Phone Case Finished

Well I started the case in August... Now its January...

I was a bit of a klutz and in the middle of a bit change from the drill bit for a #2 screw through hole to an 1/8" mill bit I didn't realize that the screw on my CNC's drawbar had backed out. My CNC has a somewhat unique drawbar design that requires a spanner to tighten the collets in place. The collets are really small, only around a 1/2" at their largest dimension. I did some research one time and found out what they were, but I can't remember what they are. I vaguely remember them as ww collets, but I could be completely wrong. In any case my collets use outside threads. When the screw loosened on the drawbar it bottomed out on the collets threads. I didn't realize this and continued to turn the drawbar to tighten the mill bit into the spindle. Sadly the tiny amount of torque I put on the machine was enough to shear the 1/32" pin that slips into the collet's keyway. The collet became stuck in the spindle and the mill bit wouldn't hold in. I had to leave for school, so any machining in the Secret Underwater Base / Machine Shop had to be put off until December.

Surviving a semester of school took its toll on me and left me sleeping a lot over break. Therefore I didn't work on all of the projects I wanted to finish. The phone case turned out to take 3 days. I got lazy again and machined the center ring that surrounds the phone from polycarbonate. In my opinion it looks better than the aluminum anyways.

 This was the cursed part that I broke my spindle while making. Once I had my new spindle (which I got repaired and the bearings replaced for free) the part came out pretty quickly. I did discover that my mill bits were all fairly dull. I'll have to order a few more. Thankfully 1/8" mill bits are pretty cheap.

The case turned out exactly as awesome as I had imagined. It does have a few drawbacks...
-It is really heavy. I don't particularly mind, but I really doubt there are many other people that would want a phone that weighs as much as this one.
-It is really huge. This thing rivals a brick... enough said.
-It is sharp. I had to use cap head screws because the hex set I carry around doesn't have a key small enough to tighten a button head screw. So far I only cut my leg once. I attempted to climb over something and one of the screws dug into my leg. If I get cut again I'll replace the cap head screws with button heads.
-It needs a hex set. I'm screwed (hahaha its a pun) if I ever need to remove the battery and I don't have my hex set with me.

It may have a few drawbacks, but I love the case and will probably leave it on the phone until I replace the phone.

Phone Case - New Project

My phone was a little bit too bland for me, so I decided it needed a cool case. I couldn't find one that I liked for it, so making one in the shop was the next best option. A few years ago I had designed a case for my IPod, but I never got around to machining it because it required me to write too much code for my CNC.

It was made from 2 pieces. The front plate was simple and could all be machined in one setup, but the back piece need to have the center machined out. Aside from the time required to write out the tool paths by hand, the machine time on my CNC would have been too unbearable for me to make the case. This did however serve as the basis for my phone case concept.

I started off designing the phone case by getting the dimensions for my phone. Thankfully it wasn't one of those "ergonomically" shaped phones, so the phone was basically a rectangle with rounded corners. After taking down the dimensions I opened up SolidWorks and started playing around with different concepts. Eventually I came to this design.

The general concept was a ring that surrounded the phone and a plate on the top and bottom that held the phone in place. The ring only requried a slot to be machined around the inside perimeter. This would leave a nice little plug of material in the center that could be used for another project. This case needed #0-80 screws. Since the sides were so thick the case needed button extenders to allow me to actually use the phone. For some reason my first thought was to machine small holes in the side of the case for the buttons to slip into.  This design quickly turned my simple ring idea into a nasty 4 sided machining job. I don't have an edge finder for my CNC, so I was not in the mood to re-zero it multiple times on a single part. With ease of machining in mind I redesigned the case again.

(This render came after making the case. I got lazy and used polycarbonate instead of an aluminum ring as I had originally Intended)

This new design gave me the option to do all of the parts with single sided machining and minimal material removal. Both are things I strongly prefer when producing any part. Hopefully the case will be a quick one day project.