Got the Spot Welder built today, works most of the time. Main issue is my timing relay board only does 0.1s increments so occasionally burns right through 2 levels of 0.2 nickel. Got another timer board on the way that goes to 0.01s increments. Will allow for a more of a precise timing pulse.
I am also based in London (Islington) and have everything for my build except a spot welder. Would anyone be able to help out?
I want to do the same. But it’s hard to figure out the timer controller in the picture.
I have already got my electrodes setup but just need to do the electriconics side of it
I’ve swapped to another timer board as the previous one only went as low as 0.1s. The new board does 0.01s, and I’ve found th sweet spot with my welder around 0.06-0.07s
Here’s the new timer board I’m using, I’ve got it set to 0.5s delay then 0.07s pulse on relay
Thanks,
I got 2 coils of 6AWG wire, it seems like enough.
I also have a lot of 10AWG solid core wire which might be better since I can have more coils.
Ive already got a momentary switch like you
Nice, should be okay I used 16mm2 cable. You can check out the output voltage using multimeter, just set it to AC, I was getting about 3.5V.
Ok.
I need to research on connecting the transformer to mains, Do you happen to have more pictures of your wiring?
And anything thing else you bought? Just want to make one order of the stuff I need
I don’t I’m afraid, but it’s quite simple. Earth goes to the transformer itself, I used one of the screw holes in the base. Brown or blue (doesn’t matter) goes to primary coil, other colour goes to NO (normally open) on the timer board. Then the common on the goes back to the timer board. The two going to the relay can be swapped, doesn’t matter which goes to common and NO.
OK I was going to earth it using this method too.
I guess theres enough resources online to help me, thanks
I will get that timer board, it looks better than the one you had before
Wider input voltage for operation too. I used a spare 12DC supply, connected using 5.5/2.1mm connector.
So instead of micro USB 5.0V power supply you used DC12V?
Yeah, an old 12DC power supply from an old WiFi hub I think it was.
Any input? Seems like theres much less parts required in comparision to the ones I have seen online
The question mark should remain empty? Relay basically has two positions open and closed. Top is normally closed, ie the circuit is complete. Normally open (bottom) means the circuit is NOT complete and therefore the transformer is off when the relay is off
Thanks, I wasnt quite sure what Signal GND meant thats why 
Also do you think that diagram I showed in the previous post is complete?
What is the bottom right bit? It three pin like in a PC tower power supply? Wiring looks good, just not sure about some of the loops on the bottom right connector.
Yes it is (like a kettle cable connector)
I think it comes pre wired and just have to wire the other 3 wires which I have done.
Good work both of you! I decided that welding batteries was probably too dangerous for me to keep looking for DIY alternatives which might also end up costing me even more…and took delivery of a Sunkko 787G last week.
First tests have been awesome. Excited to get my build on the go, this road block has lasted for about 2 months…!