One of the things that I wanted to get my fiance this Christmas was an iPhone case. Normally cases are made of plastic or sometimes aluminum - I could make an aluminum case but I didn't think she would be into that, and an injection molder to get a high quality plastic case is not something I have (though I am slowly designing one - though it's nowhere near close to even being built). I stumbled upon a site that sold wooden cases. At around $130 they were cost prohibitive but I really liked them, and more importantly so did my fiance, so I decided to make one.
Before construction, the case had to be designed. Apple has dimensioned drawings for all of their products in the developer portal. It is the iPhone 3g under "dimensional drawings" if you are making a case for other iPods they have drawings for them there as well.
I used the drawings to get the location and size of the camera, volume buttons, headphone port, lock button, silent/loud switch, speaker, microphone, and the dock connector. I somewhat arbitrarily chose to make the sides of the case 3mm thick tapering down to the thinnest part of the back at a thickness of 2.4mm. From the dimensioned drawings I was able to get the dimensions of the rectangular blocks that would then be hollowed out and contoured to fit the iPhone.
Although I would have preferred to use ash, it was two days before Christmas and I didn't have any quality lumber lying around or time to hunt for a supplier, so I went to home depot and got a foot of oak.
I cut the pieces down to roughly the correct size in a band saw then, since I don't have many woodworking tools, I brought them down to size in a mill. Of course a mill is total overkill - a sander/planer/file/chisel would have sufficed. Do note the lack of tolerances in my drawings - this isn't great. Since I designed the case and was machining it, I knew the tolerances in my mind.
The next thing I did was cut the holes and slots for all of the buttons and ports. I used a 3/32" endmill for the volume, speaker, microphone, and lock button slot. I used a 3/16" endmill to make the dock connector slot, a 7mm drill for the headphone port, and a 6mm drill for the camera port. I then roughly milled out the cavity for the iPhone.
I knew it would be faster to make a bit to cut the perimeter "slot" of the case than to carve it so I made one out of stainless steel. It's stainless because I happened to find a piece in a scrap bin. I was able to get the dimensions of the contour by importing the image into solidworks, tracing a spline onto it, then taking dimensions of closely spaced points along the spline. With the dimensions of the points and a lot of patience I was able to turn myself into a "manual CNC machine" moving the lathe a tiny bit at a time to each point. In the end I had the tool seen below. Normally I would harden and anneal the bit (as well as NOT make it out of stainless steel) but since I was making a small cut in oak I just went for it.
Back at the mill I mounted the newly made bit in a collet and cut the perimeter of the case. I used a cutout of the profile from the dimensioned drawings to check the fit of the iphone. Note that the iphone has the same contour shape all the way around meaning the bit could can cut all sides.
The bit only cut the perimeter and once again I didn't trust myself to hand carve the contour accurately on my first attempt. Again I did a slight variation of the manual CNC trick - using solidworks I traced a spline onto the "bottom" of the iPhone side view and was able get a set of points that represented the contour of the back of the iPhone. Using a 1/4" ball end mill, I cut the contours the same way as I cut the router bit. You can see the cuts from the mill in the pictures below.
The final "machining" step was to cut a small channel up to the volume button to allow the phone to be put in the case without the buttons interfering. I used a small high speed dremel cutter for that.
Shaping the outside of the case was done with a drum sander on a dremel, and a hand sander for the finishing work. I used a micrometer and a dial indicator on a stand to check the wall thickness. This was completely overkill but it worked.
The final step was to make the buttons. I milled down scrap pieces of oak to the correct button sizes, leaving a small lip to keep them from falling out of the case. The pictures show this better than my words. Using needle files I filed the ends of the buttons round and gave the volume buttons a valley in the middle so they mimicked the feel of the iPhone volume button. I also had to carve a small recess for the buttons to fit in flush with the inside of the case. I used the high speed dremel cutter for this.
I taped up all the ports on my iPhone, put the case on it and match sanded the two pieces so they were flush. I didn't stain it because I wasn't sure what color my fiance would want. It turns out that she likes the natural look best so I will only be giving it a clear coat of varnish. Note that in the pictures the case is not match sanded or varnished.
That's it! I did enlarge and taper the hole for the vibrate/loud switch with a round needle file to make it more accessible. I believe this case could be made without a mill or lathe. The important thing is making templates with the drawings from the apple developer page to check your dimensions.