Double right-angle drilling head speeds wing spar production

Citation

(2001), "Double right-angle drilling head speeds wing spar production", Aircraft Engineering and Aerospace Technology, Vol. 73 No. 6. https://doi.org/10.1108/aeat.2001.12773fab.006

Double right-angle drilling head speeds wing spar production

Double right-angle drilling head speeds wing spar production

Keywords: Centreline, Drilling

A double-ended, right-angle head has been manufactured by Centreline Machine Tool to enable a vertical-spindle KTM Maxitrace to drill and tap horizontal holes in the ends of aircraft wing spars at Alvis Vehicles Ltd, Telford (see Plate 6). Better known for armoured vehicle manufacture, the company undertakes a certain amount of subcontract work, in this case for the aerospace industry, to fill spare capacity in the machine shop.

Plate 6 A double right angle Centreline head similar to the one supplied to Alvis Vehicles for drilling and tapping the ends of aircraft wing spars

Centreline informs us that all metalcutting on the wing spars can now be completed in one hit, whereas previously the component had to be transferred to a horizontal spindle machine for second-operation drilling and tapping. Not having to handle the part between two machines reportedly reduces both lead time and cost of production. Moreover, there is said to be no risk of losing accuracy as a result of refixturing.

Called RAD 225-D, the unit is a standard Centreline head with a flat on the base of the housing to achieve the correct hole position. Tool centre to base distance is 45mm, allowing 2mm of clearance from the machine bed. The standard "225" head radius of 50mm would have been impracticable for this application.

The Centreline head drills and taps 17.5mm diameter 1 M20 holes in the ends of the spars. The unit runs at 3,000rpm with 1:1 ratio and the ER40 collets can hold tooling up to 30mm diameter. The collets are tension-tapping to allow floating movement in the direction of travel (X-axis). Weight of the head is 17.5kg and it is capable of being automatically changed into the machine tool spindle.

Further details are available from Centreline Machine Tool Company Limited. Tel: +44 (0) 24 7635 4111; Fax: +44 (0) 24 7635 4222; E-mail: sales@centreline.com; Web site: www.centreline.com