The End of the Weldon Holder Era? Haimer-USA (Villa Park, IL), for example, is proposing a whole new approach that it believes can eliminate Weldon side locks. It stems from a challenge proposed to the com- pany five years ago by Boeing and GKN. The companies were increasingly working with blocks of lightweight, high-strength, corrosion-resistant materials that are difficult to machine, such as titanium.
“They would be roughing the material and the cutting tool would pull out of the toolholder, even with milling chucks, press-fit systems, hydraulic chucks, precision collets, or shrink-fit holders,” said Brendt Holden, president, Haimer- USA. This led to unnecessary scrappage of materials and excessive tool wear and breakage, not to mention wasted time. “They wanted assurance from a system that wouldn’t allow the cutting tool to be pulled out,” Holden said. At the time, the companies were forced to go back to a Weldon-type side lock system, which has its drawbacks, such
SHARPEN SE
THE
DON’T BUY NEW DRILLS. SHARPEN THE ONES YOU ALREADY OWN
FREE trial sharpening. Send us your drills and we will sharpen them for FREE! Get Started at Darex.com
*From basic points to complex geometries
Carbide drills are expensive. The Darex XPS-16 sharpens them quickly, easily and accurately, every time.
• Easy to use - everyone in your shop can operate it • Automatically hones your drills for improved performance • Automatic 4 axis CNC sharpener
• The XPS-16 is less than 1/3rd of the price of other carbide CNC sharpeners/grinders
Haimer is so confident in its new Safe-Lock technology that it believes it will eliminate Weldon side locks in the future.
as pushing the tool off center, requir- ing the materials to be machined at relatively low rpms and the generation of high torques that can cause the cut- ter to break. By 2008, Haimer’s patented Safe-
Lock system was ready for testing. Here’s how it works: spiral-shaped grooves are ground into the cutting tool shank. In combination with correspond- ing carbide drive pins in the toolholder (available in shrink-fit, collet or hydraulic chucks), the specially shaped grooves unite frictional clamping force and posi- tive locking. That prevents the tool from twisting or even being pulled out of the chuck during extreme machining. The interplay of pullout protection and runout accuracy leads to low vibration, less tool wear and efficient machining at higher speeds. The system also allows for ad- justable tool length. In testing and in the field, the Safe-Lock system “never had pullout, could go faster and improved metal removal rates,” Holden said. Originally designed for aerospace and defense, Holden said Haimer now