DIY Reflow Oven Designed Using an Arduino Pro Mini and Touchscreen Interface

Engineers and makers have been converting toaster ovens into PCB reflow machines as a way to save money over buying expensive counterparts. It’s an ingenious idea, but it can be dangerous if you don’t know what you’re doing, especially with mains voltage. That said, Mangey_Dog has designed a reflow oven that looks more like he bought it off the shelf over a toaster oven with a juiced-up heating element.

Like most engineers, Mangey_Dog’s budget restricted him from buying all new components, so he opted to go with a used German-made 1000-watt Kleiner pizza oven, which had the dimensions he needed for his build. He soon found that the oven’s heating elements were slow at heating up to temperature (rising at one degree per second), so he added ceramic thermal insulation and outfitted the oven with a halogen heating element, which boosted the oven up to 6-degrees per second.

To round out his build, Mangey_Dog implemented an Arduino Pro Mini and touchscreen interface to control the oven, a thermocouple to maintain accurate temperature readings, and a dimmer module (rated @ 4000W) to adjust the heating elements, rather than using a solid-state relay. The Arduino is used in conjunction with the dimmer to provide fine control over heating temperatures within the chamber, which allowed him to program settings for lead/lead-free solder, and several different profiles as well.

As mentioned earlier, messing around with mains electricity can be risky, as Mangey_Dog found out while building his project, stating, “As I mention in my video, I made a little mistake that triggered the RCD for the circuit I was on in the house. It was stupid as I was taking logic level digital knowledge and tried to use that on a mains connected circuit. It was an educated guess, and I was WRONG! I really should have seeked (sic) advice first before trying to filter a live mains connected electronics.”