standard form panel dimensions therefore some means is required to form remaining openings that are smaller than standard panel dimensions the telescopic beam 80 as shown in fig8 is used for this purpose sliding members 11 are simply pulled apart or pushed together axially until the required length is achieved and the telescopic beam 80 is placed onto its intended supports the telescopic beam 80 will automatically have some positive camber that will be beneficial in keeping the underside soffit of the slab flat workmen can then custom cut plywood to the exact size required and attach it to the telescopic beams methods of attachment are well known in the art in a preferred embodiment both assemblies sliding member 11 with connector 12 attached are identical however as indicated in the foregoing description other configurations are possible the operating principal of the telescopic beam 80 in regard to the automatic generation of positive camber and elimination of the effects of operating clearance can be explained using fig9 fig9 shows the relative position of components when the beam 80 is under load vertical gaps 20 21 and 22 are key to the proper functioning of the telescopic beam gap 20 is the clearance provided to facilitate assembly of connector 12 into position at one end of sliding member 11 before the two are permanently fastened together with screw 13 note that connector 12 is pushed up tight to contact the upper lip on sliding member 11 before screw 13 is driven and tightened gap 21 is the total operating clearance that allows connector 12 to easily slide by the sliding member 11 on the left side of.