For my new, easier to print version check out this link: http://www.thingiverse.com/thing:65810

This is an iPhone 4/4s case with moving gears on the back. It clips onto my phone perfectly with no wiggle room, and is still pretty easy to take off.

I altered the original rivets to make them easier to print, and scaled the main case a little bit for a better fit. Other than that, only part orientations have been changed.

The source files can be found at the following links.

http://www.instructables.com/id/IPhone-Cover-for-Engineers/

http://grabcad.com/library/iphone-cover-for-engineers

1. Print the main case, using support. I believe I used 1.5 mm spaced honeycomb support. I printed 0.175 mm layers with solid fill to give extra strength.

2. Print the gears. The first number in each gear name is the number of teeth, and the final number is how many you need. Use whichever layer height works best for your printer, but I recommend single walls so that there is room for some fill, making the gears stronger. I printed them with three walls the first time and it left many spaces between the perimeters that were too small to fill.

3. Print the rivets. I recommend using single walls, and low layer heights to give extra strength. I would also print slowly with z lift.

4. Clean up all of the parts with an sharp knife, and some 220 grit sandpaper. Test fit all of the gears. When you're satisfied with the fit push the rivet in place.

5. After you are completely happy with the case, make sure the rivets are pushed in securely, then flip the case over so you can see the holes for the rivets. Put a dab of thick CA glue on each rivet to make sure they don't fall out. Thinner glue may leak through and lock the gears in place.

6. Wait for the glue to dry, then snap your phone in place and enjoy!

You need to shave a little bit of material away around the silencing slider if you have the iPhone 4s