I signed over legal cusody of my two little girls a year ago I have visitation rights but my father who has the legal cusody is not letting me see them. Can I get physical or legal rights to my children back?

Usually 1 years time is too short to re-address the situation. Courts like to spread it out a little (2-years min) so the child/ren don't bounce around. Why had you given up custody before?

Why not just try to enforce your visitation rights?

To help further we would need to know the reasons you signed over custody, whether it was ratified by a court and your general locale.

If you have visitation rights, take him to the court that issued the orders and force him to allow visits.