A friend of mine was good enough to build me one of these focusers for my scope, and then I proceeded to basically blow it and my laptop up last Saturday due to my stupidity. Basically, to cut a long story short I connected everything up correctly and in the right order and then proceeded to connect the wrong voltage up to my USB hub. I blew up the hub, blew the Arduino, the motor board and the USB3 hub built into my nice shiny new laptop... Needless to say I felt like a bit of a prize idiot that night. The Laptop is away being repaired and should be returned next Friday hopefully (9th September). I reordered the damaged parts from ebay and repaired the focuser and its now back in 100% working order. It is a wonderful piece of electronics for controlling the focus. Don't know what I would do if I ever had to return to manual focusing.... lol