Abstract: A system is disclosed for holding a panel in a u-channel comprising a rocking grip configured to be positioned in the u-channel on a first side of the panel and a tilting grip configured to be positioned in the u-channel on a second side of the panel, opposite the first side for adjusting an angular position of the panel. The rocking grip includes a rotatable rocking plate for abutting the first side of the panel. The tilting grip includes a tilting plate for abutting the second side of the panel a moveable top cam for rotating the tilting plate in a first direction and a moveable bottom cam for rotating the tilting plate in a second direction, opposite the first direction.