By Randy Bruce, HLI Technician
We were presented with a problem from a metal forming plant in Canada. The problem existed in the foundations they installed under their mills which are on floating pads. Since all of these machines had a basement under them they needed a way to isolate them from the rest of the vibrations created in the plant. They did this by installing the machine on top of a large cement pad that sits on top of rubber based pads. This allows the whole pad to float while isolating the machine from external vibration.
The problem they encountered was that they had no way of checking the alignment of the machine with levels. As soon as they moved the table on the machine the levels would “bottom out” from the pad floating.
By using the L-723 Ultra-Precision Triple Scan® Laser Alignment System we were able to set up on the pad and buck-in to the boring mills base ways (x-axis). This machine is a Toshiba boring mill with x, y, and z-axis travel. After shooting in to the base ways we were able to find the flatness of the x-axis ways as well as the parallelism of the table and table travel, and the parallelism of the y-axis ways and the squareness of the column for both lean and tilt, all in one set up. Because we were shot into the base ways and not looking at Earth level the machine pad could move and not affect what we were doing.
The base ways were out of flat to themselves by .020 in 20 feet, the y-axis ways were pitched up in the rear by .015 and the column was out of square by .016 in 10 feet, leaning in toward the table.
We flattened the ways to each other and had to actually realign the column to be perpendicular to the base ways.
Before the machine had been aligned the machine was cutting holes off location on the dies and all of the dies machined by this mill all had to be redone. When the dies were put in the press they did not fit together correctly, creating scrap parts. I found that they had aligned the column with a large knee fixture, and I asked if I could check it for square. We found it to be out of square to itself by .016. After completing this job they began using this mill as a qualified machine and made their masters from this machine.
They then brought us in to qualify all of their mills and benchmark them. We now have all of these machines on a routine schedule for requalification on a yearly basis.