• Integration

    Revoxdyna • 08/26/2022 at 14:57 • 0 comments

    The following is the first version of the prototype.

    whole assembly with my feet


    Module Integration with the shoe

    The cooler module with insole

    Next time:

    1. The whole setup was quite bulky, I would try to minimize the size or redistribute everything and make them look nicer.
    2. The shoe mount is not entirely firm
    3. The workmanship of the tube bending and the water inlet outlet has to be improved.
    4. The insole and cooling tank can not be detached easily, which may hinder the maintenance job or fill up the water tank.
    5. No idea about the water level


  • Further Experiment

    Revoxdyna • 08/26/2022 at 14:41 • 0 comments

    A few more tests were conducted to get the performance.

    Objective:

    1. To measure the max. temperature difference.
    2. To get the time for the steady stage

    Experiment setup:

    Data of the cooling:

    Data of the water tank: 

    Results:

    1. The max. temperature difference of the insole was 4.9 deg
    2. It took around 25 mins to get the steady stage
    3. The max. temperature difference of the water tank was 5.5 deg

    Conclusion:

    Although the temp. different was 4.9 deg, the water droplets were condensed on the insole and cooling pipe already. After the testing, I put my feet on the cooled insole and the cool feeling ran through my feet. 

  • Shoes Mount Design

    Revoxdyna • 08/26/2022 at 11:33 • 0 comments

    The requirement for the shoe mount is simple:

    able to mount on a shoe tightly

    I had a quick thought and designed a mount and test.

    The following is the result.

    It fit the shoe perfectly, however, it could not fit into another shoe. Therefore, the shoe mount must be modularized (design a mount for a special type of shoe) or add a degree of freedom to adopt more shoes.

    The following is the design up to this moment. The moving parts would be self-assembled during 3D printing. This is the first time I tried to use this technique and the result was acceptable.

  • Water Tank Design

    Revoxdyna • 08/26/2022 at 10:56 • 0 comments

    The requirement of the water tank:

    1. the size should be as small as possible 
    2. able to fill up the insole
    3. the cooling module should be removable for a more powerful cooler or other purposes
    4. good contact with the cooler surface
    5. no leakage

    The design of the water tank is below after testing

    Experiment setup

    The water tank shape could be further adjusted and also the way to couple with the cooler to get better performance. Since I could achieve the aforementioned requirement, I decided to move forward to see what happened.

  • Insole Design

    Revoxdyna • 08/25/2022 at 14:14 • 0 comments

    The insole design was simple.

    The cooling pipes run through as much as the area of the feet. 

    Attach a copper plate to the pipe

    However, the cooling area may not be able to extend to the whole feet, and also the flat copper could be designed better to further increase the surface area. Therefore, the copper wires were used instead of the copper plate. As the copper wires were soft, the feet would have better contact with the insole.

    The insole was welded and grided.  After testing, the wires were able to deform a little bit to adopt the shape of my feet. I am happy with the design, of course, it can be better and that will be improved next time.

  • Experimental Setup

    Revoxdyna • 08/25/2022 at 14:05 • 0 comments

    There are a few items I need to test before I start the design.

    Testing items and results:

    1. Verify the cooling effect:
      The cooling time is obviously decreased with the pump switched on. It will take  ~15 mins to have the cool feeling without the pump and ~5mins with the pump on.  However, the temp. different was around 1-2 degrees, and the cooling effect was not that obvious.
    2. The required volume of water tank:
      The thermoelectric cooler was attached to a recycled box and half a bottle of water was enough to fill up  the insole
    3. If additional cooling will be required:
      Basically, natural cooling was enough for this case
    4. The workmanship of pipe bending:
      Dia 6 mm pipe was difficult to bend by bare hand. Even though the shape was alright, the insole would occupy a lot of space and the feet would not be able to fit in.

    The experiment is shown below

    Conclusion:

    1. The cooling effect has to be enhanced 
    2. The cooling pipe diameter has to be decreased

  • Conceptual System Design

    Revoxdyna • 08/25/2022 at 13:02 • 0 comments

    Considerations:

    For cool feeling generation: It is noticed that to generate a cool feeling, a few degrees lower compared with ambient temperature would do the job.

    1. For shoe modification: There were many similar shoe projects, which involve shoe modification. In this project, I hope the whole device could be transferred to a new shoe in a short period of time. Therefore, the shoe is decided not to be damaged.
    2.  For the cooling insole: The heat from the feet should be dissipated as soon as possible and the contact surface with the insole should be large. Therefore, a conductive insole should be designed/ modified.
    3.  For time management: As the project was started on 19 July 22, the lead time of the purchasing parts should be considered as well.

    Requirement:

    Therefore, the design requirement was setup as below:

    • Temperature decrease: <10 deg
    • Conductive insole
    • Large contact surface
    • The shoe should not be modified

    The process flow is quite straightforward.

    1. The warm/ room temp water is cooled down with a thermoelectric cooler.
    2. The cool water is pumped into the insole
    3. The heat from the feet is dissipated by the cooling insole
    4. Repeat 1. until equilibrium

    The following is the conceptual design