Productive Times: a high-torque conversion

END USER: Hansen Engineering Co., (310) 534-3870, www.hansenengineering.com

SOLUTION PROVIDER: JM Performance Products Inc., (800) 322-7750, www.jmperformanceproducts.com

CHALLENGE: Increase productivity and decrease machine downtime.

SOLUTION: Install high-torque retention knobs in toolholders.

Eliminating toolholder expansion provides an easy and cost-effective way to achieve high levels of performance from CNC machines and cutting tools. Expansion can occur when a standard retention knob is installed in a toolholder. Pressure exerted by thread engagement, coupled with the elastic properties of the steel used to make the toolholder, creates a bulge at the small end of the holder.

Once expansion occurs, the holder will not pull entirely into the machine spindle. As a result, the holder can’t make contact with as much as 70 percent of the spindle surface. This lack of complete contact can lead to vibration and chatter, nonrepeatability, shorter tool life, excessive spindle wear, tool runout and out-of-tolerance parts.

Hansen Engineering Co. is well aware of these problems. The Harbor City, Calif., job shop produces multiple-axis parts and major structural assemblies for the aerospace industry in two buildings on its 43,000-sq.-ft. campus. The majority of HEC’s CNC machines have 10,000-rpm to 15,000-rpm spindles.

Far Left: With a standard retention knob, taper deformation on the toolholder prevents it from properly mating
with a CNC machine tool’s spindle. Left: The high-torque retention knob from JM Performance Products enables
a toolholder to have close to 100 percent contact with the spindle. Image courtesy of Hansen Engineering