If you have not contacted the Robinett Family Assoc. of America you might want to see if your family is documented in their records. Enter their name in your browser and it should take you to their website.
A Robinett and variations of spelling of surname, Y-DNA Surname study has just started at Familytreedna.com. If you have a unbroken male Robinette line they would be elgible to participate.