A GP level prism rail for telescopes... connect this to your Vixen GP compatible telescope mount.
The STL file is a model for a gp level prism rail with length 80mm. You can put a camera screw (like the Hama camera screw thing:51656) through the slot (see last rendering image).
You can change the size of the prism rail in the openSCAD file. But there seems to be problems with the for loop for the slot...
You can even open this thing with the thingiverse customizer and change the length of the prism rail.
I added a photo of the rail mounted on my telescope mount. On top of the rail, I mounted my iphone4.
I will use this part on my Celestron ADM telescope mount.