Cutting tool assemblies with runout higher than 0.0003” (0.008mm) can leave waviness and ripples on the walls of the part.
The tool assembly must be balanced for high-speed applications. A tool assembly that is out of balance can cause vibration and leave a wavy and rippled finish.
Balance the tool holder with the cutting tool. If you cannot balance the tool assembly, replace it with one that you can balance.
Incorrect servo gain or acceleration parameters can cause the machine to leave a wavy and rippled surface finish.
Contact your Haas Factory Outlet to have the machine's parameters checked and corrected if necessary.
Machine accessories like the chip conveyor, chip auger  or Side Mount Tool Changer (SMTC)  can introduce vibration into the machine causing waviness/ripples to appear in the side walls of your part.
Turn off the chip auger, chip conveyor and pre-stage the next tool before the finish cut starts.
Vibrations from external sources can transfer into the machined finish and appear as waviness and ripples.
Before you start the finish cut, stop nearby forklift traffic, crane operation, and welding operations.