I was looking around at the different laser chiller options and some of the DIY setups. While some were neat and impressive, they seemed too big and too costly for the most part. I wanted something small, that could keep my laser cool and not take up too much space under the bench. I finally settled on a counter top ice makerwith some rv antifreeze. Igloo Compact Ice Maker - Assorted Colors - Sam's Club It cost 99$ + tax at Sams and with zero modifications, I dropped the original pump from my DK40 laser into the reservoir. I filled it with 2/3 gallon of rv anti freezeand dropped the return line into the ice tray so that the coolant overflows directly into it. Right now I simply turn the unit on and off to control the temperature, but I will be building a controller to handle the power cycling.
Been busy working on my Arduino sketch and finally a Windows application to control the Arduino controller. I currently am using a ArduinoNano, a Sainsmart 2channel relay, a 100k thermistor and a 10k resistor. It's currently in testing now, to be wired into the unit once I have some safeguards built into the control firmware. Currently there is two way communication between the firmware and Windows application. You can start and stop the controller from the software and retrieve data. I will be adding in support for sending
updates to the firmware to change the device on the fly. Current cost of the control module is just about 5$.
The unit has been working really well, I was running an hour and a half etch last night and watching a movie, I forgot to check the temp and when I did it was at 9 degrees. I left it off for the rest of the etch, roughly a half hour and it finished the etch at about 18 degrees. I expect the unit to cycle on and off once it reaches temperature about every 15 minutes, more as I ramp up the power on the unit.