Post B6SWOt88MtTy68XxK4 by kline@mastodon.sdf.org
 (DIR) More posts by kline@mastodon.sdf.org
 (DIR) Post #B6SWOs6KC8ROuEgzrc by kline@mastodon.sdf.org
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       A successful night in the hackspace - new old Mac Mini laser engraved and another successful 10" rack conversion.Process follows.
       
 (DIR) Post #B6SWOsOl5bBbpPJib2 by kline@mastodon.sdf.org
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       For the rack mount, a quick spin through OpenSCAD after taking measurements of where the mounting screw holes are on the side of the switch.I have generic 10" 1U and 2U patterns made from https://boxes.hackerspace-bamberg.de/ that really help.After that, fire the model through PrusaSlicer and it's 1h from "print" to part, and some M3 screws to attach.
       
 (DIR) Post #B6SWOsixsTLiq4lr5k by kline@mastodon.sdf.org
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       The Mac Mini was a bit more involved, but also more interesting.1. Download LIDAR heighmap data from DEFRA (I used this data when I was doing my masters - great resource).2. Whack it all into QGIS and normalise the tiles.3. Decimate the data (went from 1m to 200m per pixel resolution) to smooth, and then run contour analysis. Clean by deleting any lines by filtering length < some hundreds of meters. Export as SVG.
       
 (DIR) Post #B6SWOt88MtTy68XxK4 by kline@mastodon.sdf.org
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       4. Take a zoomed out picture of the Mac from far away, to give you a minimally distorted reference image.5. Put it all in inkscape, using the known size of the Mac to scale to reference. Trace a red "keep out" layer we can use in lightburn to avoid tracing the laser over the plastic when we're doing the aluminium etch. (The apple logo gets a debian swirl in the end.)6. Chuck it all in lightburn.Cost:* Mac (recycled): £0.00* Open Govt Data: £0.00* QGIS: £0.00* Laser: £2.20 (11 min run)
       
 (DIR) Post #B6SWOta8glsrUzeJyS by kline@mastodon.sdf.org
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       Some things to note:* I was going to do this on our new fibre laser but didn't - it's both too small (it was originally going to be 4 carefully referenced cuts, rotating a new corner in each time, which is what the green quadrants were for) and too slow progress. Turns out the CO2 laser did a better job getting through the anodised layer *and* fits the whole cut in 1 pass.* The laser isn't 100% parallel and disperses after the focal point. This deposited some energy on the plastic/labels.
       
 (DIR) Post #B6SWOtvlONBIa3lagC by kline@mastodon.sdf.org
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       Related: the Mac Mini has a small IR sensor for use as a media centre with a remote control.I illuminated that with some oblique portion of the 30W of IR laser cutter beam.There's a real chance that sensor is toast, but I'd never use it anyway. Whoops.Finally, I would also have spent some time cleaning up the Debian swirl if I realised how many "bits" it had coming off the main swirl. It's deliberate, but on the laser it just looks a bit unclean/bitty, like a mistake.
       
 (DIR) Post #B6SWOuH27IC9e1iZpg by kline@mastodon.sdf.org
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       With the exception of the lightburn (the laser control software), everything involved here was freely licensed.OpenSCAD, Inkscape, and QGIS are all GPL.Data:* DEFRA LIDAR is UK Open Government License.* Rackmount data isn't clearly licensed, but is generated by boxes.py - GPL.* Additional geo data from OSM is ODbL (but didn't go into the final cut, was just a tool to reference data against).PrusaSlicer/XL Firmware: (A)GPL.If anyone has leads on a lightburn replacement, I'm all ears.
       
 (DIR) Post #B6SWOudMmG3klIAPdw by kline@mastodon.sdf.org
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       If you like this kind of stuff, be sure to have a look for your local hackspace/makerspace.I'm a member at rlab, Reading, UK - https://wiki.rlab.org.uk/ .You can have a look for yours on the map at https://wiki.hackerspaces.org/List_of_Hacker_Spaces .Can't see it? Don't fret, local knowledge trumps an out of date wiki. Ask around, web search, etc.And of course, you can always start your own...
       
 (DIR) Post #B6SWOurBwr7PSAdSC0 by kline@mastodon.sdf.org
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       Here's the switch happily in the rack. It doesn't need to be there, but it's a good place to store it for now.