Screw-down TOSLink Launcher

prusaprinters

<p>The original files, including KiCad support files, can be found in the github repo, at <a href="https://github.com/jbm9/toslink_launcher">github.com/jbm9/toslink_launcher</a>.</p><p>TOSLink is a really handy fiber optic cable: you can buy them easily, reasonably cheaply, and in various lengths. &nbsp;They are meant for audio, but they're just flexible lightpipes at the end of the day.</p><p>You can buy TOSLink connectors that solder onto PCBs, but they only come with red LEDs (which is used in the audio application). &nbsp;If you want to put arbitrary colors through them, it gets complicated. &nbsp;So, I decided to make a little connector that would let me mount a TOSLink cable over an arbitrary surface mount LED.</p><p>The STL included here assumes that your printer needs 0.2mm of fudge-factor on each side to get good results on interior holes. &nbsp;It is designed to put the end of the fiber cable 0.7mm above the surface it's bolted down to.</p><p>The mounting arrangement for this is two holes 17mm apart. &nbsp;I recommend using 5mm drill hits for these, as you will need to align the fiber optics perfectly with the LED underneath it. &nbsp;To do this, you want to move the connector around a little after it's mounted to the PCB. &nbsp;Putting M3 screws through a 5mm hole lets you move up to 1mm in any direction from center, which should be good enough.</p><p>The recommended PCB footprint is an 8mm circle around those M5s, and a 13mm circle about your LED. &nbsp;(I never claimed this was a space-efficient footprint…)</p><p>This is a spreadsheet-driven FreeCAD file: if you need to adjust the squeeze-out fudge factor, or the height of the LED, etc, you can open the Spreadsheet in the file, tweak the values in that spreadsheet (don't forget to include “mm” or FreeCAD will have a pedantic little fit), and it should update the model. &nbsp;You can then Activate the “TOSLink Launcher001” Body object by double-clicking on it, and then File &gt; Export, and type in “toslink_launcher_foo.stl” (you also need to add the STL there, FreeCAD's great).</p><p>This is also a reasonable starting point for the TOSLink connector; there are precious few models using it, so hopefully this is a good starting-off point for anyone else who wants to use these cables for alternate purposes.</p>