Hi guys, I machined the following fixture; 1020 Steel; 19 inches long, 6 inches wide and about .625" thick. As you can see from the pictures, over time the table begins to bow upwards in the middle. We have tried the same table 1" thick and the same problem still arises. I am at a loss as to what is causing this, any thoughts would be appreciated. I should mention that it is being held between two 6" kurt vises set 4" apart.
Thanks;
CM