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GeekMomProjects

Re-designed my edge-lit seven-segment digit to take advantage of the super skinny (2.7mm wide) LED strip I found. When I feel up to tackling the project, I'm going to create a thinner version of my edge-lit digital clock (geekmomprojects.com/edge-lit-s)

@geekmomprojects these are great! i'm loving the edge lit acrylic stuff

@geekmomprojects same thing, but The Cool S! I’ll buy 2, at least

@geekmomprojects I love how it takes a noticeable amount of time for the data to move through the strip.
Are you doing something to make that happen or are they just charmingly slow like that?

@ArchiteuthisFlux thank you! That's actually on purpose because I like the effect as well. There's a flag in the code to either update the digit incrementally or all at once.

@geekmomprojects @ArchiteuthisFlux that’s lovely! A friend of mine is after a large format digital radio clock. A display like this could work really well for it.

@geekmomprojects That looks really cool! Is that acrylic machined or lasercut to add the prismy reflectiness to the insides of the segments?

@tj the acrylic pieces are laser cut and I color the edges of the segments that don't border an LED strip with a silver sharpie to help reduce the light bleed at the edges. The seven digit segments are also etched in a circular pattern to help scatter the light at the flat surface.

@geekmomprojects Oh, so each segment is it's own part so you can color the edges? That's a nice detail.

@geekmomprojects This is so amazingly beautiful that I am questioning if it's legal.

@geekmomprojects This is really nice. Since I don't have access to a laser cutter, I'm thinking about doing the casing in transparent PETG. It won't be as nice but likely easier to build?

@maruel maybe...? I rely on *extremely* fine tolerances to make sure the LED strip fits in between the acrylic pieces such that the LEDs slot into notches in the acrylic pieces. It will be hard to match that precision on a printer, but there may be ways to adapt the design so it's not as critical to getting everything to fit together.

@geekmomprojects wow. Tripytronix made by mom! What wondrous world in which we dwell with such moms!

@geekmomprojects
How much more difficult would a 14-segment alphanumeric version be to make?

@bornach I don't think I could design it with this technique, because creating the edge-lit effect from inside the acrylic sheet requires that a single, unbroken LED strip winds around all the individual segments, providing equal Illumination to each one. I don't think there is a path like that to wrap a single LED strip around the segments in an alphanumeric display.

@geekmomprojects
It would be an interesting graph theory puzzle to find the smallest number of contiguous LED strips that will cover all 14-segments. Bonus points for minimizing the entry-exit points for wires.

@bornach yes - it would be interesting, but beyond my math skills I'm afraid. On the practical side, I have tried using multiple LED strips wired together in a build like this, but, inevitably, the solder joints break from stress on the wires.

@geekmomprojects @bornach google nasa wire splice to see how they do it in the space industry, that should make your solder joints more secure. Also use heat shrink tubing if you are not already. Keep up the great work , its always good to see what you come up with

@hollowman @geekmomprojects @bornach Tried this just now. Google turned up many variations this image. Did I find the right thing? Asking cause it joins 2 wires together, rather than securing a wire to the surface of a LED strip.

@PaulStoffregen @hollowman @geekmomprojects @bornach I know this as the Western Union or Lineman Splice. It is primarily meant for secure mechanical and electrical connection under tension. Very secure even without soldering but usually results in a bulkier joint.

@hollowman @bornach the solder joints that break are where the wire connects to a pad on the LED strip, and the pad itself can be quite fragile under duress, even if the solder join is reinforced. LED strip projects are significantly more stable when the number of splices is minimized.

@hollowman @bornach this particular kind of build works best when the gap between acrylic pieces is just barely wider than the acrylic strip and there isn't room for shrink tube.

@geekmomprojects @hollowman
NASA will devise a robust soldering joint when they send LED strips into space on one of their rockets or space probes

@geekmomprojects @bornach oki doki, i wasn't fully aware of the usage case.
may still come in useful somewhere else though

@geekmomprojects @hollowman @bornach The word "sorry" could also come in useful somewhere else lol

@geekmomprojects What laser do you use for the acrylic? Do you like it?

@amd I'm using a GlowForge, and while I have philosophical issues about the cloud based system, it is extremely easy to use, which I do like very much.