Machine pallet made of steel, dry and distortion-free machined

The pallet enables workpieces to be clamped and positioned outside the machine in order to reduce setup times. While the machine is working on one workpiece, the next workpiece can already be prepared on another pallet.

To ensure that fixtures or workpieces can be clamped precisely, machine pallets are usually precision-manufactured plates made of steel or cast iron with grid holes, T-slots, or zero-point clamping systems.

The standardized interfaces offer the advantage of exact repeat accuracy and thus higher productivity. Pallets are often even part of a pallet changer or pallet pool in an automation system, so that the machine can change pallets independently without operator intervention.

With its high strength and rigidity, steel is well suited as a material for machine pallet. It ensures precise and dimensionally stable mountings for workpieces. Steel also has good wear and temperature resistance, making it ideal for long-term use in machine tools. 

To avoid tool wear and dimensional deviations, it is important to ensure a suitable cutting speed, adequate cooling, and stable clamping conditions when machining steel. 

When machining a 3300 x 2300 mm steel pallet for the aviation industry, it was required that the pallet be machined dry. The tolerances for flatness were 0.010 mm/1000 mm and 0.25 mm/total. The roughness (Rz) of the machined pallet should be less than 4 µm. 

A tool used in the past generated a lot of surface tension and process heat during milling. This made it impossible to manufacture the pallet without distortion. After 72 hours, a distortion of more than 0.2 mm was detected on the pallet.

The test series with a Mirroworx® face milling cutter in size M and a diameter of 80 mm quickly showed distortion-free results. The Pokolm Premiumtools produced the required surface quality with high precision.

Mirroworx® processes the steel pallet without distortion and with high accuracy and precision. After 55 minutes of processing, the entire surface is measured, with maximum deviations of 0.005 mm/1000 mm and 0.01 mm/total determined, which are below the required tolerances.