Hi
I want to build a tablet for kids. At first I thought I can find the schematics of some SBC boards like raspberry, beagleboard,etc and remove some features like USB hosts and maybe add some others like 3G/4G onboard modem. But I don't know is it a possible thing? Is this a good way to make a simple tablet that I can sell in market? How the chinese companies make very cheap tablets?
I am very interested to doing this and ready to study!
i have the same question but you can get raspberry pi zero's schamatic make the pcb design and make the pcb(please order just one and if it isworking then order the rest)
then solder the commponets using heat gun and done, or get the raspberry pi zero and make a case then put a keyboard trackpad and install latest version of ubuntu or ubuntu mate then done! but dont forget to contact raspberry pi fundation and canonical then warn them so you use the board and the software they make, when it comes to electronics im very bad even im 14 year old teenager and i would want to help you just a littilebit 
