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by regularfry 1685 days ago
Almost trivial, if you're prepared to make the mirrors a bit bigger. I've got a 7-element array on my workbench right now. You want two servos per mirror, one for each axis. I'm using flexures for linkages between the servos and the mirrors, and universal joints made of magnets and ball bearings to hold everything together. The mirror tiles I'm using are 110mm across, flat-to-flat, which are bigger than this example, and that makes layout and assembly straightforward in a way that it wouldn't be if everything was smaller. Everything's printed in PETG, raspberry pi pico for brains driving a pca9685 PWM driver over i2c. The linkage geometry is the only hard part, the CAD and printing was pretty much a one-weekend project.
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Should probably point out that with 2 servos per mirror you can match surface normals but not surface offsets. You can make each individual mirror match the gradient of a curve, but you can't make a curve like the parabolic dish in the GitHub link without a third servo per mirror. I'm waiting for more parts to arrive for that...