Very helpful in determining specific train times and schedules is the magnificent German train website Bahn.com . Another site with Europe-wide schedules is Austrian Rail. However even with these powerful tools it's tricky to match up the more frequent trains in and out of Chur and Lugano with with the Alps magnificent Bernina Express, which itself is not a simple single line but basically goes between Chur / Davos / or St Moritz Switzerland to Tirano, Italy and then on in summer by bus to Lugano, Italy. Confused? Here's the Bernina Express site. This is one of the world's great train rides and it's included in the Eurail Pass.
Note: Eurail Pass has helped to sponsor of our European family blogging adventure. Thanks Eurail Pass!