The case of the jagged edged acrylic

Issue as reported by customer:
On the Y axis during cuts diagonal or from front to back of the machine and in some other areas, edges on acrylic appeared gagged or serrated with lines and ridges top to bottom of the work piece edge.

Originally on testing alignment I felt this was a case of poor downward alignment from mirror 3 through the lens due to an unevenly seated CO2 laser tube. However the issue was not correctly by reseating of the tube and an extensive alignment of all mirrors and the lens.
It was concluded that there was a vibration whilst running which at certain speeds caused some sort of resonance to occur, which in tern created a heavy vibration on particular movements on the X and Y axis.

Belts were inspected and the left side Y axis belt was found to be loose compared to the right side Y axis. This was tensioned.
The rails were cleaned with Scotchbrite and AutoGlym Machine & Engine Cleaner. Rails were greased with white lithium and lithium grease was pumped into the bearing carriages.
High speed tests were then run including very fast side to side, circular and up and down movements of the head in both linear and raster modes.

Cleaning and greasing the rails as well as tensioning the belts improved the quality of the cut.