I would like to know any videos or help topics on designing a cutting tool (Bit) for a hand held rotary tool?
Have a Wonderful Day
Matt Lombard's recent blog post covers some of your options.
You are most liklley going to use Helical, Loft or Sweeps.
Not an easy part to "mock up" unless you have real driving dimensions
take a look at Matt's blog here: http://community.plm.automation.siemens.com/t5/Solid-Edge-Community-Blog/Helical-Features/ba-p/2609