2017-02-17 (F) Weekly Summary

For the second time, we released an episode out of order. We recorded and released a show on the technological singularity because it was relevant to the news. The singularity was had been mentioned in 2xCb+Mic before and some of the same concepts came up in our AI episode. All of those can be found on our show page.

Tim has been working at a fevered pace to move our show to a new site. Before we just had a lowly page with the episode list but he's built us a whole site! As of this posting, it is under construction but all the episodes are there so have a look around.

Brian - Left. Tim - Right.

Why should mounting a screen to a pair of glasses present such a problem? It shouldn't. The whole process should only take a few minutes. Nope. Two weeks. It took two weeks, four machine screws, four nuts, and 200 lines of OpenSCAD code to create a wearable display. Sunglasses protect your eyes by blocking UV light but mine protected my eyes because I didn't leave the house during daylight hours for those two weeks. They're done, I look ridiculous, I can't wait to wear them in public.

Here's how it all wrapped up.

Small bumpers were printed for the holding the screen while being able to ride on threaded rods. This configuration was similar to an X-Y table found in CNC machines or 3D printers. Of course, only ordinary hardware store threaded rod was used instead of the expensive lead-screw type.

Parts for a simple screen holder which would use threaded rods

The parts were assembled and they fit exactly how I wanted. The threaded rods contained the screen at the top and bottom while the black bumpers contained the screen on the sides.

Screen holder on bolts for easy adjustment

Designing these parts was not easy. Modeling the parts took time and coding. Attaching the parts turned out to be impractical. Even though the parts amounted to a very low profile configuration, it was too large to fit on ordinary glasses.

Adjustable screen holder that didn't fit glasses

A second model was made with a completely different approach. This version would occlude one eye in order to create a flat disc that would be glued to the glasses. In my mind, this wouldn't be difficult to attach and it wouldn't be tough to print a few extra in case the alignment wasn't perfect. It turned out that the angle this attached made it almost impossible to see the screen. More versatility was needed.

Simplest possible screen holder

I assumed that most of the project would be learning about Linux and sourcing exciting new hardware. Nope. It's been all about aligning a screen. I was able to take a day to add some of that exciting hardware. A Red Bear IoT pHat was ordered at the recommendation of Doug Copeland of the Dangerous Minds Podcast. This added Wifi and BLE without consuming any USB ports but rather it relied on the GPIO.

Red Bear IoT pHat with Wifi and BLE

After all the failed attempts at creating a suitable mounting method, it became clear the best way to gain the kind of versatility I needed was to build a set of glasses from scratch. I don't wear glasses so I learned a lot by building bad pairs. SPOILER: I learned enough to make a workable screen holder.

The first print featured a screen holder that I learned to print days ago with the eye-occluding version. Even though it didn't work I found that I could reliably print a simple rectangle that would hold the screen steady. That day I also learned that glasses need both halves in order to sit on the face or they just fall off. In the picture, you can see me holding it at the bridge of my nose in order to keep them in place.

Right half of wearable screen holder

The second attempt featured glasses that went all the way across my face. What you can't see in the picture is the temples (I learned that was the name of the little shafts that go between the lenses and the ears) are simple straight rods.

Spectacles that were able to be worn

Ear hooks had to be added to the temples in order to keep everything from sliding down my nose. While the animation is fun to watch they weren't effective glasses.

Temples were the wrong length

The modularity of temples printed separately from the rest was valuable but reprinting the temples each time a few millimeters needed to be added or subtracted was impractical. Instead, the temples were printed very short and long threaded rods made it possible to change length with only a wrench and screwdriver.

Adjustable temples

Most of the work left was simply fine-tuning the model to fit my face. This was where a parametric model was highly valuable. Correcting the model took seconds. Rendering the model took minutes. Printing the new model took an hour.

Only minor tweaks remain

A flyby animation was recorded in order to show how all the printed parts fit together. My face acted as the product holder.

Face flyby

All the parts were finally suitable, printed, and assembled. A needlessly bright, cold light was pointed right at my face and I snapped a selfie while wearing everything. In one eye I could see a bright CFL lamp and the other was looking at a Linux desktop. Not a bad night.

Picture of the final product


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