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| Both sides previous revisionPrevious revisionNext revision | Previous revisionNext revisionBoth sides next revision | ||
| mission:resources:picojet [2014/05/04 09:21] – [Mold] chrono | mission:resources:picojet [2014/07/09 12:15] – [Design] chrono | ||
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| ==== Ghetto style silicone processing ==== | ==== Ghetto style silicone processing ==== | ||
| - | The biggest challenge are the tiny air bubbles which inevitably occur while mixing the portions/ | + | To get a usable, final product made out of silicone, we need to take care of the tiny air bubbles, which inevitably occur while mixing the portions/ |
| **So how do we get them bubbles out?** | **So how do we get them bubbles out?** | ||
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| Once the portions are mixed, there usually is only a small time window to pour the mix until it starts to bind, but that is not enough time for the bubbles to " | Once the portions are mixed, there usually is only a small time window to pour the mix until it starts to bind, but that is not enough time for the bubbles to " | ||
| - | When you put your final mix into the freezer | + | Put your final mix into the freezer, it slows the binding process almost to a complete standstill which gives the trapped air enough time to leave the mix. After 24 hours, pull out the frozen mix and pour it carefully and slowly into your mold. Put the whole mold with the silicone into the freezer for another couple of hours to give the air, trapped by the pouring process, time to leave. Then just carefully take the mold out and let it bind for 24 hours at room temperature. |
| + | |||
| + | <WRAP round tip> | ||
| + | * Mind the size of freezers you can easily access when designing/ | ||
| + | * Make sure your mold is tight and sealed, so that the silicone can't get out | ||
| + | </ | ||
| ==== Heating-Element ==== | ==== Heating-Element ==== | ||
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| === Calculations === | === Calculations === | ||
| + | |||
| + | First, we need to figure out how much energy we have to put into the fluid in order to get from room temperature to 45°C: | ||
| <x 14> | <x 14> | ||
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| </x> | </x> | ||
| + | Now we can determine how much heating power we need to deliver that amount of energy in a reasonable time-frame: | ||
| <x 14> | <x 14> | ||
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| ==== Heat Reflector ==== | ==== Heat Reflector ==== | ||
| + | |||
| + | Since the heater radiates the energy in all directions we want to reflect the heat going to the bottom upwards again, so that we don't waste energy there. Tests have shown that rescue blankets for cars (the gold/silver foil) can help with that, so a piece of this foil was inserted between the bottom glass and the silicone footer (silver side up, as this side reflects heat). | ||
| ==== Prove-of-Concept Test ==== | ==== Prove-of-Concept Test ==== | ||
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| === Impeller === | === Impeller === | ||
| + | |||
| + | This was the first approach, by simply cutting the tubes and some ABS material in a half-circle shape and then gluing them onto the tube. The next test should be, if we couldn' | ||
| {{: | {{: | ||
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| {{tag> | {{tag> | ||
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| + | ~~DISCUSSION~~ | ||