Challenge: To grind burnishing and expander rolls used in manufacturing tubes for a multitude of applications ranging from oil and gas tubes to automotive. Due to the shape of the parts which includes several tapers, the material removal is dramatic requiring several operations. Additionally the rolls are custom shapes so changeover between part types requires reshaping the grinding wheel.
Solution
The existing operation was grinding 0.050” to0.150” on a roughing pass, taking a maximum of 0.030” each pass until 0.005” of stock remained, and finish grinding 0.001”-0.002”per pass to maintainroundness,profileand10Ra surface finish on a large machine, overkill for a steel part that ranges 0.250” to 1” in diameter. Changeover time was long, several grind setups were needed to grind 0.082” of material, and 4-5 passes were needed to achieve the required surface finish and roundness.
The GT-610-CNC plunge grinds the part, maintaining 0.0001”diameter tolerance and the required shape –all in fewer passes. Removal of 0.082” takes only 113 seconds from start to finish, achieving 0.000025” roundness, with a 5 Ra surface finish, in only 3 total passes.
The operator is able to switch over from part to part, and between operations, by simply redressing the grinding wheel, using the built-in CNC roll dresser. Alternatively, one can change to a pre-dressed grinding wheel in 15-20 minutes. The setup time is further reduced with the added patented lateral work rest blade axis, since full axis control is available using one touch on the touch screen control.
