Improved! iPhone Gear Case with Geneva Mechanism
by QuentinT, published
You can now buy this case from my Shapeways shop here: http://www.shapeways.com/model/997471/iphone-gear-case-for-shapeways.html?li=modelEdit
For iPhone 4/4s
This is a version of the iPhone Gear Case that I completely designed and drew myself. It is much easier to print than the first case, as well as being stronger and a better fit. The areas beneath the buttons and sliders has been removed to make them easier to use, and a cutout has been made around the headphone port so bigger jacks will fit without having to remove the case. The edges of the case are also tall enough to prevent the screen from touching when placed face down. I added a bevel to the ledges that hold the case onto the phone that makes the case very easy to print without support.
I got the Geneva Mechanism idea from jessed, and used msruggles' solidworks gear generator to create the gear profiles.
- Print one of each part, except for the 3x2.75mm pin, of which you will need two.
Print the case shell and ridge with 0.1 mm layer height, no support, and single perimeters. There is a slight bevel on the ledges that hold the case onto the phone that make it printable with no support. The bevel will only work if layer heights are low enough though. You may want to scale the case up by 1% to account for shrinking.
Print the gears with taller layer heights and single perimeters, I used 0.25 mm.
Ideally, print the pins with a fan. lower layer heights work best for strength, but anything should work.
Glue the case ridge onto the back of the case shell, making sure it lines up well and the pins still fit. You can use acetone or super glue for this.
Sand the gear faces a little bit to make sure they can spin smoothly against the case.
- Attach the gears by press fitting the pins into their corresponding holes. Look at the pictures for gear placement. After you are happy with the way the case functions, turn it over and put a dab of glue on each pin securing it to the case. I sprayed the gears with some CRC Heavy Duty Silicone, and it made the gears turn effortlessly.