Over the last few years I have seen a few threads here about portable CNC routers.I have seen those located by cables or following striped tape cited and don't have much faith in either.Then, a few days ago, I stumbled on this machine and although it will never compete with even a ShopBot and has some limitations I do believe it would be a viable option for a lot of people. https://www.yetitool.com/ I will add that I have never seen one in use and have no connection with the company.If you need such a device it may be worth a minute or two of your time.