Sunkko Spot Welder

I recently purchased this spot welder but today when I tried to use it, 99% of my welds only affected the 0.15mm pure ni strip; my 18650 barely had any welds on it. The one or two good welds I got were easily ripped off…I feel that the fact that it is the 110V version is where the problem lies, but I don’t know enough about Sunkko to determine if that is the issues. I understand that there is a 220V version, but I think my location in the US would be unable to handle that…would anyone happen to know what the cause of these weak welds might be?

I had a similar issue with my homemade spot welder initially. It’s a combination of putting to much pressure on the electrodes/not enough power.

I had to shorten my welding leads and apply less pressure and I haven’t had an issue since. Pictures always help as well.

This is the type of welds I am currently getting. TBH, I have no control over the power issue; I live in an apartment in the US. I do not have any lengthy welding leads that I can adjust as well. Overall, I’ll probably end up having to return the Sunkko I bought.

To me from there it doesn’t look like ya have a power issue and ya might just be applying to much pressure on the electrodes.

But that doesn’t really make sense if you aren’t using the extended leads. Can you adjust the weld pressure at all?

I was about to buy a sunko originally and they just aren’t worth it in my mind compared to building your own MOT based spot welder as that’s exactly what they are.

Yes, there is a pressure adjustment knob on the top of the sunkko. However, using it at any setting does not seem to yield any different results.

I personally tried that version and didn’t like it which is why I switched to the 709a model which after some tuning left me some very good welds and I can even do some great double layer welds with .015

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Jeez I knew it was underpowered but i didn’t think it would have any issues welding 0.15mm. @Kit if you have an old microwave (at least 900w preferably more) something like this

is what I’m using and it definitely does the trick, another seller recently started selling his own version and he has a decent broken English description of how to build your own and what affects what,searchweb201602_5_10152_10151_10065_10344_10130_10068_10547_10342_10343_10340_10548_10341_10696_10084_10083_10618_10139_10307_10059_308_100031_10103_10624_10623_10622_10621_10620,searchweb201603_11,ppcSwitch_2&algo_expid=468d048e-f3ee-43fe-be46-a9159c2a96bd-0&algo_pvid=468d048e-f3ee-43fe-be46-a9159c2a96bd&priceBeautifyAB=0

And it honestly seems these DIY boards from China have more adjustability then what the sunkko has, they just typically have a 1500w transformer, which is a bit harder to find.

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I have considered the DiY path…but I also have the Spot Welder that is pretty popular on the forums. My issue with that device is the power available though; I’d have to buy another lipo for $80 to run in parallel.