[HN Gopher] Show HN: CNC Microscopy for Fun
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       Show HN: CNC Microscopy for Fun
        
       Author : anfractuosity
       Score  : 88 points
       Date   : 2024-09-19 20:59 UTC (1 days ago)
        
 (HTM) web link (www.anfractuosity.com)
 (TXT) w3m dump (www.anfractuosity.com)
        
       | alnwlsn wrote:
       | Would be really cool to read a whole CD this way. Actually, that
       | wouldn't sound any different. You could read an LP though.
        
         | FuriouslyAdrift wrote:
         | For vinyl, there's always the laser player (used for
         | preservation, too)
         | 
         | https://www.elpj.com/
        
         | anfractuosity wrote:
         | I just added an extra image where you can see contours being
         | drawn around the 'pits' of the CD-ROM. I need to improve the
         | speed of the autofocus etc. before I can image a whole CD heh.
        
       | 2four2 wrote:
       | This is basically how an optical CMM (OMM) works. There are
       | tricks to determining and calibrating out alignment issues and
       | determining snapshot viability, and you're touching on both of
       | them. Very well done!
        
         | anfractuosity wrote:
         | Thanks, I assume https://en.wikipedia.org/wiki/Coordinate-
         | measuring_machine is what you're referring to, which look
         | interesting, hadn't come across them before.
        
       | uSoldering wrote:
       | If you photograph and stitch a panorama of a CD at a resolution
       | with the data visible and distribute it under your copyright, is
       | it piracy?
        
         | IncreasePosts wrote:
         | Yes.
        
         | shadowpho wrote:
         | Piracy is not a technical definition but a legal one.
         | 
         | If you zip/print/scan/ocr/train ML on/restore from ML its still
         | piracy even though none of the pixels are directly transferred.
        
       | molticrystal wrote:
       | So you wanted to take pictures of cdroms with a microscope, going
       | on a decent detour and the other way you can make a microscope
       | from a disc player which is a really cool project [0]
       | 
       | [0] "Hacking CD/DVD/Blu-ray for Biosensing"
       | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6066758/
        
       | contingencies wrote:
       | I am also just about to attach my microscope to a CNC system, but
       | not for taking pictures of two dimensional manufactured objects
       | but rather for Z-stacking use in biological light microscopy.
       | Probably some horizontal stitching too.
       | 
       | The prompt was that someone gave me a broken project which they
       | had never finished (small-scale benchtop CNC system which is
       | highly rigid and heavy but had no wiring, an ancient power supply
       | and a busted spindle motor). I considered finishing the project
       | but the overall size was too small to be very useful for any CNC
       | work I would want (we used to have a large scale commercial
       | 4-axis!). Therefore I am retrofitting a new control system
       | [acquired], rationalizing the power supply [done], and clamping
       | on a USB industrial camera based microscope [clamp acquired,
       | intermediate mounting plate TBD].
       | 
       | On my current microscope mount it's really annoying to zoom a
       | little, take a shot, zoom a little, take a shot since there's a
       | high chance of bumping the sample or some slight vibration
       | affecting a shot, and it's very hard to move a tiny amount due to
       | high-friction macro adjustment interface. I was part-way through
       | designing a fix, with some axis modifications for a motor mount,
       | but then realised it would be easier to just redesign the mount
       | from scratch rather than retrofit a one-off modification. Before
       | allocating time to get that done, the CNC fell in to my lap.
        
       | joshu wrote:
       | greaseweazle for CDs
        
       | dekhn wrote:
       | I started with this but ended up designing my own system around a
       | vertical 4040 aluminum extrusion post and various 3d-printed
       | components including an XY stage (often costs $10K or more) and a
       | Z stage (for focus). It was quite challenging to get everything
       | to line up in a single optical axis and keep the dust out but the
       | results have been quite good- I wrote my own software after
       | trying to get micromanager to work, and can do large acquisitions
       | (25x75mm, AKA a single microscope slide) as well as real-time
       | object-detector based tracking.
       | 
       | It's remarkably hard to equal or best a $150 scope from Amscope
       | in terms of optical quality, it's automating their stages that is
       | tricky.
        
       | Animats wrote:
       | Nice. Try to image a vinyl record. Maybe someone can write
       | something to play such images. The Library of Congress has such a
       | system, called IRENE, but it was very expensive.[1] This might be
       | a low-cost approach.
       | 
       | [1] https://en.wikipedia.org/wiki/IRENE_(technology)
        
       | ElCapitanMarkla wrote:
       | Getting that Z Axis perfectly level across the run is going to be
       | fun at this scale.
        
         | anfractuosity wrote:
         | Heh yeah, I split the area to be imaged into squares, and run
         | autofocus in the middle of the square. Then use a 'snake' like
         | XY pattern across that square to create images.
         | 
         | But I need to dramatically increase the speed of this process
         | to use across a whole CD etc.
        
       | flimsypremise wrote:
       | I'm currently doing something similar to build a photographic
       | film scanner. I will say that I've found that moving the optics
       | is generally much more error and vibration prone than moving the
       | target. I'm actually using a 2 axis microscope stage as the basis
       | for my scanner, ironically enough, and CNC spindle z-axis for
       | focus.
        
         | anfractuosity wrote:
         | Cool, that sounds really interesting, what size film are you
         | using that for? Is illuminating the film evenly hard too?
        
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