The top bar is nominally 9 mm thick to make the fitting of the cover frames easier. (one required per frame)

The central side bar is a standard DN/1 component. (two required per frame)

Bottom bars are standard B1 items that might be used to make a DN/1 frame. (two required per frame)

The middle strut effectively divides the frame into two equal halves and is secured at the top end by a screw through the centre of the top bar. (one required per frame)

The cover frame sides have comb jointed corners for strength as the material is only 9 mm thick, the slots are 9 mm deep. (eight required per frame)

Unlike the sides of the cover frame which are all the same, the top and bottom pieces are different in order to accommodate the narrow main frame bottom bars and provide sideways location in the recess caused by the narrowness of the bars. (four required per frame)

The bottom piece is not exactly symmetrical which leaves 0.5 mm spare each side of the bottom bar when the cover is fitted. (four required per frame)

Capping piece can be made from thin birch ply or from glass fibre printed circuit substrate... Hole positions are not dimensioned, but they must fall between the wires. The number of screws and thus holes required will depend on the stiffness of the material used. (eight required per frame)

Locating pegs made from dowelling are fixed in the upper corners of the main frame. (four required per frame)

Small sheet metal hooks are available from hardware stores (mine came from Wilkinson's), these ensure that the cover frames remain in place. (eight required per frame)

The Drone excluder Grid (DRONEX) requires cutting in half for this twin paneled version. This can be achieved using a hacksaw that has a fine toothed blade fitted. It may help to wrap several thicknesses of masking tape around the centre of the grid. before marking and cutting as the tape will stop the blade from slipping.

All dimensions that are not listed in the chart are the same as the ones shown on the National drawings for each and every hive type.