Hack a Toaster Oven for Reflow Soldering

Step 8: Final Circuit Assembly

Look at the diagrams while doing the next few steps.

Now you can screw the relay into the bottom side of the PCB, the relay should have come with the screws you need already. Check the orientation of the relay, but the hole spacing is slightly different on each side so it's not really possible to screw it in backwards.

Solder the fan's wires to the PCB, watch your polarity. (I didn't have any connectors, but if you want, use a polarized Molex or JST connector for this)

Solder the modified USB charger's wires to the PCB, watch your polarity. (I didn't have any connectors, but if you want, use a polarized Molex or JST connector for this)

Use a flux cleaner to clean the flux off the PCB. I have this spray can that is absolutely magical at this job. I've discovered that the flux actually affects the thermocouple readings greatly so cleaning it is important.

Tuck away anything that is loose, and secure it. I tucked everything under the PCB and secured it down with electrical tape.