To build this charger, I used the electronics of a Samsung EP-P1100 device. You need to peel off the rubber pad on the back and unscrew a few screws, then unclip the casing. There, unscrew a few screws again and gently peel off the coil. Then, glue the coil to the front plate and screw the PCB together with the metal cover using the previously removed screws. The cable should be secured using a lock screwed with two M3x10 or M3x12 screws, previously mounting two M3 nuts in the casing. Then the front plate should be pressed into the casing and you're done. I recommend using fluorescent PLA for the casing, and at night you will easily find the right place with your phone. The charger is the right size for the Samsung Galaxy S2x Ultra with a case, but it will certainly work well with many other phones.