You’ll soon have to tip the machine when you push buttons for do-it-yourself banking. A court ruling recently struck down Iowa’s rule that banned banks from slapping a surcharge on some A-T-M transactions, in a case that began with a few national banks that have Iowa branches. Denny Hanson, president of the Wells Fargo Bank in Grinnell, says nationally chartered banks started charging fees in Iowa, and then state-chartered banks did it, too. Hanson says the change might not affect you as much as you think.He says the fee only applies to non-customers who use another bank’s A-T-M machine. Hanson says local banks probably won’t charge their own customers to use ATMs they own. Critics say since the point of ATM use is convenience, clients don’t necessarily make it a point to travel to a cash machine owned by their own bank, but bankers say it costs them to install and service the machines, and they need a surcharge to cover that cost.