When working with surface-mount components, things can get a bit tricky with soldering. A reflow oven heats on a specific cycle to melt the solder or solder paste. While a rework-station may be great as well, a simple reflow oven can be helpful in making or repairing PCBs.
This project aims to create a solder reflow oven that is capable of reflowing PCBs. There are some other interesting features added as well. The original version of this oven used an ATMega8 while the updated version has an Arduino Nano with an ATMega328. The interface is updated as well. Below is the original circuit board made. It has since been scrapped.
After gutting the oven, I added a power toggle and a push button. I used an automotive relay to switch the heating elements on and off. The AVR switches a small transistor on which pulls the relay, turning the heaters on. There is a I2C thermocouple inside the oven to measure the temperature. There is also a power board that is used to supply 5V+ and 12V+ to the relay and the AVR. Below is also a shot of the prelimenary mockup of the design.
I remade the front panel by cutting a piece of sheet metal and just remaking the panel and adding some pushbuttons and an LCD screen. The pushbuttons came out of an old EEPROM programmer.
Above is a drawing of the front panel and the holes are drawn to scale.
The code is C for AVR. Either AVR-Dude or Arduino can be used to compile and upload the code.