Engraving lines still wriggley

Machine FS4060 Shendong Laser, C3D Laserboard.

The oval is a test I ran with the original M2 nano controller. After finally getting the wiring connections right for the LaserBoard I have been adjusting the following variables in the Smoothieware: feed rate between 4000 and 500 mm/min, seek rate between 24000 and 6000 mm/min, acceleration between 2500 and 500 mm/sec/sec, X and Y maximum speed between 24000 and 6000 mm/min, alpha current between 0.4 and 1.0, beta current between 0.6 and 1.2, pwm, line 160, from 400 to 500. The best result is photo 2, wriggly, intermittent, faint lines, at 30% power and various speeds. Garbage. At this point I have modified everything I can think of, sometimes one at a time, sometimes severally together, always with the same result. Weirdly, when a run a simple circle program the X axis stepper makes a loud noise, lurches into motion and smoothly runs the job. It I immediately run the same job, it runs perfectly smooth start to finish. The oval photo, and frequent checks tells me the belts, pulleys and mirror alignments are not the issue. What else can I try?

Maybe try cleaning your mirrors. It helped me in a similar situation.

if you find reason for loud screeching noise when it stops and then next time it doesnt let me know i have same issue