer even had to disassemble the bus bars to clean the surfaces. They need to make good contact over the entire surface, or the accuracy of the current measurement is reduced.
There must be something wrong with your unit or setup, otherwise you wouldn’t need to dial in such low Joule values to get the wanted result.
Arrived this week, I’ll inspect it early next week.
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Yes some were but I only have my MacBook with me for the next few weeks windows PC at home if I need to run software.
So not like a Zs then calculating the supply in as well. As I thought it did.
In my head the lower the resistance of the calibration the better a bad assembly would add resistance not take it away.
I did check all the connections and tweak all the bolts when I opened it up when adding the XT150 connectors would explain the .2 drop (may or may not have soldered the red and black connectors the wrong way round and it’s easya to unbolt than re solder didn’t want to forget one day and power it up with the - and + reversed)
I think this is the correct one
I did 10 calibrations pushing the tips together and I’m getting 2.16 mR pretty consistently unless I don’t push them together so hard then iv getting 2.20ish
Doesn’t seem to matter what battery I use if it’s a 6Ah or 12Ah only affects the amps delivered as expected.
3 different Nickle pieces non of them rusted after 5 days in salt water 1 and 2 are 0.15 3rd pice is 0.2
Perfect! That’s what I had expected. In that case, no need for experiments. And yes, that’s the firmware updater.
So iv not Heard any thing back from this since you revived the return back over a month ago unless iv missed some thing. Any update?
Could you explain that import regulation ? Is it the item or sender country based ?
It’s one part in the kweld which is restricted to import into Russia and maybe other countries, but I can’t tell you about that.
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@tatus1969 Dear Frank, could you tell which component (or a general component family) creates that problem ? Is it only applied in Russia or any other countries too, Turkey for example ?
Resistance spot welders fall under the “dual use” class of instruments and are regarded as potential tools for building nuclear weapons. Even though nobody will be able to weld together titanium sheet metal for a centrifuge for uranium enrichment with a kWeld, the governmental regulations are made this way. Even when I export to other countries like US, I have to basically swear by god that I don’t sell the tool for such a purpose. And Russia is, among a few other countries like the Iran, explicitly put under embargo for these “dual use” goods. That’s why I decided to exclude these countries, even though I made rightfully be able to sell to them but I don’t want to risk trouble from some stupid EU official who knows nothing about electronics but everything about his right for law enforcement.
It should be the same story for Malectrics, and I’m not sure if he is aware of this potential risk.
edit: the same story holds for the Maxwell ultracapacitors, my guess is that you could use them to build railguns. That’s actually which made me aware of this problem, as I get them from Digikey and they put corresponding warnings on their invoice in that case.
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I’m sorry but I might have lost track of this as we have just moved to a different place with my entire family and business. I recall having received a kSupply module with a broken trim pot and had put that to my shelf of stuff for later salvaging or dumping. Haven’t I sent you a replacement module? And I can’t find how to relate your forum id here to your real name/address/email. No finds for “darkie02” in my email archive. Sorry for that. Please contact me via email (frank.boeh@keenlab.de) with reference to this thread, and I’ll sort that out for your asap.
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I see your point and that situation is really sad. I checked the aliexpress and sunkko models are continuously being shipped to Russia and US. So the problem is caused by the EU officials in your country ? No allowable power interval or etc. is given then, just “spot welders export” is forbidden ?
I’m not sure that adhering strictly to export regulations is cause for concern. It is someone abiding by the regulations which apply. We all know Chinese companies don’t really care about that kind of thing at all.
Are you on an export embargo in turkey and affected?
There are about 160 US nukes in Turkey, not everything makes sense in this world either way.
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I didnt quite check the export embargoes throughly but sure I must do that. We have to obey the rules and not draw negative attraction upon esk8ing.
160 ? The number which is spoken is quite lower than that (50) and its not certain if there is any… If there really are, none of them belongs to TR and all must be in US military bases in TR.