Tubes

Internal Support Methods for Thin Wall Tubes Thin wall tubes are challenging for deep hole drilling because the wall can collapse under cutting forces and the tube vibrates easily. I use internal support and reduced parameters to manage these issues. Over the years, I have developed several support strategies that work reliably across different tube sizes and materials. I use a mandrel inside the tube for internal support. The mandrel fits the tube ID closely and prevents the wall from deflecting. The mandrel has a center hole that allows the drill to pass through while supporting the tube wall immediately around the cutting zone. I make my mandrels from hardened tool steel with a polished OD to reduce friction. A well-fitted mandrel reduces bore runout by 50% compared to unsupported drilling. ...

Solar thermal systems use tubes and manifolds that need deep hole drilling. The work is similar to general heat exchanger tube drilling with some material-specific considerations. Over the years, I have drilled components for parabolic trough collectors, flat plate collectors, and central receiver tower systems. Each design brings its own drilling challenges. The main components are collector tubes and distribution manifolds. Collector tubes carry heat transfer fluid and are typically made from copper or stainless steel. The manifolds that connect multiple collector tubes need drilled passages for fluid distribution. I have also worked on header boxes that distribute fluid to arrays of collectors, which require multiple cross-drilled ports at precise angles. The precision of these ports affects the flow balance across the collector array. ...