Building the press

phs view
One-pull press

The building of this press broke down naturally into three sub-structures; the impression mechanism, the press framework and the carriage and bed assembly. The last of these had to be tackled first as it was important to know just what size a one-pull press bed and carriage needed to be, because on it depended the spacing of the cheeks and the length of the front rails. My starting point for estimating the bed size was to make a full size drawing of the folio sheet (604 x 414mm) and mark on it the verso type area.

diag 14 v3

Centred upon this a rectangle representing the platen was drawn. This was some 30mm larger in both dimensions than the type area so as to avoid accidental misprinting. In the interests of obtaining an even impression the platen and type had both to lie across the press’s centre-line but because the type area is not centred on the page, the paper has to be offset to one or other side to print it in its correct location. Which side it is displaced towards will depend upon whether a recto or verso is being printed. Because of this offsetting of the paper away from the centre-line the press bed must be widened on both sides to avoid the paper brushing against the press cheeks during printing. In addition some space was added to both sides to allow room for the frisket frame. The dimensions which emerged were used to construct an experimental carriage and bed. This was in order to check that the whole arrangement would work and to find the distance that the bed needed to travel from under the platen to the point where the type could be inked, enabling the length of the front rails to be determined. To ensure that the bed could slide easily, the carriage was fitted with metal rails. This idea was borrowed directly from the common press. It continues to work well but I now think the more appropriate arrangement would have been to make the bed slide directly on the press framework as depicted by Dürer. The press framework was made in oak with pegged mortise and tenons used throughout.  Its dimensions  are 1.83 x 0.70 m. The framework’s cross beams; the head into which is cut the nut and the winter which supports the press bed are both substantial members fitted with tusked tenons which pass through mortises cut through the cheeks. The press uses a large wooden screw, able to rotate in the wooden nut cut in the head and is moved by a meter long wooden bar. The platen to nut distance, which has to be adjustable in order to ensure that the whole of the bar’s arc can be utilised, is managed by moving the head up and down in the cheek mortises. The spindle is fitted with a short wooden hose modelled on the one in the Dürer drawing.

Next – Making the wooden screw