Hole Making Machine Based on Double Eccentric Mechanism for CFRP/TiAl6V4 Stacks

Construction parts consisting of 2-layer composite materials made of carbon fiber reinforced plastic (CFRP) laminates and TiAl6V4 still need to be machined, whereby drill holes are frequently manufactured. Recently, it is well-known that Orbital drilling, which is also called Circular milling, Planetary drilling or Spiral drilling, is superior to conventional drilling for hole making of CFRP/TiAl6V4 stacks. The author newly developed hole making machine based on Double Eccentric Mechanism so that a cutting tool driven by one built-in air motor can rotate clockwise on its own axis at high speed, simultaneously can revolve counter-clockwise on eccentric axis at low speed (Yagishita, 2012). The driving mechanism of the machine is entirely different in that respect both high speed rotation and low speed revolution of cutting tool can be created by one built-in air motor from Novator's mechanism (PCT/SE2008/050719) which needs two driving sources.The purpose of this paper is that by replacing a built-in air motor used in the previous hole making machine with a built-in AC motor it is achieved to lighten the weight of the machine and also to be handy by applying electric control device. After that hole making tests are executed to CFRP/TiAl6V4 stacks by using a new type cemented carbide endmill having 6 blades.