<p>I am interested in experimenting with the building of a large parabolic primary mirror constructed from 4&quot; hexagon mirrors mounted on a &quot;rough&quot; parabolic surface with either 3 screw adjustments for each individual mirror or (eventually) Arduino controlled adjusters.  Any constructive advise on methods or procedure would be most helpful.</p>

CC BY-SA 4.0
2021-07-22T06:48:00.350Z
That sounds very hard.  How much experience have you had in mirror making?  I don't think this is an obvious first project.
James K
CC BY-SA 4.0
2021-07-22T11:41:17.393Z
I you would like to make a solar concentrator for boiling water, this can be done with screws. But if you want to make even a very low power telescope you'll need a computer program and detailed image analysis to know how your Arduino-controlled adjusters should tilt each segment. If you have two rings of hexagons that's 18 mirrors x 3 degrees of freedom per mirror (height, and x and y tilts), or 54 independent degrees of freedom. All you have is a blurry image and what's needed is a computer program that can analyze the image and dither all the axes to figure out how to converge on
uhoh
CC BY-SA 4.0
2021-07-22T23:32:40.740Z
While the process of hand-grinding and figuring a one-piece mirror for amateurs is quite well understood and documented, I thing figuring a segment of a paraboloid without a sophisticated computer-controlled grinding machine would be impossible, and I don't think it is possible to divide an already-figured mirror into segments without destroying its figure.
antlersoft
CC BY-SA 4.0
2021-07-23T16:10:41.657Z
Did anyone do the calculation or simulation on the goodness of imaging, if that were done with flat 1st-surface mirrors (which are much more readily available)?
planetmaker
<telescope><telescope-lens><mirror-making>
Can you advise on the construction of a large segmented primary mirror (hobbiest)?
Mike L
# Can you advise on the construction of a large segmented primary mirror (hobbiest)?

(Asked by: username_0 on 2021-07-22)

I am interested in experimenting with the building of a large parabolic primary mirror constructed from 4" hexagon mirrors mounted on a "rough" parabolic surface with either 3 screw adjustments for each individual mirror or (eventually) Arduino controlled adjusters. Any constructive advise on methods or procedure would be most helpful.

**Tags:** telescope, telescope-lens, mirror-making

> **Comments:**
> **username_1**: That sounds very hard.  How much experience have you had in mirror making?  I don't think this is an obvious first project.  
> **username_2**: I you would like to make a solar concentrator for boiling water, this can be done with screws. But if you want to make even a very low power telescope you'll need a computer program and detailed image analysis to know how your Arduino-controlled adjusters should tilt each segment. If you have two rings of hexagons that's 18 mirrors x 3 degrees of freedom per mirror (height, and x and y tilts), or 54 independent degrees of freedom. All you have is a blurry image and what's needed is a computer program that can analyze the image and dither all the axes to figure out how to converge on  
> **username_3**: While the process of hand-grinding and figuring a one-piece mirror for amateurs is quite well understood and documented, I thing figuring a segment of a paraboloid without a sophisticated computer-controlled grinding machine would be impossible, and I don't think it is possible to divide an already-figured mirror into segments without destroying its figure.  
> **username_4**: Did anyone do the calculation or simulation on the goodness of imaging, if that were done with flat 1st-surface mirrors (which are much more readily available)?  

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## 0 answers

