Second part arrives

The transparent visor part arrived yesterday from Shapeways.

It’s not very transparent, but apparently with sanding and polishing it becomes clear. It’s also very fragile – a piece broke off when I tried to attach it to the first part and it had to be glued back on.

Now that I’ve got my hands on the part I can see a few things that need improving.

1. The visor needs to be thicker. It’s currently 1.2mm thick, and will be difficult to sand and polish without breaking. At least 1.5mm next time.
2. It needs a shorter focal length. The visor sits too far forward on the brim of the cap and doesn’t really provide fully field-of-view coverage. Shortening the focal length will move it back and increase its curvature, hopefully solving both problems.
3. The attachment mechanism needs rethinking. The tolerances are too tight – this can be fixed with sanding, but that’s not suitable for mass production. It can fail when the visor material is too fragile. It’s too complex for injection moulding. And it partly obscures the phone’s screen.

Still, I’ll proceed with what I’ve got. Get the visor sanded and polished, then hopefully mirror coated, and see if it works.

 

---