I linked this assignment to the final project where I will need to build two thermoelectric sets which comprise a thermoelectric device, a cold element and an heat sink. This is a critical step for the final project since the quality of the thermal groups will determine the how well the assembly will perform.
This is the the assembly design of the two sets.
The assignment focus is on molding the rectangular cold plate incorporating the convection blades obtained from a standard size aluminnium plate.
Here's s set of drawings that show the design process
CAM
Milling simulation
The milling process is made up of a series of steps which involves working different geometries and using different tools.
Part facing to prepare the raw stock for further machining
Pocket toolpath is used for machining closed curves
Boring
Contouring, leaving tabs that keep the parts attached to the stock
Creating slots
Drilling
Milling
The two bits
Gypsum mold
Preparing the blades
Mixing gypsum with water
Pouring the mix in the mold
Let it cure for a day
Unmolding
Unfortunatly, like the last picture shows, I designed the blades slots too shallow and the blades could not fit correctly. The mold could not be closed. I tried to shorten the blades but the mold broke apart!
Re-design
I modified the design, changing also the postion of the vents so that the molten metal would not pour directly on the relatively cold blades
New molds
We were confident being able to cast correctly ...
Unmolding 2
Casting
The result was not as good as expected. The gypsum, even after sevaral days was still too humid, probably also absorbing hunidity from the environment.
Tried baking the mold in my household oven. Three hours at 80°C and then cooling to ambient temperature in the switched off oven.
The resul was better (element on the right) but not sufficiently good for the purpose.
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