Press Release
ref: 42T prl 031 - Crane
July 2007

42 Technology torque down the weight

Work carried out by 42 Technology for Crane Electronics has resulted in modifications to their JRS product that has significantly reduced its weight, whilst improving its high performance.

Crane Electronics, a world leader in torque, angle and pulse measurement and control systems, asked us to complete a feasibility study to reduce the size, weight and cost of one of their key products: a joint rate simulator. This is a device which has to simulate torques a wrench would experience in use and is used extensively by automotive and other manufacturing industries for calibrating torque wrenches. At the heart of this device is a computer controlled friction brake used to retard the rotation of a very low inertia shaft.

An initial study reviewed alternative mechanisms and identified several candidates that might lead to significant improvements. 42 Technology also identified that there was significant scope for improving the existing, commercially established mechanism. 42 Technology recommended that the route with the lowest risk and development time would be to incrementally improve the existing technology by selecting new materials and using FEA (Finite Element Analysis) stress modelling to improve the design.

Jeremy Carey, 42 Technology’s Engineering Manager explained “A wide range of the latest commercially available friction materials were identified, their specification and applicability to this particular requirement reviewed and a short list of candidate materials were rigorously tested. A number of materials were proven to be more effective than the original material, including the final selection which provided approximately double the coefficient of friction of the original material, but at a fraction of the cost.”

42 Technology then carried out an extensive design study, utilising the FEA capabilities of Pro-Mechanica. This indicated that we would be able to make design recommendations that would result in a weight reduction of the assembly by approximately a factor of two while keeping the stress deflection to the same level experienced by the original design. The work was then expanded to consider systems comprising two or three brakes.

Peter Everitt, Crane Electronics Commercial Director, was delighted by the success of this focused project reporting that “Together the design improvements identified by 42 Technology lead to a new product that was half the size, weight and cost of the original design.”