5 ms·

Excellent. I wonder how practical it would be to put each mirror on a servo so that you can change the image in real time?

deleted 5y ago
[deleted]
ortusdux 5y ago
Depends on the desired scale - https://www.youtube.com/watch?v=9nb8mM3uEIc https://www.youtube.com/watch?v=9nb8mM3uEIc
- nomel 5y ago
  This is quite a bit different. DLP like projectors are binary: straight forward or somewhere away. The layout of the grid of mirrors matches the layout of the dots you can illuminate, in the image. Something like OP has would require some pretty serious angular precision.
  - beecafe 5y ago
    You could use holography/beamforming to steer a beam from a DLP, although it would be just a small % of the original power.
    - nomel 5y ago
      I think the beautify of the mirror system is that it's direct, understandable/observable, and nice to look at by itself, even if it's not showing an image. It's elegant. If you use beam formers and DLPs, you're just making an overcomplicated DLP projector that's going to look like an overcomplicated DLP projector.
      - beecafe 5y ago
        Absolutely. And it'll keep working on a sandy beach far from any power source.
mrnotcrazy 5y ago
https://www.youtube.com/watch?v=WwCmzwSE98o&list=RDCMUCUbDcUPed50Y_7KmfCXKohA&start_radio=1&rv=WwCmzwSE98o&t=517 https://www.youtube.com/watch?v=WwCmzwSE98o&list=RDCMUCUbDcU... I don't know if you would need a server for each mirror? but you would need.... two axis of rotation? and making a mechanical system that slowly moved mirror by mirror to update the position might be more complex.
anfractuosity 5y ago
You can get MEMS microscanners although they're probably a bit small - https://en.wikipedia.org/wiki/Microscanner https://en.wikipedia.org/wiki/Microscanner but they can orientate a mirror on two axes. This one looks a pretty decent size - https://www.sercalo.com/products/mems-mirrors/mm160110-2 https://www.sercalo.com/products/mems-mirrors/mm160110-2
- jacquesm 5y ago
  Swiss made precision optical gear. I think the price of that little mirror just might make your head spin.
jjk166 5y ago
You'd probably want to use galvos instead of servos for this application (high speed/precision, low load mass).
- jacquesm 5y ago
  Or piezo.
martinky24 5y ago
Look up "Adaptive Optics". That's literally what you describe :) They've got a somewhat niche use in astrophotography.
regularfry 5y 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.
- regularfry 5y ago
  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...

deleted 5y ago

[deleted]

ortusdux 5y ago

Depends on the desired scale - https://www.youtube.com/watch?v=9nb8mM3uEIc https://www.youtube.com/watch?v=9nb8mM3uEIc

nomel 5y ago
This is quite a bit different. DLP like projectors are binary: straight forward or somewhere away. The layout of the grid of mirrors matches the layout of the dots you can illuminate, in the image. Something like OP has would require some pretty serious angular precision.
- beecafe 5y ago
  You could use holography/beamforming to steer a beam from a DLP, although it would be just a small % of the original power.
  - nomel 5y ago
    I think the beautify of the mirror system is that it's direct, understandable/observable, and nice to look at by itself, even if it's not showing an image. It's elegant. If you use beam formers and DLPs, you're just making an overcomplicated DLP projector that's going to look like an overcomplicated DLP projector.
    - beecafe 5y ago
      Absolutely. And it'll keep working on a sandy beach far from any power source.

mrnotcrazy 5y ago

https://www.youtube.com/watch?v=WwCmzwSE98o&list=RDCMUCUbDcUPed50Y_7KmfCXKohA&start_radio=1&rv=WwCmzwSE98o&t=517 https://www.youtube.com/watch?v=WwCmzwSE98o&list=RDCMUCUbDcU... I don't know if you would need a server for each mirror? but you would need.... two axis of rotation? and making a mechanical system that slowly moved mirror by mirror to update the position might be more complex.

anfractuosity 5y ago

You can get MEMS microscanners although they're probably a bit small - https://en.wikipedia.org/wiki/Microscanner https://en.wikipedia.org/wiki/Microscanner but they can orientate a mirror on two axes. This one looks a pretty decent size - https://www.sercalo.com/products/mems-mirrors/mm160110-2 https://www.sercalo.com/products/mems-mirrors/mm160110-2

jacquesm 5y ago
Swiss made precision optical gear. I think the price of that little mirror just might make your head spin.

jjk166 5y ago

You'd probably want to use galvos instead of servos for this application (high speed/precision, low load mass).

jacquesm 5y ago
Or piezo.

martinky24 5y ago

Look up "Adaptive Optics". That's literally what you describe :) They've got a somewhat niche use in astrophotography.

regularfry 5y 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.

regularfry 5y ago
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...