Rapid Soda Cooler

Hello everyone, my name is Aitrieus Wright and I'm a second year Mechanical Engineering student at San Jose State University. As a native Californian, summer heats reaching as high as 100° F is not something unfamiliar to me. Finding ways to cool off becomes a seasonal a effort and is the inspiration for my project, the Rapid Soda Cooler. The soda cooler is meant to serve as a quicker, more convenient method to cooling a canned beverage when compared to traditional coolers or freezers, which can be large and difficult to travel with. It does this by rotating a can, coating it in a bath of cold water from below and constant stream from above. For this project the main method of fabrication used was additive manufacturing, paired with Fusion 360's CAD utilities.

• 3D printer
• 3D printer filament
• DC motor (2x)
• Motor speed controller
• Water pump tubing
• Solar battery
• Pair of electrical wires (2x)
• Pair of electrical wires into USB type-A head
• Adhesive/water sealant

To design the tub I simply had to make a container capable of holding enough water to partially submerge a soda can laid down lengthwise. The complexity in the design though comes when factoring in the other functional parts of the cooler. A rod meant to spin the can, a water pump, and the water pumps exit tube were the additional parts that the tub had to be designed around. To assist me in visualizing the final product and its functionality I used a caliper to measure the dimensions of a real can and add this can, along with the rod, into the CAD.

The final design sees the tub's dimensions at 155x120x135mm. These dimensions were chosen after considering my 3D printer's size and the amount of filament available. The final design also includes a hole for the water pump (the biggest hole), a hole for the shaft of a motor to connect into the rod (above water pump hole), a hole for the water pump's exit tube (up in the corner), and a recess in the wall of the tub for the rod to rest.

I began designing the water pump system before the rod, seeing as it was a more complex part and would require more time. I did some research, studied how proper water pumps function, and then came up with the simple design as shown above. The pump has some depth for it to take in a good amount of water and the fan's diameter sits just short of the walls inside the pump to allow it to spin with less friction. The pump's shell also has a recess coupled with a hole slightly bigger than the motor shaft's diameter so that the chin of the motor could rest in the pump, spin without any friction against the pump, and to reduce the amount of water-sealant required.

The rod was the final part designed and was done so based on a couple of conditions. First, it's length had to extend across the inside of the tub and into the recess of the opposing wall so it could be supported at two points. Then the second condition was that it had to be thick enough to keep a soda can from falling past it, but also thin enough that part of the can could soak in the water beneath. To determine a proper size for the rod the mock soda can was again used in the CAD for visual aid. Both the rod and the fan have press-fit holes that are meant to be big enough to let the motors' shafts in but also small enough that it tightly engages the motor.

After the main chunk of CAD was finished practical print tests had to be done to verify that all holes were the proper fit. Fit testing is done to ensure that the final big print has as little error as possible and to avoid multiple prints which would cost a lot of filament. The actual testing was a matter of printing small parts containing the dimensioned holes, matching the holes with their parts in the design, and then repeating until sufficient hole sizes were found for every fit.

After verifying that all fittings are correct it was time to finally print. To do this I exported all the finalized CAD files into ".stl" files to then be uploaded to Cura for slicing and then printed. The first part printed was the big tub portion since it was about a 31 hour print. The smaller parts were a lot faster with the longest out of the bunch being the rod print which was about a 2 hour print. All prints were fabricated on Creality Ender 3's, from both my own and the one's my club owns on campus.

Once all the parts were printing the final step was to assemble everything together and then test it. The first pieces I put together was the water pump and its motor. To attach this and all the other parts I used a transparent adhesive that also doubled as the water sealant. I made sure to thoroughly cover any gaps with the adhesive to ensure that no water would leak out. Once those pieces were attached I moved on to adding the rod and another motor. I fastened the rod into its recess in the wall and then inserted the motor through the tub's wall and into the rod. After that I added some adhesive again to mount the motor and seal off any gaps. The final part of the assembly was the electronics. I used a preassembled motor controller so all this step consisted of was mainly wiring and connecting all the electronics together. The motor controller also had neat markings to distinguish where power should be routed through, as well as where the positive and negative connections of a device should be made. Once everything was finally assembled I powered on the battery and it ran as shown above, thus completing this project.

My Fusion 360 files: