Deep hole solution

Citation

(2000), "Deep hole solution", Aircraft Engineering and Aerospace Technology, Vol. 72 No. 6. https://doi.org/10.1108/aeat.2000.12772fab.003

Deep hole solution

Deep hole solution

Keywords: Mollart Engineering, Drilling

Mollart Engineering's innovative approach is reported to have provided a solution to generate a network of holes in a vacuum tooling plate at a 375.1 length to diameter ratio, for use in the production of aircraft wing sections on a routing machine (Plate 4).

Taken from a flame-cut, mild steel blank some three metres long by 1.5m wide and weighing around 1.6 tonnes, a total of 24 holes were required 8mm diameter through the length of the plate. As the batch was for only ten tables, Mollart Engineering's production engineers used standard clamps and performed individual alignment of each plate on a Mollart CNC knee-type, deep hole drilling machine.

Plate 4 Mollart's application expertise provides 375:1 hole solution for vacuum tooling plate

The 8mm diameter holes were initially drilled half way through with a single drill from one side of the three metre vacuum plate using Mollart Botek gundrills. The component was then turned 180°, realigned and then drilled to break through to the previous holes in the centre.

Such is the capability of the process that it easily met the tolerance specification which demanded no more than one-third of a hole mismatch or 1.2mm runout for each hole at breakthrough after drilling the 1,500mm hole depth from each side. The total depth of 3,000mm, using an 8mm gundrill equates to 375:1 length to diameter ratio.

Details available from Mollart Limited. Tel: +44 (0) 208 391 2282.