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Boss level custom spot welder


Are the plans/PCBs released somewhere for people to build this shared invention ?


Just follow the yellow brick road…:laughing:


No worries. Glad it could help someone… :thumbsup:


Sure no problem! I will ask him to write a step by step guide. Do you want him to pay for the patent too?
Get real dude. Of course he shared parts at the korean forums with other engineers but he will not give away the whole thing.


Makes no sense - he either wants to benefit from the money and keep it closed or he is not interested in the money and would therefor make it as public as he possibly can.

Disclaimer: I totally understand if he wants to benefit from his work and not make it public. Sad for us but understandable.


Check his youtube videos. Read the comments. People was begging him to sell the welder. He refused for years to do so. A few months ago he opened his hands because sharing his invention makes him happy. He uses top class korean components and spends lots of hours doing them. The very few bucks he makes per unit is not even close to minimal wage in Korea. This is his passion, his hobby. If that makes no Sense to you just buy another welder or make a custom unit out of a microwave.

Just go ahead and buy another welder if you will. He doesn’t even plan to make a sales thread.
Never ever again question his noble intentions.


I also have no problem with him selling his stuff.
For example, Malectrics (the first link) both sells his design as kit or finished product. But he also release all the schematics/PCBs on github :

Some other only sell their desigh (like the JP spot welder on endless sphere). That is absolutely fine.

So please calm down. Your definition of “not selling” and “sharing” is quite a personnal one, that’s all.
I have nothing against him, quite the contrary, I find his stuff great !


Sounds like he is saving the world - one spot welder at a time.

BTW: I already have a DIY spot welder - made from KaeptnBalu’s schematics.


My definition is actually not mine. It comes from a personal chat with him. He refused to make a group buy or accept big orders. That’s not my personal opinion, it is the truth. He is happy just sending a unit every now and then. Btw I am not entitled to speak in his name. I talk about the things I know for sure. That’s all.


I only said it because i would love to share my passion for electronics with others. I make battery packs. I make vapor mods. I even do woodwork but i only said it to get his work out there not to make a business off it but to help him spread his idea. Take for instance the people who made great things we use now if they didn’t spread their idea then it wouldnt have gotten nowhere or someone else would have done it for benefit. Better him then someone else who will take it. Just an opinion


Oh, that’s a Great…

I do not speak English well.
So, I’m hard at work on
I can hardly understand the text of this forum.
I barely understand using Google Translate.
Especially colloquialism thinks for a long time.


I got information about other spot welders.
I think the principle of operation is similar. ^^;


Hi aulakiria,
Great design that you built !
I wish I had as much knowledge in electronic as you do !


Hi @aulakiria,

thanks for your nice design. I’m definitely in! Wanted to build another welder but This one is so much slicker! :slight_smile:


Can someone explain to me what the actual difference is to the KaeptnBalu spot welder we have all been using?
As far as I can see this spot welder is also “just” another MosFET switch that shorts the batteries for a couple of milliseconds. Without a large capacitor bank I don’t understand how the short could happen “beyond the LiPo”.
Did anyone actually measure what the lipo experiences?


Thank you. Akira
I was 45 years old and studied electricity.
There is no royal road to study. ^^;


As a result of the measurement by a professional engineer in Korea, it was measured at 880A.


So it is like the other spot welders :confused:
I was under the impression that the USP of this thing is the ability to use Lipos but if it is “just” a Mosfet switch then this should not be done. Car batteries only!

@rojitor why would you say that Lipos are safe to use when there is no evidence?


Can you back this up - I am concerned that there might be some misinformation. I can’t find anything on the use of Lipos and how he made it safe.

@guys like @Lambjr088: please wait for the replies befor using this with Lipos. It could be that @rojitor just got lucky and that this spot welder indeed shorts the Lipo leading to increased risk of it failing.


I might be lucky too. I have built a 10s4p pack and it didnt cause the lipo any harm or even for it to warm up