This holds a Garmin GPS device on one of my two bikes for the forthcoming holidays. It is sturdier than I thought (see http://youtu.be/WCfcyDthPXo)
I uploaded here 3 different sets (where 31.8 reaches the maximum) because the customizer could not handle the DXF profile of the GPS device. They should match the main handlebar diameters (according to the wikipedia), else tweak it with Openscad (source included as usual)
Select your handlebar diameter (works up to ~31mm fat bars), then print two "arm" STL and one "nut" STL file. It uses M3 screws.
It slices neatly on an ultimaker with the following parameters:
- 0.2 mm layers
- 1.8 mm walls (loops->infill->perimeters)
- 1.2mm bottom/top
- 30% fill
With Openscad, you'll be able to change the diameter (one value at the beginning of the SCAD source code). Too bad the customizer cannot handle this design properly.