• 3 Posts
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Joined 3 years ago
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Cake day: June 17th, 2023

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  • Interestingly, the supports could even dissolve in the main liquid ingredient of the original resin, like a cube of ice in water. This means that the material used to print structural supports could be continuously recycled: Once a printed structure’s supporting material dissolves, that mixture can be blended directly back into fresh resin and used to print the next set of parts — along with their dissolvable supports.

    Unless I’m reading this too optimistically, it seems like recovering the resin just requires adding more of the original solvent, which sounds pretty good (as long as that solvent isn’t much nastier than a regular resin solvent).










  • Interesting, it took me a while looking at your images to figure out why the original design didn’t work. The problem was that there was no solution that could avoid at least one extremely long bridge, and that bridge also forced the adjacent bridges to be “wrong” (though maybe if it printed the super long bridges first, it could’ve made the rest short).

    I don’t have much to add besides being surprised the problem was more interesting than it first seemed…and I don’t accept that you were being an idiot because it want immediately obvious to me either. Or I am one too :)










  • The 7333A is a linear regulator, which means it drops voltage by converting power to heat. Typically those make sense when the input voltage is close to the output voltage or the load is very small. If it’s getting too hot, the load is high enough that the efficiency will be very bad…whether or not this is a problem depends on your application.

    Some random site claims 170mA and another claims up to 400mA. 170mA * 8.7V (12V in minus 3.3V out) = about 1.5 watts, which is too much for a TO-92 package.

    Can you use a tiny buck converter instead? Or a larger package for the linear regulator that can add a small heat sink?

    As for your actual circuit, the second transistor is an interesting idea (you’re using it to invert the state so you can have the GPIO pulled in the non-problematic direction?) and I don’t have enough experience to give further suggestions.