Hey Lox I have to ask you what you mean with aluminum sheet and what you have done with it? I have started mine yesterday and actually the soldering is fun. My joints look good to me and I’ll post some pics when I’m done.
see that aluminium the mosfets sit on: https://cdn.instructables.com/FQ5/S6OA/IRLQQN5S/FQ5S6OAIRLQQN5S.LARGE.jpg he talks about it in the video
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On the MOSFET side of the board you should put aluminium on top of the silver rectangle so the mosfets are level. If you watch the video he shows how to do it. If you need the template for the aluminium, pm me.
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Is that your board Maxid? Or is that his?
It must be his.
Mine is far away from complete 
I meant Maxid or the creator of the welder. Sorry for the misunderstanding.
that is an image from the instructable website. mine is wrapped in heatshrink - otherwise I would have posted an image of it
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I have done some work and thanks to @lox897 I understood the aluminum part. Please note that I have no idea what I’m doing and if this thing works everybody is able to do that. I have three more questions. First: What to do with the fets? I don’t know if I have to cut some legs or not. Second: Do I have to scratch the traces from the pcb like the German dude in the video? Third: Do I connect the main pcb (12V and, GND) direct to a battery with thin wire for continues supply? Or do I need an extra 12 Volt supply because of the current? Thanks
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1st: You don’t need to cut the legs. 2nd: No, he fixed that quickly although I see silver on my board connecting to the mosfet board so I am not sure. Hopefully someone can confirm. 3rd: You can connect the 12v to the big 12v battery or use a 3s lipo or wall power supply.
Thanks! 1:
I don’t know how these fets work, so I have ask again to make sure. Do you have a detailed picture? 2: I heard that too but in the video it looks live he scratched away a bridge witch is on my pcb as well. @Maxid what have you done? 3: Thanks again!
The pcb we got is a newer version so no need to scratch anything. Just solder everything as it is now and you should be fine. Also when testing don’t be surprised that you need to hold the foot switch down for a second until the spark is actually delivered - i tried to only have contact as short as possible and thought it is not working
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Could you post a pic of the traces you are talking about?
EDIT: Did you also make sure you put the components on with the right polarity? The resistor at the top left looks like it has the writing facing inwards, I think it is supposed to be outwards
@lox897
Of course.
But I think maxid left them and his is working. So should be good!
I checked the components for polarity, but I was unsure with the top left one. I don’t know what it is and the legs had the same length so I thought that there is no polarity. Do resistors have a polarity? I know capacitors, diodes und LEDs have a polarity.
EDIT: I checked and resistors don’t have a polarity. Is the top left part a resistor in a different shape?
Yeah those traces are fine. I think it is only the brown resistors that have polarity. Maybe switch it just in case.
There you can see that it is meant to be that way. The fets have three legs: one for the current to enter and one to leave and one gate to “switch” the fet’s state (basically opening and closing the circuit to allow the current to flow). If you would scratch the marked positions you would cut the circuit and the current would have no way to flow to - so please don’t do it. The guy was talking about something else in the video - we do not have this issue anymore. Also there are different types of capacitors: http://2.bp.blogspot.com/-e4Y8eklya-M/T5tsyCnhwxI/AAAAAAAAAHI/CzLyc6APv88/s1600/capacitor1.png the one you are talking about has no polarity so it does not matter what way you mount it. Hope this helps - if you have further questions let me know.
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PCBs are fine, no need to cut/remove anything on them. (other than cut the single PCB into two pieces 
)
FYI: The old PCB - what is presented on youtube - had an issue: not only the leg on the side but also the middle leg was connected and had to be cut manually otherwise it shorted the gate. This issue was fixed in the PCB design long time ago and now nothing to be cut…
R, J.
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looks beautiful - mine was such a mess that I had to wrap it in heatshrink just so that I do not have to look at it 
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I know exactly what you mean.
Some of my projects turned out worse then expected, but for some reason I’m very passionated with this one.
I only have clear shrink so it has to look cool at least.
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