Mollart sets up helicopter drive shaft cell

The cell, which includes a Mollart BTA heavy duty, deep hole drilling machine, which has a capacity to produce holes between 22 and 60 mm by 1,600 mm deep, is paired with an XYZ Proturn SLX 1630 lathe. The drilling and turning process, developed by Mollart's application team around the S132 toughened steel shafts that are up to 36 mm dia by 500 mm long, required an initial deep hole to be produced. The shaft is then profile turned before being sent back to the customer for controlled heat treatment. Shafts are then returned to Mollart for finish machining. At this point, the main bore is finished to 23.9 mm dia, with a 34 mm dia counterbore machined to a depth of 360 mm. Tolerances are all within 0.05 mm, but a 10 micron TIR concentricity is vital in the application of the component, which has to be strictly maintained between the two bores and outside diameter. To achieve this, Mollart has developed special ballnose style BTA counterbore tools that are piloted from the previously drilled main bore. In particular, the tooling design has to ensure all edges have a radius without sharp corners that could create stress points. Each component has to be 100% certified by Mollart's quality team, due to the safety critical requirements.