Thanks for that, its seems that was causing my screwed engravings. Unfortunetly it has not helped my backlash style issues.
I have taken some photos for reference. All squares were engraved using the y swing option in the dsp. The letters in the 3rd picture were cut using the dsp controller, speeding up or slowing down the cutting process had no effect on the vector cutting but did effect the engrave here are the results.
Speed 1. power 20%. Y swing
Speed 2. Power 20%. Y swing
Vector cut letters
Pen mounted to the gantry speed 1, same as first image. Strangely the lines appear quite well lined up with little if any backlash.