$1 Liquid Cooler

thingiverse

I decided to build this prototype after reading some papers on cooling the human body through pulse points. The human body has several pulse points, and one of the major ones is in the wrist where blood flows very close to the skin. When these areas are cooled, the entire body is effectively cooled as the cooled blood is pumped around, bringing down your body temperature. If this ends up working, I wanted to create a portable rig to wear while riding my motorcycle in 100F+ weather. This prototype uses a United States dollar coin and it fits quite snugly with a small bead of hot glue to seal it. My print actually leaked through a few of the layers very slowly, a drop every 30 seconds or so, but that's only because I had recently changed filaments and the new filament needs to be printed at a higher temperature - that issue is now fixed. It requires more work, as the hose barbs should be made to glue in instead of one piece, allowing them to print vertically so they stay round. As for testing, I pumped tap water through it with a small pump at a quite slow rate, and the output tube was barely a stream - but I applied a 40W soldering iron to the coin for several minutes, and you could put your finger on the coin right next to the soldering iron and it stayed cool to the touch. I recently added a spiral based cooler in an attempt to increase flow. It has been printed and printed perfectly, but hasn't been tested yet. I used the following print settings: RepRap printer brand, Ebay Prusa i3 kit as my printer model, no rafts, yes supports, 0.2 or lower resolution, 30% infill, and I printed it on its back, not on the tips of the hose barbs as it is in thingiverse view - I also used two shells, prints with support now for the hose barbs, but V2 will have glue in hose barbs that print vertically so they don't deform.