What geographic are are you collecting for?
Team 1640 (Downingtown/Exton, PA) is always open to home schoolers. In fact, our captain this year is home schooled. We're not district-affiliated, so anyone who's ok with the drive is welcome. Many of our students commute 30min+, some ~1 hour. (Mentors are even crazier, anywhere from 45min-2.5 hours.)
FRC 1640 - Team Sab-BOT-age - Downingtown/Exton, PA - verified by team mentor
Our FLL club is also community-based, making it open to home schoolers as well. Also, I'd check with MOE Robotics (Delaware...basically all of it), as I'm virtually positive they're open to home school students, too.
For yourselves, I count
8 teams in the Richmond area. I know some teams must have school-driven policies behind membership, but I'd think someone could at least point you in the right direction.