BTA Drilling Machine Reduces Weight of Helicopter Drive Shafts

The DeHoff BTA/STS 2084 drilling machine is designed for drilling on-center holes using the BTA/STS process for applications such as the manufacture of drive shafts for helicopter tail rotors.

The DeHoff BTA/STS 2084 drilling machine from Kays Engineering is designed for drilling on-center holes using the BTA/STS process for applications such as the manufacture of drive shafts for helicopter tail rotors. The shaft begins as a solid piece of high-strength alloy steel, and a center hole is drilled in a single pass using the BTA machine. This process results in a weight reduction for the finished drive shaft.

The machine has a 2" (50.8-mm) diameter drilling capacity and an 84" (2,134-mm) drilling depth. It has a single spindle with a 20-hp spindle motor. A four-speed gearbox delivers twice the torque of a standard DeHoff model. The machine can also be offered with slide travels of 36", 60" or 120" (914, 1,524 or 3,048 mm).

The machine features a cast iron drill head base with hardened and ground steel box ways, plus a hand-scraped and fitted saddle, gibs and straps instead of linear guideways and milled surfaces. This is said to damp vibration, extend tool life and improve surface finish.

Editor Pick

With Retention Knobs, Shop Sets Sight on Aerospace Machining

Mitch and Brian Olson didn’t know much about CNC machining when they started their machine shop, but they learned that if they wanted to pursue high-accuracy aerospace work, they would need to overcome a flaw inherent in V-flange tooling.