A Step into Optics

Today’s project comes in preparation for work with AR. It also tries to organize information and have a starting point for work in my own 3D printed wearables. In this case, I’ll anticipate this ideal and eventual wearable to be digital, interactive, and connected. For now, though, we need a frame.

This project’s objectives (aside from just having a frame) are three:

• experiment with structural integrity

• rapid prototyping

• elements of design

Structural integrity, ABS

Because the first step of this project is a glasses frame, we can expect many long, thin components on the model. The good news is that we can rotate the model in print software, and make “the bottom” out of any side we want. I’ll put the longest, thinnest parts of the model (the arms) right onto the print bed; that will save material in the form of supports and will increase the chances of an even print of those long thin sides. Another element of structural integrity is the “window” of the glasses, where the optical element usually rests.

This print is with ABS, or acrylonitrile butadiene styrene. Ya know, LEGOs. This stuff is known to be fickle and crumble under stress, but hey this is a prototype plus more of the sturdier PLA material is backed up in the USPS deal going on. Soon.

Prototyping

Even this first stage of a very long project is going to require two prototypes. The first is a base model, to start to build a frame of reference for further versions. Once the first is printed, I’ll examine the piece and make changes to input for version 2. This process was also used on the parallax servo casing.

This series of rapid prototyping is one of the strengths of additive manufacturing. In a matter of hours, we can bring a physical version of a digital model to reality. This ability to give your engineers/designers a physical object to hold, feel, and interact with gives design feedback that you can’t get anywhere else. When designing objects made to be worn (wearables), this importance only grows.

Classic example of this: those Invisalign folks are making a fortune off of how easily you can produce slight iterations at scale with 3D printing. Dental braces are their medium, requiring a slight tweak every week or every other week but extremely cost efficient to 3D print. I tip my hat.

The critical points which the prototype will reveal to us are general parameters for dimensions, specific parameters, for comfort/utility, and of course any changes to be made regarding structural integrity.

Elements of Design

The elements of design being considered for this project are centered around fashion and comfort. Since I don’t have optics being installed until many versions down the road, I want to build something which is comfortable, balanced, and doesn’t look half bad.

In making this frame comfortable, I found that a triangle shape sits along the side of the temple and nests above the ear quite comfortably. In future versions I’ll want to make sure that the device has a “secure” functionality. (this function would probably wrap around the ear and tighten the band around the head in order to be secure during unstable head motions.)

In terms of balance, I just need to keep this frame symmetrical. As I begin adding capabilities and optical accessories to the piece, engineering will need to be done to determine component placement to optimize for a balanced headset. It would be a disaster to load all the equipment onto the front just because that’s where the eyes are; this would cause an extraordinary amount of undue stress on the muscles in control of the neck supporting the head. If equipment can be distributed around the head, a center of balance can be achieved.

One note on this design… as mentioned above, there are many thin walls by nature of what the project is. This limits the detail at which I can print, thus limiting what types of features. I hope that in the future, a finer print nozzle and more control over the servos should fix this. Going smaller is definitely a goal.

Finally, the element of fashion. I don’t know much about glasses design but that may set me up to make something even cooler. I’m envisioning a large prototype something like Daft Punk’s helmets and an ultimate version something like Google Glass. For now, this design which I stole from a Mii:

Glasses Frame V2 in Autodesk Fusion 360