Soemarko Ridwan

iOS & Web Developer ⟡ Coffee Addict ⟡ Scuba Diver

Project Katara - Build Log 5: Back to Drawing Board

… mostly. I’ve failed to achieve the $20 Anova since the heating element price jumped almost 10x. I planned on using the one that costs $1.50, but it was zappy and splodey, so scratched that. This project felt cursed, it’s one problem after another. But I’ve spent a lot of time designing in Fusion 360, and writing codes. Weeks worth of work, and those are sunk cost. I want to see this through.

As posted in Build Log 3, I have soldered all the components and all the connectors, after my 1mm nozzle arrived, I decided to redesigned and reprint the enclosure so the new parts have their proper mounts. I have to reprint the bottom part because of the new water heater anyway. And oh boy 1mm nozzle is fast, 0.5mm layer height. Cut my 12 hours print down to 6 hours.

After that’s done. Putting it back together, that god-dammed Fotek SSR decides to bite me in the ass… again. That shit leak current. During testing I noticed the water temperature kept on rising despite it has reached the target temp. So I stop the PID. Still rising. Kill everything. Put the main wire through an amp-meter, it pulled 3 amp when idle. It’s only supposed to power the ESP32. ESP32 doesn’t need 3 amp on 220V. But when I turn on the PID I saw the current draw jumped to 6ish amp. So confirmed FOTEK is the problem. Some leaks are common with SSR, but 50%?!

Good SSR

The very next day I decided to test it with one of my good SSR. It’s a dual SSR, so quite an overkill, but it’s the only non-Fotek SSR I have. Night and day. 15mA on idle, 40mA when I turn the pump on, and 6-ish amp when everything is on. Which is about right, 1500 Watt / 240V = 6.25 A. MK3 is finally done.

Next post: Build Log 6: Build Guide.